hgbook

annotate en/ch06-collab.xml @ 1019:746a888fb41b

some typo and better french translation
author André Sintzoff <andre.sintzoff@gmail.com>
date Mon Nov 30 10:57:42 2009 +0100 (2009-11-30)
parents 477d6a3e5023
children
rev   line source
bos@559 1 <!-- vim: set filetype=docbkxml shiftwidth=2 autoindent expandtab tw=77 : -->
bos@559 2
bos@559 3 <chapter id="cha:collab">
bos@572 4 <?dbhtml filename="collaborating-with-other-people.html"?>
bos@559 5 <title>Collaborating with other people</title>
bos@559 6
bos@584 7 <para id="x_44a">As a completely decentralised tool, Mercurial doesn't impose
bos@559 8 any policy on how people ought to work with each other. However,
bos@559 9 if you're new to distributed revision control, it helps to have
bos@559 10 some tools and examples in mind when you're thinking about
bos@559 11 possible workflow models.</para>
bos@559 12
bos@559 13 <sect1>
bos@559 14 <title>Mercurial's web interface</title>
bos@559 15
bos@584 16 <para id="x_44b">Mercurial has a powerful web interface that provides several
bos@559 17 useful capabilities.</para>
bos@559 18
bos@584 19 <para id="x_44c">For interactive use, the web interface lets you browse a
bos@559 20 single repository or a collection of repositories. You can view
bos@559 21 the history of a repository, examine each change (comments and
bos@675 22 diffs), and view the contents of each directory and file. You
bos@675 23 can even get a view of history that gives a graphical view of
bos@675 24 the relationships between individual changes and merges.</para>
bos@675 25
bos@675 26 <para id="x_44d">Also for human consumption, the web interface provides
bos@675 27 Atom and RSS feeds of the changes in a repository. This lets you
bos@674 28 <quote>subscribe</quote> to a repository using your favorite
bos@559 29 feed reader, and be automatically notified of activity in that
bos@559 30 repository as soon as it happens. I find this capability much
bos@559 31 more convenient than the model of subscribing to a mailing list
bos@559 32 to which notifications are sent, as it requires no additional
bos@559 33 configuration on the part of whoever is serving the
bos@559 34 repository.</para>
bos@559 35
bos@584 36 <para id="x_44e">The web interface also lets remote users clone a repository,
bos@559 37 pull changes from it, and (when the server is configured to
bos@559 38 permit it) push changes back to it. Mercurial's HTTP tunneling
bos@559 39 protocol aggressively compresses data, so that it works
bos@559 40 efficiently even over low-bandwidth network connections.</para>
bos@559 41
bos@584 42 <para id="x_44f">The easiest way to get started with the web interface is to
bos@559 43 use your web browser to visit an existing repository, such as
bos@559 44 the master Mercurial repository at <ulink
bos@675 45 url="http://www.selenic.com/repo/hg">http://www.selenic.com/repo/hg</ulink>.</para>
bos@559 46
bos@592 47 <para id="x_450">If you're interested in providing a web interface
bos@675 48 to your own repositories, there are several good ways to do
bos@675 49 this.</para>
bos@675 50
bos@676 51 <para id="x_69d">The easiest and fastest way to get started in an informal
bos@675 52 environment is to use the <command role="hg-cmd">hg
bos@592 53 serve</command> command, which is best suited to short-term
bos@592 54 <quote>lightweight</quote> serving. See <xref
bos@559 55 linkend="sec:collab:serve"/> below for details of how to use
bos@675 56 this command.</para>
bos@675 57
bos@701 58 <para id="x_69e">For longer-lived repositories that you'd like to
bos@701 59 have permanently available, there are several public hosting
bos@701 60 services available. Some are free to open source projects,
bos@701 61 while others offer paid commercial hosting. An up-to-date list
bos@701 62 is available at <ulink
bos@701 63 url="http://www.selenic.com/mercurial/wiki/index.cgi/MercurialHosting">http://www.selenic.com/mercurial/wiki/index.cgi/MercurialHosting</ulink>.</para>
bos@675 64
bos@676 65 <para id="x_6a0">If you would prefer to host your own repositories, Mercurial
bos@675 66 has built-in support for several popular hosting technologies,
bos@675 67 most notably CGI (Common Gateway Interface), and WSGI (Web
bos@675 68 Services Gateway Interface). See <xref
bos@675 69 linkend="sec:collab:cgi"/> for details of CGI and WSGI
bos@559 70 configuration.</para>
bos@559 71 </sect1>
bos@675 72
bos@559 73 <sect1>
bos@559 74 <title>Collaboration models</title>
bos@559 75
bos@584 76 <para id="x_451">With a suitably flexible tool, making decisions about
bos@559 77 workflow is much more of a social engineering challenge than a
bos@559 78 technical one. Mercurial imposes few limitations on how you can
bos@559 79 structure the flow of work in a project, so it's up to you and
bos@559 80 your group to set up and live with a model that matches your own
bos@559 81 particular needs.</para>
bos@559 82
bos@559 83 <sect2>
bos@559 84 <title>Factors to keep in mind</title>
bos@559 85
bos@584 86 <para id="x_452">The most important aspect of any model that you must keep
bos@559 87 in mind is how well it matches the needs and capabilities of
bos@559 88 the people who will be using it. This might seem
bos@559 89 self-evident; even so, you still can't afford to forget it for
bos@559 90 a moment.</para>
bos@559 91
bos@584 92 <para id="x_453">I once put together a workflow model that seemed to make
bos@559 93 perfect sense to me, but that caused a considerable amount of
bos@559 94 consternation and strife within my development team. In spite
bos@559 95 of my attempts to explain why we needed a complex set of
bos@559 96 branches, and how changes ought to flow between them, a few
bos@559 97 team members revolted. Even though they were smart people,
bos@559 98 they didn't want to pay attention to the constraints we were
bos@559 99 operating under, or face the consequences of those constraints
bos@559 100 in the details of the model that I was advocating.</para>
bos@559 101
bos@584 102 <para id="x_454">Don't sweep foreseeable social or technical problems under
bos@559 103 the rug. Whatever scheme you put into effect, you should plan
bos@559 104 for mistakes and problem scenarios. Consider adding automated
bos@559 105 machinery to prevent, or quickly recover from, trouble that
bos@559 106 you can anticipate. As an example, if you intend to have a
bos@559 107 branch with not-for-release changes in it, you'd do well to
bos@559 108 think early about the possibility that someone might
bos@559 109 accidentally merge those changes into a release branch. You
bos@559 110 could avoid this particular problem by writing a hook that
bos@559 111 prevents changes from being merged from an inappropriate
bos@559 112 branch.</para>
bos@675 113 </sect2>
bos@675 114
bos@559 115 <sect2>
bos@559 116 <title>Informal anarchy</title>
bos@559 117
bos@584 118 <para id="x_455">I wouldn't suggest an <quote>anything goes</quote>
bos@559 119 approach as something sustainable, but it's a model that's
bos@559 120 easy to grasp, and it works perfectly well in a few unusual
bos@559 121 situations.</para>
bos@559 122
bos@584 123 <para id="x_456">As one example, many projects have a loose-knit group of
bos@559 124 collaborators who rarely physically meet each other. Some
bos@559 125 groups like to overcome the isolation of working at a distance
bos@674 126 by organizing occasional <quote>sprints</quote>. In a sprint,
bos@559 127 a number of people get together in a single location (a
bos@559 128 company's conference room, a hotel meeting room, that kind of
bos@559 129 place) and spend several days more or less locked in there,
bos@559 130 hacking intensely on a handful of projects.</para>
bos@559 131
bos@675 132 <para id="x_457">A sprint or a hacking session in a coffee shop are the perfect places to use the
bos@592 133 <command role="hg-cmd">hg serve</command> command, since
bos@592 134 <command role="hg-cmd">hg serve</command> does not require any
bos@592 135 fancy server infrastructure. You can get started with
bos@592 136 <command role="hg-cmd">hg serve</command> in moments, by
bos@592 137 reading <xref linkend="sec:collab:serve"/> below. Then simply
bos@592 138 tell the person next to you that you're running a server, send
bos@592 139 the URL to them in an instant message, and you immediately
bos@592 140 have a quick-turnaround way to work together. They can type
bos@592 141 your URL into their web browser and quickly review your
bos@592 142 changes; or they can pull a bugfix from you and verify it; or
bos@592 143 they can clone a branch containing a new feature and try it
bos@592 144 out.</para>
bos@559 145
bos@675 146 <para id="x_458">The charm, and the problem, with doing things
bos@675 147 in an ad hoc fashion like this is that only people who know
bos@675 148 about your changes, and where they are, can see them. Such an
bos@675 149 informal approach simply doesn't scale beyond a handful
bos@675 150 people, because each individual needs to know about
bos@675 151 <emphasis>n</emphasis> different repositories to pull
bos@675 152 from.</para>
bos@675 153 </sect2>
bos@675 154
bos@559 155 <sect2>
bos@559 156 <title>A single central repository</title>
bos@559 157
bos@584 158 <para id="x_459">For smaller projects migrating from a centralised revision
bos@559 159 control tool, perhaps the easiest way to get started is to
bos@559 160 have changes flow through a single shared central repository.
bos@559 161 This is also the most common <quote>building block</quote> for
bos@559 162 more ambitious workflow schemes.</para>
bos@559 163
bos@584 164 <para id="x_45a">Contributors start by cloning a copy of this repository.
bos@559 165 They can pull changes from it whenever they need to, and some
bos@559 166 (perhaps all) developers have permission to push a change back
bos@559 167 when they're ready for other people to see it.</para>
bos@559 168
bos@584 169 <para id="x_45b">Under this model, it can still often make sense for people
bos@559 170 to pull changes directly from each other, without going
bos@559 171 through the central repository. Consider a case in which I
bos@559 172 have a tentative bug fix, but I am worried that if I were to
bos@559 173 publish it to the central repository, it might subsequently
bos@559 174 break everyone else's trees as they pull it. To reduce the
bos@559 175 potential for damage, I can ask you to clone my repository
bos@559 176 into a temporary repository of your own and test it. This
bos@559 177 lets us put off publishing the potentially unsafe change until
bos@559 178 it has had a little testing.</para>
bos@559 179
bos@675 180 <para id="x_45c">If a team is hosting its own repository in this
bos@675 181 kind of scenario, people will usually use the
bos@675 182 <command>ssh</command> protocol to securely push changes to
bos@675 183 the central repository, as documented in <xref
bos@592 184 linkend="sec:collab:ssh"/>. It's also usual to publish a
bos@675 185 read-only copy of the repository over HTTP, as in
bos@675 186 <xref linkend="sec:collab:cgi"/>. Publishing over HTTP
bos@675 187 satisfies the needs of people who don't have push access, and
bos@675 188 those who want to use web browsers to browse the repository's
bos@675 189 history.</para>
bos@675 190 </sect2>
bos@675 191
bos@675 192 <sect2>
bos@675 193 <title>A hosted central repository</title>
bos@675 194
bos@676 195 <para id="x_6a1">A wonderful thing about public hosting services like
bos@675 196 <ulink url="http://bitbucket.org/">Bitbucket</ulink> is that
bos@675 197 not only do they handle the fiddly server configuration
bos@675 198 details, such as user accounts, authentication, and secure
bos@675 199 wire protocols, they provide additional infrastructure to make
bos@675 200 this model work well.</para>
bos@675 201
bos@676 202 <para id="x_6a2">For instance, a well-engineered hosting service will let
bos@675 203 people clone their own copies of a repository with a single
bos@675 204 click. This lets people work in separate spaces and share
bos@675 205 their changes when they're ready.</para>
bos@675 206
bos@676 207 <para id="x_6a3">In addition, a good hosting service will let people
bos@675 208 communicate with each other, for instance to say <quote>there
bos@675 209 are changes ready for you to review in this
bos@675 210 tree</quote>.</para>
bos@675 211 </sect2>
bos@675 212
bos@559 213 <sect2>
bos@559 214 <title>Working with multiple branches</title>
bos@559 215
bos@584 216 <para id="x_45d">Projects of any significant size naturally tend to make
bos@559 217 progress on several fronts simultaneously. In the case of
bos@559 218 software, it's common for a project to go through periodic
bos@559 219 official releases. A release might then go into
bos@559 220 <quote>maintenance mode</quote> for a while after its first
bos@559 221 publication; maintenance releases tend to contain only bug
bos@559 222 fixes, not new features. In parallel with these maintenance
bos@559 223 releases, one or more future releases may be under
bos@559 224 development. People normally use the word
bos@559 225 <quote>branch</quote> to refer to one of these many slightly
bos@559 226 different directions in which development is
bos@559 227 proceeding.</para>
bos@559 228
bos@584 229 <para id="x_45e">Mercurial is particularly well suited to managing a number
bos@559 230 of simultaneous, but not identical, branches. Each
bos@559 231 <quote>development direction</quote> can live in its own
bos@559 232 central repository, and you can merge changes from one to
bos@559 233 another as the need arises. Because repositories are
bos@559 234 independent of each other, unstable changes in a development
bos@559 235 branch will never affect a stable branch unless someone
bos@675 236 explicitly merges those changes into the stable branch.</para>
bos@559 237
bos@584 238 <para id="x_45f">Here's an example of how this can work in practice. Let's
bos@559 239 say you have one <quote>main branch</quote> on a central
bos@567 240 server.</para>
bos@567 241
bos@567 242 &interaction.branching.init;
bos@567 243
bos@584 244 <para id="x_460">People clone it, make changes locally, test them, and push
bos@567 245 them back.</para>
bos@559 246
bos@584 247 <para id="x_461">Once the main branch reaches a release milestone, you can
bos@559 248 use the <command role="hg-cmd">hg tag</command> command to
bos@567 249 give a permanent name to the milestone revision.</para>
bos@567 250
bos@567 251 &interaction.branching.tag;
bos@567 252
bos@584 253 <para id="x_462">Let's say some ongoing
bos@567 254 development occurs on the main branch.</para>
bos@567 255
bos@567 256 &interaction.branching.main;
bos@567 257
bos@584 258 <para id="x_463">Using the tag that was recorded at the milestone, people
bos@567 259 who clone that repository at any time in the future can use
bos@567 260 <command role="hg-cmd">hg update</command> to get a copy of
bos@567 261 the working directory exactly as it was when that tagged
bos@567 262 revision was committed.</para>
bos@567 263
bos@567 264 &interaction.branching.update;
bos@559 265
bos@584 266 <para id="x_464">In addition, immediately after the main branch is tagged,
bos@675 267 we can then clone the main branch on the server to a new
bos@567 268 <quote>stable</quote> branch, also on the server.</para>
bos@567 269
bos@567 270 &interaction.branching.clone;
bos@559 271
bos@675 272 <para id="x_465">If we need to make a change to the stable
bos@675 273 branch, we can then clone <emphasis>that</emphasis>
bos@675 274 repository, make our changes, commit, and push our changes
bos@675 275 back there.</para>
bos@567 276
bos@567 277 &interaction.branching.stable;
bos@567 278
bos@584 279 <para id="x_466">Because Mercurial repositories are independent, and
bos@567 280 Mercurial doesn't move changes around automatically, the
bos@567 281 stable and main branches are <emphasis>isolated</emphasis>
bos@675 282 from each other. The changes that we made on the main branch
bos@567 283 don't <quote>leak</quote> to the stable branch, and vice
bos@567 284 versa.</para>
bos@559 285
bos@675 286 <para id="x_467">We'll often want all of our bugfixes on the stable
bos@559 287 branch to show up on the main branch, too. Rather than
bos@675 288 rewrite a bugfix on the main branch, we can simply pull and
bos@559 289 merge changes from the stable to the main branch, and
bos@675 290 Mercurial will bring those bugfixes in for us.</para>
bos@675 291
bos@675 292 &interaction.branching.merge;
bos@675 293
bos@675 294 <para id="x_468">The main branch will still contain changes that
bos@675 295 are not on the stable branch, but it will also contain all of
bos@675 296 the bugfixes from the stable branch. The stable branch
bos@675 297 remains unaffected by these changes, since changes are only
bos@675 298 flowing from the stable to the main branch, and not the other
bos@675 299 way.</para>
bos@675 300 </sect2>
bos@675 301
bos@559 302 <sect2>
bos@559 303 <title>Feature branches</title>
bos@559 304
bos@584 305 <para id="x_469">For larger projects, an effective way to manage change is
bos@559 306 to break up a team into smaller groups. Each group has a
bos@559 307 shared branch of its own, cloned from a single
bos@559 308 <quote>master</quote> branch used by the entire project.
bos@559 309 People working on an individual branch are typically quite
bos@559 310 isolated from developments on other branches.</para>
bos@559 311
bos@591 312 <figure id="fig:collab:feature-branches">
bos@591 313 <title>Feature branches</title>
bos@591 314 <mediaobject>
dongsheng@655 315 <imageobject><imagedata width="100%" fileref="figs/feature-branches.png"/></imageobject>
bos@591 316 <textobject><phrase>XXX add text</phrase></textobject>
bos@591 317 </mediaobject>
bos@591 318 </figure>
bos@559 319
bos@584 320 <para id="x_46b">When a particular feature is deemed to be in suitable
bos@559 321 shape, someone on that feature team pulls and merges from the
bos@559 322 master branch into the feature branch, then pushes back up to
bos@559 323 the master branch.</para>
bos@675 324 </sect2>
bos@675 325
bos@559 326 <sect2>
bos@559 327 <title>The release train</title>
bos@559 328
bos@674 329 <para id="x_46c">Some projects are organized on a <quote>train</quote>
bos@559 330 basis: a release is scheduled to happen every few months, and
bos@559 331 whatever features are ready when the <quote>train</quote> is
bos@559 332 ready to leave are allowed in.</para>
bos@559 333
bos@584 334 <para id="x_46d">This model resembles working with feature branches. The
bos@559 335 difference is that when a feature branch misses a train,
bos@559 336 someone on the feature team pulls and merges the changes that
bos@559 337 went out on that train release into the feature branch, and
bos@559 338 the team continues its work on top of that release so that
bos@559 339 their feature can make the next release.</para>
bos@675 340 </sect2>
bos@675 341
bos@559 342 <sect2>
bos@559 343 <title>The Linux kernel model</title>
bos@559 344
bos@584 345 <para id="x_46e">The development of the Linux kernel has a shallow
bos@559 346 hierarchical structure, surrounded by a cloud of apparent
bos@559 347 chaos. Because most Linux developers use
bos@559 348 <command>git</command>, a distributed revision control tool
bos@559 349 with capabilities similar to Mercurial, it's useful to
bos@559 350 describe the way work flows in that environment; if you like
bos@559 351 the ideas, the approach translates well across tools.</para>
bos@559 352
bos@584 353 <para id="x_46f">At the center of the community sits Linus Torvalds, the
bos@559 354 creator of Linux. He publishes a single source repository
bos@559 355 that is considered the <quote>authoritative</quote> current
bos@559 356 tree by the entire developer community. Anyone can clone
bos@559 357 Linus's tree, but he is very choosy about whose trees he pulls
bos@559 358 from.</para>
bos@559 359
bos@584 360 <para id="x_470">Linus has a number of <quote>trusted lieutenants</quote>.
bos@559 361 As a general rule, he pulls whatever changes they publish, in
bos@559 362 most cases without even reviewing those changes. Some of
bos@559 363 those lieutenants are generally agreed to be
bos@559 364 <quote>maintainers</quote>, responsible for specific
bos@559 365 subsystems within the kernel. If a random kernel hacker wants
bos@559 366 to make a change to a subsystem that they want to end up in
bos@559 367 Linus's tree, they must find out who the subsystem's
bos@559 368 maintainer is, and ask that maintainer to take their change.
bos@559 369 If the maintainer reviews their changes and agrees to take
bos@559 370 them, they'll pass them along to Linus in due course.</para>
bos@559 371
bos@584 372 <para id="x_471">Individual lieutenants have their own approaches to
bos@559 373 reviewing, accepting, and publishing changes; and for deciding
bos@559 374 when to feed them to Linus. In addition, there are several
bos@559 375 well known branches that people use for different purposes.
bos@559 376 For example, a few people maintain <quote>stable</quote>
bos@559 377 repositories of older versions of the kernel, to which they
bos@559 378 apply critical fixes as needed. Some maintainers publish
bos@559 379 multiple trees: one for experimental changes; one for changes
bos@559 380 that they are about to feed upstream; and so on. Others just
bos@559 381 publish a single tree.</para>
bos@559 382
bos@584 383 <para id="x_472">This model has two notable features. The first is that
bos@559 384 it's <quote>pull only</quote>. You have to ask, convince, or
bos@559 385 beg another developer to take a change from you, because there
bos@559 386 are almost no trees to which more than one person can push,
bos@559 387 and there's no way to push changes into a tree that someone
bos@559 388 else controls.</para>
bos@559 389
bos@584 390 <para id="x_473">The second is that it's based on reputation and acclaim.
bos@559 391 If you're an unknown, Linus will probably ignore changes from
bos@559 392 you without even responding. But a subsystem maintainer will
bos@559 393 probably review them, and will likely take them if they pass
bos@559 394 their criteria for suitability. The more <quote>good</quote>
bos@559 395 changes you contribute to a maintainer, the more likely they
bos@559 396 are to trust your judgment and accept your changes. If you're
bos@559 397 well-known and maintain a long-lived branch for something
bos@559 398 Linus hasn't yet accepted, people with similar interests may
bos@559 399 pull your changes regularly to keep up with your work.</para>
bos@559 400
bos@584 401 <para id="x_474">Reputation and acclaim don't necessarily cross subsystem
bos@559 402 or <quote>people</quote> boundaries. If you're a respected
bos@559 403 but specialised storage hacker, and you try to fix a
bos@559 404 networking bug, that change will receive a level of scrutiny
bos@559 405 from a network maintainer comparable to a change from a
bos@559 406 complete stranger.</para>
bos@559 407
bos@584 408 <para id="x_475">To people who come from more orderly project backgrounds,
bos@559 409 the comparatively chaotic Linux kernel development process
bos@559 410 often seems completely insane. It's subject to the whims of
bos@559 411 individuals; people make sweeping changes whenever they deem
bos@559 412 it appropriate; and the pace of development is astounding.
bos@559 413 And yet Linux is a highly successful, well-regarded piece of
bos@559 414 software.</para>
bos@675 415 </sect2>
bos@675 416
bos@559 417 <sect2>
bos@559 418 <title>Pull-only versus shared-push collaboration</title>
bos@559 419
bos@584 420 <para id="x_476">A perpetual source of heat in the open source community is
bos@559 421 whether a development model in which people only ever pull
bos@559 422 changes from others is <quote>better than</quote> one in which
bos@559 423 multiple people can push changes to a shared
bos@559 424 repository.</para>
bos@559 425
bos@584 426 <para id="x_477">Typically, the backers of the shared-push model use tools
bos@559 427 that actively enforce this approach. If you're using a
bos@559 428 centralised revision control tool such as Subversion, there's
bos@559 429 no way to make a choice over which model you'll use: the tool
bos@559 430 gives you shared-push, and if you want to do anything else,
bos@559 431 you'll have to roll your own approach on top (such as applying
bos@559 432 a patch by hand).</para>
bos@559 433
bos@675 434 <para id="x_478">A good distributed revision control tool will
bos@675 435 support both models. You and your collaborators can then
bos@675 436 structure how you work together based on your own needs and
bos@675 437 preferences, not on what contortions your tools force you
bos@675 438 into.</para>
bos@559 439 </sect2>
bos@559 440 <sect2>
bos@559 441 <title>Where collaboration meets branch management</title>
bos@559 442
bos@592 443 <para id="x_479">Once you and your team set up some shared
bos@592 444 repositories and start propagating changes back and forth
bos@592 445 between local and shared repos, you begin to face a related,
bos@592 446 but slightly different challenge: that of managing the
bos@592 447 multiple directions in which your team may be moving at once.
bos@592 448 Even though this subject is intimately related to how your
bos@592 449 team collaborates, it's dense enough to merit treatment of its
bos@592 450 own, in <xref linkend="chap:branch"/>.</para>
bos@559 451 </sect2>
bos@559 452 </sect1>
bos@675 453
bos@559 454 <sect1>
bos@559 455 <title>The technical side of sharing</title>
bos@559 456
bos@584 457 <para id="x_47a">The remainder of this chapter is devoted to the question of
bos@675 458 sharing changes with your collaborators.</para>
bos@559 459 </sect1>
bos@675 460
bos@559 461 <sect1 id="sec:collab:serve">
bos@559 462 <title>Informal sharing with <command role="hg-cmd">hg
bos@559 463 serve</command></title>
bos@559 464
bos@584 465 <para id="x_47b">Mercurial's <command role="hg-cmd">hg serve</command>
bos@559 466 command is wonderfully suited to small, tight-knit, and
bos@559 467 fast-paced group environments. It also provides a great way to
bos@559 468 get a feel for using Mercurial commands over a network.</para>
bos@559 469
bos@584 470 <para id="x_47c">Run <command role="hg-cmd">hg serve</command> inside a
bos@559 471 repository, and in under a second it will bring up a specialised
bos@559 472 HTTP server; this will accept connections from any client, and
bos@559 473 serve up data for that repository until you terminate it.
bos@559 474 Anyone who knows the URL of the server you just started, and can
bos@559 475 talk to your computer over the network, can then use a web
bos@559 476 browser or Mercurial to read data from that repository. A URL
bos@559 477 for a <command role="hg-cmd">hg serve</command> instance running
bos@559 478 on a laptop is likely to look something like
bos@559 479 <literal>http://my-laptop.local:8000/</literal>.</para>
bos@559 480
bos@584 481 <para id="x_47d">The <command role="hg-cmd">hg serve</command> command is
bos@559 482 <emphasis>not</emphasis> a general-purpose web server. It can do
bos@559 483 only two things:</para>
bos@559 484 <itemizedlist>
bos@584 485 <listitem><para id="x_47e">Allow people to browse the history of the
bos@559 486 repository it's serving, from their normal web
bos@559 487 browsers.</para>
bos@559 488 </listitem>
bos@584 489 <listitem><para id="x_47f">Speak Mercurial's wire protocol, so that people
bos@559 490 can <command role="hg-cmd">hg clone</command> or <command
bos@559 491 role="hg-cmd">hg pull</command> changes from that
bos@559 492 repository.</para>
bos@559 493 </listitem></itemizedlist>
bos@584 494 <para id="x_480">In particular, <command role="hg-cmd">hg serve</command>
bos@559 495 won't allow remote users to <emphasis>modify</emphasis> your
bos@559 496 repository. It's intended for read-only use.</para>
bos@559 497
bos@584 498 <para id="x_481">If you're getting started with Mercurial, there's nothing to
bos@559 499 prevent you from using <command role="hg-cmd">hg serve</command>
bos@559 500 to serve up a repository on your own computer, then use commands
bos@559 501 like <command role="hg-cmd">hg clone</command>, <command
bos@559 502 role="hg-cmd">hg incoming</command>, and so on to talk to that
bos@559 503 server as if the repository was hosted remotely. This can help
bos@559 504 you to quickly get acquainted with using commands on
bos@559 505 network-hosted repositories.</para>
bos@559 506
bos@559 507 <sect2>
bos@559 508 <title>A few things to keep in mind</title>
bos@559 509
bos@584 510 <para id="x_482">Because it provides unauthenticated read access to all
bos@559 511 clients, you should only use <command role="hg-cmd">hg
bos@559 512 serve</command> in an environment where you either don't
bos@559 513 care, or have complete control over, who can access your
bos@559 514 network and pull data from your repository.</para>
bos@559 515
bos@584 516 <para id="x_483">The <command role="hg-cmd">hg serve</command> command
bos@559 517 knows nothing about any firewall software you might have
bos@559 518 installed on your system or network. It cannot detect or
bos@559 519 control your firewall software. If other people are unable to
bos@559 520 talk to a running <command role="hg-cmd">hg serve</command>
bos@559 521 instance, the second thing you should do
bos@559 522 (<emphasis>after</emphasis> you make sure that they're using
bos@559 523 the correct URL) is check your firewall configuration.</para>
bos@559 524
bos@584 525 <para id="x_484">By default, <command role="hg-cmd">hg serve</command>
bos@559 526 listens for incoming connections on port 8000. If another
bos@559 527 process is already listening on the port you want to use, you
bos@559 528 can specify a different port to listen on using the <option
bos@559 529 role="hg-opt-serve">-p</option> option.</para>
bos@559 530
bos@584 531 <para id="x_485">Normally, when <command role="hg-cmd">hg serve</command>
bos@559 532 starts, it prints no output, which can be a bit unnerving. If
bos@559 533 you'd like to confirm that it is indeed running correctly, and
bos@559 534 find out what URL you should send to your collaborators, start
bos@559 535 it with the <option role="hg-opt-global">-v</option>
bos@559 536 option.</para>
bos@559 537 </sect2>
bos@559 538 </sect1>
bos@675 539
bos@559 540 <sect1 id="sec:collab:ssh">
bos@559 541 <title>Using the Secure Shell (ssh) protocol</title>
bos@559 542
bos@584 543 <para id="x_486">You can pull and push changes securely over a network
bos@559 544 connection using the Secure Shell (<literal>ssh</literal>)
bos@559 545 protocol. To use this successfully, you may have to do a little
bos@559 546 bit of configuration on the client or server sides.</para>
bos@559 547
bos@675 548 <para id="x_487">If you're not familiar with ssh, it's the name of
bos@675 549 both a command and a network protocol that let you securely
bos@675 550 communicate with another computer. To use it with Mercurial,
bos@675 551 you'll be setting up one or more user accounts on a server so
bos@675 552 that remote users can log in and execute commands.</para>
bos@559 553
bos@584 554 <para id="x_488">(If you <emphasis>are</emphasis> familiar with ssh, you'll
bos@559 555 probably find some of the material that follows to be elementary
bos@559 556 in nature.)</para>
bos@559 557
bos@559 558 <sect2>
bos@559 559 <title>How to read and write ssh URLs</title>
bos@559 560
bos@584 561 <para id="x_489">An ssh URL tends to look like this:</para>
bos@559 562 <programlisting>ssh://bos@hg.serpentine.com:22/hg/hgbook</programlisting>
bos@559 563 <orderedlist>
bos@584 564 <listitem><para id="x_48a">The <quote><literal>ssh://</literal></quote>
bos@559 565 part tells Mercurial to use the ssh protocol.</para>
bos@559 566 </listitem>
bos@584 567 <listitem><para id="x_48b">The <quote><literal>bos@</literal></quote>
bos@559 568 component indicates what username to log into the server
bos@559 569 as. You can leave this out if the remote username is the
bos@559 570 same as your local username.</para>
bos@559 571 </listitem>
bos@584 572 <listitem><para id="x_48c">The
bos@559 573 <quote><literal>hg.serpentine.com</literal></quote> gives
bos@559 574 the hostname of the server to log into.</para>
bos@559 575 </listitem>
bos@584 576 <listitem><para id="x_48d">The <quote>:22</quote> identifies the port
bos@559 577 number to connect to the server on. The default port is
bos@579 578 22, so you only need to specify a colon and port number if
bos@579 579 you're <emphasis>not</emphasis> using port 22.</para>
bos@559 580 </listitem>
bos@584 581 <listitem><para id="x_48e">The remainder of the URL is the local path to
bos@559 582 the repository on the server.</para>
bos@559 583 </listitem></orderedlist>
bos@559 584
bos@584 585 <para id="x_48f">There's plenty of scope for confusion with the path
bos@559 586 component of ssh URLs, as there is no standard way for tools
bos@559 587 to interpret it. Some programs behave differently than others
bos@559 588 when dealing with these paths. This isn't an ideal situation,
bos@559 589 but it's unlikely to change. Please read the following
bos@559 590 paragraphs carefully.</para>
bos@559 591
bos@584 592 <para id="x_490">Mercurial treats the path to a repository on the server as
bos@559 593 relative to the remote user's home directory. For example, if
bos@559 594 user <literal>foo</literal> on the server has a home directory
bos@559 595 of <filename class="directory">/home/foo</filename>, then an
bos@559 596 ssh URL that contains a path component of <filename
bos@559 597 class="directory">bar</filename> <emphasis>really</emphasis>
bos@559 598 refers to the directory <filename
bos@559 599 class="directory">/home/foo/bar</filename>.</para>
bos@559 600
bos@584 601 <para id="x_491">If you want to specify a path relative to another user's
bos@559 602 home directory, you can use a path that starts with a tilde
bos@559 603 character followed by the user's name (let's call them
bos@559 604 <literal>otheruser</literal>), like this.</para>
bos@559 605 <programlisting>ssh://server/~otheruser/hg/repo</programlisting>
bos@559 606
bos@584 607 <para id="x_492">And if you really want to specify an
bos@559 608 <emphasis>absolute</emphasis> path on the server, begin the
bos@559 609 path component with two slashes, as in this example.</para>
bos@559 610 <programlisting>ssh://server//absolute/path</programlisting>
bos@675 611 </sect2>
bos@675 612
bos@559 613 <sect2>
bos@559 614 <title>Finding an ssh client for your system</title>
bos@559 615
bos@584 616 <para id="x_493">Almost every Unix-like system comes with OpenSSH
bos@559 617 preinstalled. If you're using such a system, run
bos@559 618 <literal>which ssh</literal> to find out if the
bos@559 619 <command>ssh</command> command is installed (it's usually in
bos@559 620 <filename class="directory">/usr/bin</filename>). In the
bos@559 621 unlikely event that it isn't present, take a look at your
bos@559 622 system documentation to figure out how to install it.</para>
bos@559 623
bos@675 624 <para id="x_494">On Windows, the TortoiseHg package is bundled
bos@675 625 with a version of Simon Tatham's excellent
bos@675 626 <command>plink</command> command, and you should not need to
bos@675 627 do any further configuration.</para>
bos@675 628 </sect2>
bos@675 629
bos@675 630 <sect2>
bos@675 631 <title>Generating a key pair</title>
bos@675 632
bos@675 633 <para id="x_499">To avoid the need to repetitively type a
bos@675 634 password every time you need to use your ssh client, I
bos@675 635 recommend generating a key pair.</para>
bos@675 636
bos@675 637 <tip>
bos@675 638 <title>Key pairs are not mandatory</title>
bos@675 639
bos@676 640 <para id="x_6a4">Mercurial knows nothing about ssh authentication or key
bos@675 641 pairs. You can, if you like, safely ignore this section and
bos@675 642 the one that follows until you grow tired of repeatedly
bos@675 643 typing ssh passwords.</para>
bos@675 644 </tip>
bos@675 645
bos@559 646 <itemizedlist>
bos@675 647 <listitem>
bos@676 648 <para id="x_6a5">On a Unix-like system, the
bos@675 649 <command>ssh-keygen</command> command will do the
bos@675 650 trick.</para>
bos@676 651 <para id="x_6a6">On Windows, if you're using TortoiseHg, you may need
bos@675 652 to download a command named <command>puttygen</command>
bos@675 653 from <ulink
bos@675 654 url="http://www.chiark.greenend.org.uk/~sgtatham/putty">the
bos@675 655 PuTTY web site</ulink> to generate a key pair. See
bos@675 656 <ulink
bos@675 657 url="http://the.earth.li/~sgtatham/putty/0.60/htmldoc/Chapter8.html#pubkey-puttygen">the
bos@675 658 <command>puttygen</command> documentation</ulink> for
bos@675 659 details of how use the command.</para>
bos@675 660 </listitem>
bos@675 661 </itemizedlist>
bos@559 662
bos@584 663 <para id="x_49a">When you generate a key pair, it's usually
bos@559 664 <emphasis>highly</emphasis> advisable to protect it with a
bos@559 665 passphrase. (The only time that you might not want to do this
bos@559 666 is when you're using the ssh protocol for automated tasks on a
bos@559 667 secure network.)</para>
bos@559 668
bos@584 669 <para id="x_49b">Simply generating a key pair isn't enough, however.
bos@559 670 You'll need to add the public key to the set of authorised
bos@559 671 keys for whatever user you're logging in remotely as. For
bos@559 672 servers using OpenSSH (the vast majority), this will mean
bos@559 673 adding the public key to a list in a file called <filename
bos@559 674 role="special">authorized_keys</filename> in their <filename
bos@559 675 role="special" class="directory">.ssh</filename>
bos@559 676 directory.</para>
bos@559 677
bos@584 678 <para id="x_49c">On a Unix-like system, your public key will have a
bos@559 679 <filename>.pub</filename> extension. If you're using
bos@559 680 <command>puttygen</command> on Windows, you can save the
bos@559 681 public key to a file of your choosing, or paste it from the
bos@559 682 window it's displayed in straight into the <filename
bos@559 683 role="special">authorized_keys</filename> file.</para>
bos@559 684 </sect2>
bos@559 685 <sect2>
bos@559 686 <title>Using an authentication agent</title>
bos@559 687
bos@584 688 <para id="x_49d">An authentication agent is a daemon that stores
bos@559 689 passphrases in memory (so it will forget passphrases if you
bos@559 690 log out and log back in again). An ssh client will notice if
bos@559 691 it's running, and query it for a passphrase. If there's no
bos@559 692 authentication agent running, or the agent doesn't store the
bos@559 693 necessary passphrase, you'll have to type your passphrase
bos@559 694 every time Mercurial tries to communicate with a server on
bos@559 695 your behalf (e.g. whenever you pull or push changes).</para>
bos@559 696
bos@584 697 <para id="x_49e">The downside of storing passphrases in an agent is that
bos@559 698 it's possible for a well-prepared attacker to recover the
bos@559 699 plain text of your passphrases, in some cases even if your
bos@559 700 system has been power-cycled. You should make your own
bos@559 701 judgment as to whether this is an acceptable risk. It
bos@559 702 certainly saves a lot of repeated typing.</para>
bos@559 703
bos@675 704 <itemizedlist>
bos@675 705 <listitem>
bos@675 706 <para id="x_49f">On Unix-like systems, the agent is called
bos@675 707 <command>ssh-agent</command>, and it's often run
bos@675 708 automatically for you when you log in. You'll need to use
bos@675 709 the <command>ssh-add</command> command to add passphrases
bos@675 710 to the agent's store.</para>
bos@675 711 </listitem>
bos@675 712 <listitem>
bos@676 713 <para id="x_6a7">On Windows, if you're using TortoiseHg, the
bos@675 714 <command>pageant</command> command acts as the agent. As
bos@675 715 with <command>puttygen</command>, you'll need to <ulink
bos@675 716 url="http://www.chiark.greenend.org.uk/%7Esgtatham/putty/download.html">download
bos@675 717 <command>pageant</command></ulink> from the PuTTY web
bos@675 718 site and read <ulink
bos@675 719 url="http://the.earth.li/~sgtatham/putty/0.60/htmldoc/Chapter9.html#pageant">its
bos@675 720 documentation</ulink>. The <command>pageant</command>
bos@675 721 command adds an icon to your system tray that will let you
bos@675 722 manage stored passphrases.</para>
bos@675 723 </listitem>
bos@675 724 </itemizedlist>
bos@675 725 </sect2>
bos@675 726
bos@559 727 <sect2>
bos@559 728 <title>Configuring the server side properly</title>
bos@559 729
bos@584 730 <para id="x_4a0">Because ssh can be fiddly to set up if you're new to it,
bos@675 731 a variety of things can go wrong. Add Mercurial
bos@559 732 on top, and there's plenty more scope for head-scratching.
bos@559 733 Most of these potential problems occur on the server side, not
bos@559 734 the client side. The good news is that once you've gotten a
bos@559 735 configuration working, it will usually continue to work
bos@559 736 indefinitely.</para>
bos@559 737
bos@584 738 <para id="x_4a1">Before you try using Mercurial to talk to an ssh server,
bos@559 739 it's best to make sure that you can use the normal
bos@559 740 <command>ssh</command> or <command>putty</command> command to
bos@559 741 talk to the server first. If you run into problems with using
bos@559 742 these commands directly, Mercurial surely won't work. Worse,
bos@559 743 it will obscure the underlying problem. Any time you want to
bos@559 744 debug ssh-related Mercurial problems, you should drop back to
bos@559 745 making sure that plain ssh client commands work first,
bos@559 746 <emphasis>before</emphasis> you worry about whether there's a
bos@559 747 problem with Mercurial.</para>
bos@559 748
bos@584 749 <para id="x_4a2">The first thing to be sure of on the server side is that
bos@559 750 you can actually log in from another machine at all. If you
bos@559 751 can't use <command>ssh</command> or <command>putty</command>
bos@559 752 to log in, the error message you get may give you a few hints
bos@559 753 as to what's wrong. The most common problems are as
bos@559 754 follows.</para>
bos@559 755 <itemizedlist>
bos@584 756 <listitem><para id="x_4a3">If you get a <quote>connection refused</quote>
bos@559 757 error, either there isn't an SSH daemon running on the
bos@559 758 server at all, or it's inaccessible due to firewall
bos@559 759 configuration.</para>
bos@559 760 </listitem>
bos@584 761 <listitem><para id="x_4a4">If you get a <quote>no route to host</quote>
bos@559 762 error, you either have an incorrect address for the server
bos@559 763 or a seriously locked down firewall that won't admit its
bos@559 764 existence at all.</para>
bos@559 765 </listitem>
bos@584 766 <listitem><para id="x_4a5">If you get a <quote>permission denied</quote>
bos@559 767 error, you may have mistyped the username on the server,
bos@559 768 or you could have mistyped your key's passphrase or the
bos@559 769 remote user's password.</para>
bos@559 770 </listitem></itemizedlist>
bos@584 771 <para id="x_4a6">In summary, if you're having trouble talking to the
bos@559 772 server's ssh daemon, first make sure that one is running at
bos@559 773 all. On many systems it will be installed, but disabled, by
bos@559 774 default. Once you're done with this step, you should then
bos@559 775 check that the server's firewall is configured to allow
bos@559 776 incoming connections on the port the ssh daemon is listening
bos@559 777 on (usually 22). Don't worry about more exotic possibilities
bos@559 778 for misconfiguration until you've checked these two
bos@559 779 first.</para>
bos@559 780
bos@584 781 <para id="x_4a7">If you're using an authentication agent on the client side
bos@559 782 to store passphrases for your keys, you ought to be able to
bos@559 783 log into the server without being prompted for a passphrase or
bos@559 784 a password. If you're prompted for a passphrase, there are a
bos@559 785 few possible culprits.</para>
bos@559 786 <itemizedlist>
bos@584 787 <listitem><para id="x_4a8">You might have forgotten to use
bos@559 788 <command>ssh-add</command> or <command>pageant</command>
bos@559 789 to store the passphrase.</para>
bos@559 790 </listitem>
bos@584 791 <listitem><para id="x_4a9">You might have stored the passphrase for the
bos@559 792 wrong key.</para>
bos@559 793 </listitem></itemizedlist>
bos@584 794 <para id="x_4aa">If you're being prompted for the remote user's password,
bos@559 795 there are another few possible problems to check.</para>
bos@559 796 <itemizedlist>
bos@584 797 <listitem><para id="x_4ab">Either the user's home directory or their
bos@559 798 <filename role="special" class="directory">.ssh</filename>
bos@559 799 directory might have excessively liberal permissions. As
bos@559 800 a result, the ssh daemon will not trust or read their
bos@559 801 <filename role="special">authorized_keys</filename> file.
bos@559 802 For example, a group-writable home or <filename
bos@559 803 role="special" class="directory">.ssh</filename>
bos@559 804 directory will often cause this symptom.</para>
bos@559 805 </listitem>
bos@584 806 <listitem><para id="x_4ac">The user's <filename
bos@559 807 role="special">authorized_keys</filename> file may have
bos@559 808 a problem. If anyone other than the user owns or can write
bos@559 809 to that file, the ssh daemon will not trust or read
bos@559 810 it.</para>
bos@559 811 </listitem></itemizedlist>
bos@559 812
bos@584 813 <para id="x_4ad">In the ideal world, you should be able to run the
bos@559 814 following command successfully, and it should print exactly
bos@559 815 one line of output, the current date and time.</para>
bos@559 816 <programlisting>ssh myserver date</programlisting>
bos@559 817
bos@584 818 <para id="x_4ae">If, on your server, you have login scripts that print
bos@559 819 banners or other junk even when running non-interactive
bos@559 820 commands like this, you should fix them before you continue,
bos@559 821 so that they only print output if they're run interactively.
bos@559 822 Otherwise these banners will at least clutter up Mercurial's
bos@559 823 output. Worse, they could potentially cause problems with
bos@701 824 running Mercurial commands remotely. Mercurial tries to
bos@559 825 detect and ignore banners in non-interactive
bos@559 826 <command>ssh</command> sessions, but it is not foolproof. (If
bos@559 827 you're editing your login scripts on your server, the usual
bos@559 828 way to see if a login script is running in an interactive
bos@559 829 shell is to check the return code from the command
bos@559 830 <literal>tty -s</literal>.)</para>
bos@559 831
bos@584 832 <para id="x_4af">Once you've verified that plain old ssh is working with
bos@559 833 your server, the next step is to ensure that Mercurial runs on
bos@559 834 the server. The following command should run
bos@559 835 successfully:</para>
bos@580 836
bos@559 837 <programlisting>ssh myserver hg version</programlisting>
bos@580 838
bos@584 839 <para id="x_4b0">If you see an error message instead of normal <command
bos@559 840 role="hg-cmd">hg version</command> output, this is usually
bos@559 841 because you haven't installed Mercurial to <filename
bos@559 842 class="directory">/usr/bin</filename>. Don't worry if this
bos@559 843 is the case; you don't need to do that. But you should check
bos@559 844 for a few possible problems.</para>
bos@559 845 <itemizedlist>
bos@584 846 <listitem><para id="x_4b1">Is Mercurial really installed on the server at
bos@559 847 all? I know this sounds trivial, but it's worth
bos@559 848 checking!</para>
bos@559 849 </listitem>
bos@584 850 <listitem><para id="x_4b2">Maybe your shell's search path (usually set
bos@559 851 via the <envar>PATH</envar> environment variable) is
bos@559 852 simply misconfigured.</para>
bos@559 853 </listitem>
bos@584 854 <listitem><para id="x_4b3">Perhaps your <envar>PATH</envar> environment
bos@559 855 variable is only being set to point to the location of the
bos@559 856 <command>hg</command> executable if the login session is
bos@559 857 interactive. This can happen if you're setting the path
bos@559 858 in the wrong shell login script. See your shell's
bos@559 859 documentation for details.</para>
bos@559 860 </listitem>
bos@584 861 <listitem><para id="x_4b4">The <envar>PYTHONPATH</envar> environment
bos@559 862 variable may need to contain the path to the Mercurial
bos@559 863 Python modules. It might not be set at all; it could be
bos@559 864 incorrect; or it may be set only if the login is
bos@559 865 interactive.</para>
bos@559 866 </listitem></itemizedlist>
bos@559 867
bos@584 868 <para id="x_4b5">If you can run <command role="hg-cmd">hg version</command>
bos@559 869 over an ssh connection, well done! You've got the server and
bos@559 870 client sorted out. You should now be able to use Mercurial to
bos@559 871 access repositories hosted by that username on that server.
bos@559 872 If you run into problems with Mercurial and ssh at this point,
bos@559 873 try using the <option role="hg-opt-global">--debug</option>
bos@559 874 option to get a clearer picture of what's going on.</para>
bos@559 875 </sect2>
bos@559 876 <sect2>
bos@559 877 <title>Using compression with ssh</title>
bos@559 878
bos@584 879 <para id="x_4b6">Mercurial does not compress data when it uses the ssh
bos@559 880 protocol, because the ssh protocol can transparently compress
bos@672 881 data. However, the default behavior of ssh clients is
bos@559 882 <emphasis>not</emphasis> to request compression.</para>
bos@559 883
bos@584 884 <para id="x_4b7">Over any network other than a fast LAN (even a wireless
bos@559 885 network), using compression is likely to significantly speed
bos@559 886 up Mercurial's network operations. For example, over a WAN,
bos@559 887 someone measured compression as reducing the amount of time
bos@559 888 required to clone a particularly large repository from 51
bos@559 889 minutes to 17 minutes.</para>
bos@559 890
bos@584 891 <para id="x_4b8">Both <command>ssh</command> and <command>plink</command>
bos@559 892 accept a <option role="cmd-opt-ssh">-C</option> option which
bos@559 893 turns on compression. You can easily edit your <filename
bos@580 894 role="special">~/.hgrc</filename> to enable compression for
bos@675 895 all of Mercurial's uses of the ssh protocol. Here is how to
bos@675 896 do so for regular <command>ssh</command> on Unix-like systems,
bos@675 897 for example.</para>
bos@579 898 <programlisting>[ui]
bos@579 899 ssh = ssh -C</programlisting>
bos@559 900
bos@675 901 <para id="x_4b9">If you use <command>ssh</command> on a
bos@675 902 Unix-like system, you can configure it to always use
bos@675 903 compression when talking to your server. To do this, edit
bos@675 904 your <filename role="special">.ssh/config</filename> file
bos@675 905 (which may not yet exist), as follows.</para>
bos@675 906
bos@579 907 <programlisting>Host hg
bos@579 908 Compression yes
bos@579 909 HostName hg.example.com</programlisting>
bos@675 910
bos@675 911 <para id="x_4ba">This defines a hostname alias,
bos@675 912 <literal>hg</literal>. When you use that hostname on the
bos@675 913 <command>ssh</command> command line or in a Mercurial
bos@675 914 <literal>ssh</literal>-protocol URL, it will cause
bos@559 915 <command>ssh</command> to connect to
bos@559 916 <literal>hg.example.com</literal> and use compression. This
bos@559 917 gives you both a shorter name to type and compression, each of
bos@559 918 which is a good thing in its own right.</para>
bos@559 919 </sect2>
bos@559 920 </sect1>
bos@675 921
bos@559 922 <sect1 id="sec:collab:cgi">
bos@559 923 <title>Serving over HTTP using CGI</title>
bos@559 924
bos@676 925 <para id="x_6a8">The simplest way to host one or more repositories in a
bos@675 926 permanent way is to use a web server and Mercurial's CGI
bos@675 927 support.</para>
bos@675 928
bos@584 929 <para id="x_4bb">Depending on how ambitious you are, configuring Mercurial's
bos@559 930 CGI interface can take anything from a few moments to several
bos@559 931 hours.</para>
bos@559 932
bos@584 933 <para id="x_4bc">We'll begin with the simplest of examples, and work our way
bos@559 934 towards a more complex configuration. Even for the most basic
bos@559 935 case, you're almost certainly going to need to read and modify
bos@559 936 your web server's configuration.</para>
bos@559 937
bos@559 938 <note>
bos@675 939 <title>High pain tolerance required</title>
bos@675 940
bos@675 941 <para id="x_4bd">Configuring a web server is a complex, fiddly,
bos@675 942 and highly system-dependent activity. I can't possibly give
bos@675 943 you instructions that will cover anything like all of the
bos@675 944 cases you will encounter. Please use your discretion and
bos@675 945 judgment in following the sections below. Be prepared to make
bos@675 946 plenty of mistakes, and to spend a lot of time reading your
bos@675 947 server's error logs.</para>
bos@675 948
bos@676 949 <para id="x_6a9">If you don't have a strong stomach for tweaking
bos@675 950 configurations over and over, or a compelling need to host
bos@675 951 your own services, you might want to try one of the public
bos@675 952 hosting services that I mentioned earlier.</para>
bos@559 953 </note>
bos@559 954
bos@559 955 <sect2>
bos@559 956 <title>Web server configuration checklist</title>
bos@559 957
bos@584 958 <para id="x_4be">Before you continue, do take a few moments to check a few
bos@559 959 aspects of your system's setup.</para>
bos@559 960
bos@559 961 <orderedlist>
bos@675 962 <listitem><para id="x_4bf">Do you have a web server installed
bos@675 963 at all? Mac OS X and some Linux distributions ship with
bos@675 964 Apache, but many other systems may not have a web server
bos@675 965 installed.</para>
bos@559 966 </listitem>
bos@584 967 <listitem><para id="x_4c0">If you have a web server installed, is it
bos@559 968 actually running? On most systems, even if one is
bos@559 969 present, it will be disabled by default.</para>
bos@559 970 </listitem>
bos@584 971 <listitem><para id="x_4c1">Is your server configured to allow you to run
bos@559 972 CGI programs in the directory where you plan to do so?
bos@559 973 Most servers default to explicitly disabling the ability
bos@559 974 to run CGI programs.</para>
bos@559 975 </listitem></orderedlist>
bos@559 976
bos@584 977 <para id="x_4c2">If you don't have a web server installed, and don't have
bos@559 978 substantial experience configuring Apache, you should consider
bos@559 979 using the <literal>lighttpd</literal> web server instead of
bos@559 980 Apache. Apache has a well-deserved reputation for baroque and
bos@559 981 confusing configuration. While <literal>lighttpd</literal> is
bos@559 982 less capable in some ways than Apache, most of these
bos@559 983 capabilities are not relevant to serving Mercurial
bos@559 984 repositories. And <literal>lighttpd</literal> is undeniably
bos@559 985 <emphasis>much</emphasis> easier to get started with than
bos@559 986 Apache.</para>
bos@675 987 </sect2>
bos@675 988
bos@559 989 <sect2>
bos@559 990 <title>Basic CGI configuration</title>
bos@559 991
bos@584 992 <para id="x_4c3">On Unix-like systems, it's common for users to have a
bos@559 993 subdirectory named something like <filename
bos@559 994 class="directory">public_html</filename> in their home
bos@559 995 directory, from which they can serve up web pages. A file
bos@559 996 named <filename>foo</filename> in this directory will be
bos@559 997 accessible at a URL of the form
bos@580 998 <literal>http://www.example.com/username/foo</literal>.</para>
bos@559 999
bos@584 1000 <para id="x_4c4">To get started, find the <filename
bos@559 1001 role="special">hgweb.cgi</filename> script that should be
bos@559 1002 present in your Mercurial installation. If you can't quickly
bos@559 1003 find a local copy on your system, simply download one from the
bos@559 1004 master Mercurial repository at <ulink
bos@559 1005 url="http://www.selenic.com/repo/hg/raw-file/tip/hgweb.cgi">http://www.selenic.com/repo/hg/raw-file/tip/hgweb.cgi</ulink>.</para>
bos@559 1006
bos@584 1007 <para id="x_4c5">You'll need to copy this script into your <filename
bos@559 1008 class="directory">public_html</filename> directory, and
bos@559 1009 ensure that it's executable.</para>
bos@579 1010 <programlisting>cp .../hgweb.cgi ~/public_html
bos@579 1011 chmod 755 ~/public_html/hgweb.cgi</programlisting>
bos@584 1012 <para id="x_4c6">The <literal>755</literal> argument to
bos@559 1013 <command>chmod</command> is a little more general than just
bos@559 1014 making the script executable: it ensures that the script is
bos@559 1015 executable by anyone, and that <quote>group</quote> and
bos@559 1016 <quote>other</quote> write permissions are
bos@559 1017 <emphasis>not</emphasis> set. If you were to leave those
bos@559 1018 write permissions enabled, Apache's <literal>suexec</literal>
bos@559 1019 subsystem would likely refuse to execute the script. In fact,
bos@559 1020 <literal>suexec</literal> also insists that the
bos@559 1021 <emphasis>directory</emphasis> in which the script resides
bos@559 1022 must not be writable by others.</para>
bos@559 1023 <programlisting>chmod 755 ~/public_html</programlisting>
bos@559 1024
bos@559 1025 <sect3 id="sec:collab:wtf">
bos@559 1026 <title>What could <emphasis>possibly</emphasis> go
bos@559 1027 wrong?</title>
bos@559 1028
hg@677 1029 <para id="x_4c7">Once you've copied the CGI script into place,
bos@679 1030 go into a web browser, and try to open the URL
bos@679 1031 <literal>http://myhostname/~myuser/hgweb.cgi</literal>,
bos@679 1032 <emphasis>but</emphasis> brace yourself for instant failure.
bos@679 1033 There's a high probability that trying to visit this URL
bos@679 1034 will fail, and there are many possible reasons for this. In
bos@679 1035 fact, you're likely to stumble over almost every one of the
bos@679 1036 possible errors below, so please read carefully. The
bos@679 1037 following are all of the problems I ran into on a system
bos@679 1038 running Fedora 7, with a fresh installation of Apache, and a
bos@679 1039 user account that I created specially to perform this
bos@679 1040 exercise.</para>
bos@559 1041
bos@584 1042 <para id="x_4c8">Your web server may have per-user directories disabled.
bos@559 1043 If you're using Apache, search your config file for a
bos@559 1044 <literal>UserDir</literal> directive. If there's none
bos@559 1045 present, per-user directories will be disabled. If one
bos@559 1046 exists, but its value is <literal>disabled</literal>, then
bos@559 1047 per-user directories will be disabled. Otherwise, the
bos@559 1048 string after <literal>UserDir</literal> gives the name of
bos@559 1049 the subdirectory that Apache will look in under your home
bos@559 1050 directory, for example <filename
bos@559 1051 class="directory">public_html</filename>.</para>
bos@559 1052
bos@584 1053 <para id="x_4c9">Your file access permissions may be too restrictive.
bos@559 1054 The web server must be able to traverse your home directory
bos@559 1055 and directories under your <filename
bos@559 1056 class="directory">public_html</filename> directory, and
bos@559 1057 read files under the latter too. Here's a quick recipe to
bos@559 1058 help you to make your permissions more appropriate.</para>
bos@579 1059 <programlisting>chmod 755 ~
bos@579 1060 find ~/public_html -type d -print0 | xargs -0r chmod 755
bos@579 1061 find ~/public_html -type f -print0 | xargs -0r chmod 644</programlisting>
bos@559 1062
bos@584 1063 <para id="x_4ca">The other possibility with permissions is that you might
bos@559 1064 get a completely empty window when you try to load the
bos@559 1065 script. In this case, it's likely that your access
ori@561 1066 permissions are <emphasis>too permissive</emphasis>. Apache's
bos@559 1067 <literal>suexec</literal> subsystem won't execute a script
bos@559 1068 that's group- or world-writable, for example.</para>
bos@559 1069
bos@584 1070 <para id="x_4cb">Your web server may be configured to disallow execution
bos@559 1071 of CGI programs in your per-user web directory. Here's
bos@559 1072 Apache's default per-user configuration from my Fedora
bos@559 1073 system.</para>
bos@579 1074
bos@579 1075 &ch06-apache-config.lst;
bos@579 1076
bos@584 1077 <para id="x_4cc">If you find a similar-looking
bos@559 1078 <literal>Directory</literal> group in your Apache
bos@559 1079 configuration, the directive to look at inside it is
bos@559 1080 <literal>Options</literal>. Add <literal>ExecCGI</literal>
bos@559 1081 to the end of this list if it's missing, and restart the web
bos@559 1082 server.</para>
bos@559 1083
bos@584 1084 <para id="x_4cd">If you find that Apache serves you the text of the CGI
bos@559 1085 script instead of executing it, you may need to either
bos@559 1086 uncomment (if already present) or add a directive like
bos@559 1087 this.</para>
bos@559 1088 <programlisting>AddHandler cgi-script .cgi</programlisting>
bos@559 1089
bos@584 1090 <para id="x_4ce">The next possibility is that you might be served with a
bos@559 1091 colourful Python backtrace claiming that it can't import a
bos@559 1092 <literal>mercurial</literal>-related module. This is
bos@559 1093 actually progress! The server is now capable of executing
bos@559 1094 your CGI script. This error is only likely to occur if
bos@559 1095 you're running a private installation of Mercurial, instead
bos@559 1096 of a system-wide version. Remember that the web server runs
bos@559 1097 the CGI program without any of the environment variables
bos@559 1098 that you take for granted in an interactive session. If
bos@559 1099 this error happens to you, edit your copy of <filename
bos@559 1100 role="special">hgweb.cgi</filename> and follow the
bos@559 1101 directions inside it to correctly set your
bos@559 1102 <envar>PYTHONPATH</envar> environment variable.</para>
bos@559 1103
bos@701 1104 <para id="x_4cf">Finally, you are <emphasis>certain</emphasis> to be
bos@559 1105 served with another colourful Python backtrace: this one
bos@559 1106 will complain that it can't find <filename
bos@559 1107 class="directory">/path/to/repository</filename>. Edit
bos@559 1108 your <filename role="special">hgweb.cgi</filename> script
bos@559 1109 and replace the <filename
bos@559 1110 class="directory">/path/to/repository</filename> string
bos@559 1111 with the complete path to the repository you want to serve
bos@559 1112 up.</para>
bos@559 1113
bos@584 1114 <para id="x_4d0">At this point, when you try to reload the page, you
bos@559 1115 should be presented with a nice HTML view of your
bos@559 1116 repository's history. Whew!</para>
bos@559 1117 </sect3>
bos@675 1118
bos@559 1119 <sect3>
bos@559 1120 <title>Configuring lighttpd</title>
bos@559 1121
bos@584 1122 <para id="x_4d1">To be exhaustive in my experiments, I tried configuring
bos@559 1123 the increasingly popular <literal>lighttpd</literal> web
bos@559 1124 server to serve the same repository as I described with
bos@559 1125 Apache above. I had already overcome all of the problems I
bos@559 1126 outlined with Apache, many of which are not server-specific.
bos@559 1127 As a result, I was fairly sure that my file and directory
bos@559 1128 permissions were good, and that my <filename
bos@559 1129 role="special">hgweb.cgi</filename> script was properly
bos@559 1130 edited.</para>
bos@559 1131
bos@584 1132 <para id="x_4d2">Once I had Apache running, getting
bos@559 1133 <literal>lighttpd</literal> to serve the repository was a
bos@559 1134 snap (in other words, even if you're trying to use
bos@559 1135 <literal>lighttpd</literal>, you should read the Apache
bos@559 1136 section). I first had to edit the
bos@559 1137 <literal>mod_access</literal> section of its config file to
bos@559 1138 enable <literal>mod_cgi</literal> and
bos@559 1139 <literal>mod_userdir</literal>, both of which were disabled
bos@559 1140 by default on my system. I then added a few lines to the
bos@559 1141 end of the config file, to configure these modules.</para>
bos@580 1142 <programlisting>userdir.path = "public_html"
bos@580 1143 cgi.assign = (".cgi" =&gt; "" )</programlisting>
bos@584 1144 <para id="x_4d3">With this done, <literal>lighttpd</literal> ran
bos@559 1145 immediately for me. If I had configured
bos@559 1146 <literal>lighttpd</literal> before Apache, I'd almost
bos@559 1147 certainly have run into many of the same system-level
bos@559 1148 configuration problems as I did with Apache. However, I
bos@559 1149 found <literal>lighttpd</literal> to be noticeably easier to
bos@559 1150 configure than Apache, even though I've used Apache for over
bos@559 1151 a decade, and this was my first exposure to
bos@559 1152 <literal>lighttpd</literal>.</para>
bos@559 1153 </sect3>
bos@559 1154 </sect2>
bos@675 1155
bos@559 1156 <sect2>
bos@559 1157 <title>Sharing multiple repositories with one CGI script</title>
bos@559 1158
bos@584 1159 <para id="x_4d4">The <filename role="special">hgweb.cgi</filename> script
bos@559 1160 only lets you publish a single repository, which is an
bos@559 1161 annoying restriction. If you want to publish more than one
bos@559 1162 without wracking yourself with multiple copies of the same
bos@559 1163 script, each with different names, a better choice is to use
bos@559 1164 the <filename role="special">hgwebdir.cgi</filename>
bos@559 1165 script.</para>
bos@559 1166
bos@584 1167 <para id="x_4d5">The procedure to configure <filename
bos@559 1168 role="special">hgwebdir.cgi</filename> is only a little more
bos@559 1169 involved than for <filename
bos@559 1170 role="special">hgweb.cgi</filename>. First, you must obtain
bos@559 1171 a copy of the script. If you don't have one handy, you can
bos@559 1172 download a copy from the master Mercurial repository at <ulink
bos@559 1173 url="http://www.selenic.com/repo/hg/raw-file/tip/hgwebdir.cgi">http://www.selenic.com/repo/hg/raw-file/tip/hgwebdir.cgi</ulink>.</para>
bos@559 1174
bos@584 1175 <para id="x_4d6">You'll need to copy this script into your <filename
bos@559 1176 class="directory">public_html</filename> directory, and
bos@559 1177 ensure that it's executable.</para>
bos@592 1178
bos@580 1179 <programlisting>cp .../hgwebdir.cgi ~/public_html
bos@580 1180 chmod 755 ~/public_html ~/public_html/hgwebdir.cgi</programlisting>
bos@592 1181
bos@592 1182 <para id="x_4d7">With basic configuration out of the way, try to
bos@679 1183 visit <literal>http://myhostname/~myuser/hgwebdir.cgi</literal>
hg@677 1184 in your browser. It should
bos@559 1185 display an empty list of repositories. If you get a blank
bos@559 1186 window or error message, try walking through the list of
bos@592 1187 potential problems in <xref
bos@559 1188 linkend="sec:collab:wtf"/>.</para>
bos@559 1189
bos@584 1190 <para id="x_4d8">The <filename role="special">hgwebdir.cgi</filename>
bos@559 1191 script relies on an external configuration file. By default,
bos@559 1192 it searches for a file named <filename
bos@559 1193 role="special">hgweb.config</filename> in the same directory
bos@559 1194 as itself. You'll need to create this file, and make it
bos@559 1195 world-readable. The format of the file is similar to a
bos@559 1196 Windows <quote>ini</quote> file, as understood by Python's
bos@559 1197 <literal>ConfigParser</literal>
bos@559 1198 <citation>web:configparser</citation> module.</para>
bos@559 1199
bos@584 1200 <para id="x_4d9">The easiest way to configure <filename
bos@559 1201 role="special">hgwebdir.cgi</filename> is with a section
bos@559 1202 named <literal>collections</literal>. This will automatically
bos@559 1203 publish <emphasis>every</emphasis> repository under the
bos@559 1204 directories you name. The section should look like
bos@559 1205 this:</para>
bos@580 1206 <programlisting>[collections]
bos@580 1207 /my/root = /my/root</programlisting>
bos@584 1208 <para id="x_4da">Mercurial interprets this by looking at the directory name
bos@559 1209 on the <emphasis>right</emphasis> hand side of the
bos@559 1210 <quote><literal>=</literal></quote> sign; finding repositories
bos@559 1211 in that directory hierarchy; and using the text on the
bos@559 1212 <emphasis>left</emphasis> to strip off matching text from the
bos@559 1213 names it will actually list in the web interface. The
bos@559 1214 remaining component of a path after this stripping has
bos@559 1215 occurred is called a <quote>virtual path</quote>.</para>
bos@559 1216
bos@679 1217 <para id="x_4db">Given the example above, if we have a
bos@679 1218 repository whose local path is <filename
bos@559 1219 class="directory">/my/root/this/repo</filename>, the CGI
bos@559 1220 script will strip the leading <filename
bos@559 1221 class="directory">/my/root</filename> from the name, and
bos@559 1222 publish the repository with a virtual path of <filename
bos@559 1223 class="directory">this/repo</filename>. If the base URL for
bos@679 1224 our CGI script is
bos@679 1225 <literal>http://myhostname/~myuser/hgwebdir.cgi</literal>, the
bos@679 1226 complete URL for that repository will be
bos@679 1227 <literal>http://myhostname/~myuser/hgwebdir.cgi/this/repo</literal>.</para>
bos@559 1228
bos@584 1229 <para id="x_4dc">If we replace <filename
bos@559 1230 class="directory">/my/root</filename> on the left hand side
bos@559 1231 of this example with <filename
bos@559 1232 class="directory">/my</filename>, then <filename
bos@559 1233 role="special">hgwebdir.cgi</filename> will only strip off
bos@559 1234 <filename class="directory">/my</filename> from the repository
bos@559 1235 name, and will give us a virtual path of <filename
bos@559 1236 class="directory">root/this/repo</filename> instead of
bos@559 1237 <filename class="directory">this/repo</filename>.</para>
bos@559 1238
bos@584 1239 <para id="x_4dd">The <filename role="special">hgwebdir.cgi</filename>
bos@559 1240 script will recursively search each directory listed in the
bos@559 1241 <literal>collections</literal> section of its configuration
bos@559 1242 file, but it will <literal>not</literal> recurse into the
bos@559 1243 repositories it finds.</para>
bos@559 1244
bos@584 1245 <para id="x_4de">The <literal>collections</literal> mechanism makes it easy
bos@559 1246 to publish many repositories in a <quote>fire and
bos@559 1247 forget</quote> manner. You only need to set up the CGI
bos@559 1248 script and configuration file one time. Afterwards, you can
bos@559 1249 publish or unpublish a repository at any time by simply moving
bos@559 1250 it into, or out of, the directory hierarchy in which you've
bos@559 1251 configured <filename role="special">hgwebdir.cgi</filename> to
bos@559 1252 look.</para>
bos@559 1253
bos@559 1254 <sect3>
bos@559 1255 <title>Explicitly specifying which repositories to
bos@559 1256 publish</title>
bos@559 1257
bos@584 1258 <para id="x_4df">In addition to the <literal>collections</literal>
bos@559 1259 mechanism, the <filename
bos@559 1260 role="special">hgwebdir.cgi</filename> script allows you
bos@559 1261 to publish a specific list of repositories. To do so,
bos@559 1262 create a <literal>paths</literal> section, with contents of
bos@559 1263 the following form.</para>
bos@580 1264 <programlisting>[paths]
bos@580 1265 repo1 = /my/path/to/some/repo
bos@580 1266 repo2 = /some/path/to/another</programlisting>
bos@584 1267 <para id="x_4e0">In this case, the virtual path (the component that will
bos@559 1268 appear in a URL) is on the left hand side of each
bos@559 1269 definition, while the path to the repository is on the
bos@559 1270 right. Notice that there does not need to be any
bos@559 1271 relationship between the virtual path you choose and the
bos@559 1272 location of a repository in your filesystem.</para>
bos@559 1273
bos@584 1274 <para id="x_4e1">If you wish, you can use both the
bos@559 1275 <literal>collections</literal> and <literal>paths</literal>
bos@559 1276 mechanisms simultaneously in a single configuration
bos@559 1277 file.</para>
bos@559 1278
bos@559 1279 <note>
bos@675 1280 <title>Beware duplicate virtual paths</title>
bos@675 1281
bos@675 1282 <para id="x_4e2"> If several repositories have the same
bos@675 1283 virtual path, <filename
bos@675 1284 role="special">hgwebdir.cgi</filename> will not report
bos@675 1285 an error. Instead, it will behave unpredictably.</para>
bos@559 1286 </note>
bos@559 1287 </sect3>
bos@559 1288 </sect2>
bos@675 1289
bos@559 1290 <sect2>
bos@559 1291 <title>Downloading source archives</title>
bos@559 1292
bos@584 1293 <para id="x_4e3">Mercurial's web interface lets users download an archive
bos@559 1294 of any revision. This archive will contain a snapshot of the
bos@559 1295 working directory as of that revision, but it will not contain
bos@559 1296 a copy of the repository data.</para>
bos@559 1297
bos@584 1298 <para id="x_4e4">By default, this feature is not enabled. To enable it,
bos@559 1299 you'll need to add an <envar
bos@559 1300 role="rc-item-web">allow_archive</envar> item to the
bos@559 1301 <literal role="rc-web">web</literal> section of your <filename
bos@675 1302 role="special">~/.hgrc</filename>; see below for details.</para>
bos@559 1303 </sect2>
bos@559 1304 <sect2>
bos@559 1305 <title>Web configuration options</title>
bos@559 1306
bos@584 1307 <para id="x_4e5">Mercurial's web interfaces (the <command role="hg-cmd">hg
bos@559 1308 serve</command> command, and the <filename
bos@559 1309 role="special">hgweb.cgi</filename> and <filename
bos@559 1310 role="special">hgwebdir.cgi</filename> scripts) have a
bos@559 1311 number of configuration options that you can set. These
bos@559 1312 belong in a section named <literal
bos@559 1313 role="rc-web">web</literal>.</para>
bos@559 1314 <itemizedlist>
bos@584 1315 <listitem><para id="x_4e6"><envar
bos@559 1316 role="rc-item-web">allow_archive</envar>: Determines
bos@559 1317 which (if any) archive download mechanisms Mercurial
bos@559 1318 supports. If you enable this feature, users of the web
bos@559 1319 interface will be able to download an archive of whatever
bos@559 1320 revision of a repository they are viewing. To enable the
bos@559 1321 archive feature, this item must take the form of a
bos@559 1322 sequence of words drawn from the list below.</para>
bos@559 1323 <itemizedlist>
bos@584 1324 <listitem><para id="x_4e7"><literal>bz2</literal>: A
bos@559 1325 <command>tar</command> archive, compressed using
bos@559 1326 <literal>bzip2</literal> compression. This has the
bos@559 1327 best compression ratio, but uses the most CPU time on
bos@559 1328 the server.</para>
bos@559 1329 </listitem>
bos@584 1330 <listitem><para id="x_4e8"><literal>gz</literal>: A
bos@559 1331 <command>tar</command> archive, compressed using
bos@559 1332 <literal>gzip</literal> compression.</para>
bos@559 1333 </listitem>
bos@584 1334 <listitem><para id="x_4e9"><literal>zip</literal>: A
bos@559 1335 <command>zip</command> archive, compressed using LZW
bos@559 1336 compression. This format has the worst compression
bos@559 1337 ratio, but is widely used in the Windows world.</para>
bos@559 1338 </listitem>
bos@559 1339 </itemizedlist>
bos@584 1340 <para id="x_4ea"> If you provide an empty list, or don't have an
bos@559 1341 <envar role="rc-item-web">allow_archive</envar> entry at
bos@559 1342 all, this feature will be disabled. Here is an example of
bos@559 1343 how to enable all three supported formats.</para>
bos@580 1344 <programlisting>[web]
bos@580 1345 allow_archive = bz2 gz zip</programlisting>
bos@559 1346 </listitem>
bos@584 1347 <listitem><para id="x_4eb"><envar role="rc-item-web">allowpull</envar>:
bos@559 1348 Boolean. Determines whether the web interface allows
bos@559 1349 remote users to <command role="hg-cmd">hg pull</command>
bos@559 1350 and <command role="hg-cmd">hg clone</command> this
bos@559 1351 repository over HTTP. If set to <literal>no</literal> or
bos@559 1352 <literal>false</literal>, only the
bos@559 1353 <quote>human-oriented</quote> portion of the web interface
bos@559 1354 is available.</para>
bos@559 1355 </listitem>
bos@584 1356 <listitem><para id="x_4ec"><envar role="rc-item-web">contact</envar>:
bos@559 1357 String. A free-form (but preferably brief) string
bos@559 1358 identifying the person or group in charge of the
bos@559 1359 repository. This often contains the name and email
bos@559 1360 address of a person or mailing list. It often makes sense
bos@559 1361 to place this entry in a repository's own <filename
bos@559 1362 role="special">.hg/hgrc</filename> file, but it can make
bos@580 1363 sense to use in a global <filename
bos@580 1364 role="special">~/.hgrc</filename> if every repository
bos@580 1365 has a single maintainer.</para>
bos@559 1366 </listitem>
bos@584 1367 <listitem><para id="x_4ed"><envar role="rc-item-web">maxchanges</envar>:
bos@559 1368 Integer. The default maximum number of changesets to
bos@559 1369 display in a single page of output.</para>
bos@559 1370 </listitem>
bos@584 1371 <listitem><para id="x_4ee"><envar role="rc-item-web">maxfiles</envar>:
bos@559 1372 Integer. The default maximum number of modified files to
bos@559 1373 display in a single page of output.</para>
bos@559 1374 </listitem>
bos@584 1375 <listitem><para id="x_4ef"><envar role="rc-item-web">stripes</envar>:
bos@559 1376 Integer. If the web interface displays alternating
bos@559 1377 <quote>stripes</quote> to make it easier to visually align
bos@559 1378 rows when you are looking at a table, this number controls
bos@559 1379 the number of rows in each stripe.</para>
bos@559 1380 </listitem>
bos@592 1381 <listitem><para id="x_4f0"><envar
bos@592 1382 role="rc-item-web">style</envar>: Controls the template
bos@592 1383 Mercurial uses to display the web interface. Mercurial
bos@675 1384 ships with several web templates.</para>
bos@675 1385 <itemizedlist>
bos@675 1386 <listitem>
bos@676 1387 <para id="x_6aa"><literal>coal</literal> is monochromatic.</para>
bos@675 1388 </listitem>
bos@675 1389 <listitem>
bos@676 1390 <para id="x_6ab"><literal>gitweb</literal> emulates the visual
bos@675 1391 style of git's web interface.</para>
bos@675 1392 </listitem>
bos@675 1393 <listitem>
bos@676 1394 <para id="x_6ac"><literal>monoblue</literal> uses solid blues and
bos@675 1395 greys.</para>
bos@675 1396 </listitem>
bos@675 1397 <listitem>
bos@676 1398 <para id="x_6ad"><literal>paper</literal> is the default.</para>
bos@675 1399 </listitem>
bos@675 1400 <listitem>
bos@676 1401 <para id="x_6ae"><literal>spartan</literal> was the default for a
bos@675 1402 long time.</para>
bos@675 1403 </listitem>
bos@675 1404 </itemizedlist>
bos@676 1405 <para id="x_6af">You can
bos@592 1406 also specify a custom template of your own; see
bos@592 1407 <xref linkend="chap:template"/> for details. Here, you can
bos@592 1408 see how to enable the <literal>gitweb</literal>
bos@592 1409 style.</para>
bos@580 1410 <programlisting>[web]
bos@580 1411 style = gitweb</programlisting>
bos@559 1412 </listitem>
bos@584 1413 <listitem><para id="x_4f1"><envar role="rc-item-web">templates</envar>:
bos@559 1414 Path. The directory in which to search for template
bos@559 1415 files. By default, Mercurial searches in the directory in
bos@559 1416 which it was installed.</para>
bos@559 1417 </listitem></itemizedlist>
bos@584 1418 <para id="x_4f2">If you are using <filename
bos@559 1419 role="special">hgwebdir.cgi</filename>, you can place a few
bos@559 1420 configuration items in a <literal role="rc-web">web</literal>
bos@559 1421 section of the <filename
bos@559 1422 role="special">hgweb.config</filename> file instead of a
bos@580 1423 <filename role="special">~/.hgrc</filename> file, for
bos@559 1424 convenience. These items are <envar
bos@559 1425 role="rc-item-web">motd</envar> and <envar
bos@559 1426 role="rc-item-web">style</envar>.</para>
bos@559 1427
bos@559 1428 <sect3>
bos@559 1429 <title>Options specific to an individual repository</title>
bos@559 1430
bos@584 1431 <para id="x_4f3">A few <literal role="rc-web">web</literal> configuration
bos@559 1432 items ought to be placed in a repository's local <filename
bos@559 1433 role="special">.hg/hgrc</filename>, rather than a user's
bos@580 1434 or global <filename role="special">~/.hgrc</filename>.</para>
bos@559 1435 <itemizedlist>
bos@584 1436 <listitem><para id="x_4f4"><envar
bos@559 1437 role="rc-item-web">description</envar>: String. A
bos@559 1438 free-form (but preferably brief) string that describes
bos@559 1439 the contents or purpose of the repository.</para>
bos@559 1440 </listitem>
bos@584 1441 <listitem><para id="x_4f5"><envar role="rc-item-web">name</envar>:
bos@559 1442 String. The name to use for the repository in the web
bos@559 1443 interface. This overrides the default name, which is
bos@559 1444 the last component of the repository's path.</para>
bos@559 1445 </listitem></itemizedlist>
bos@559 1446 </sect3>
bos@675 1447
bos@559 1448 <sect3>
bos@559 1449 <title>Options specific to the <command role="hg-cmd">hg
bos@559 1450 serve</command> command</title>
bos@559 1451
bos@584 1452 <para id="x_4f6">Some of the items in the <literal
bos@559 1453 role="rc-web">web</literal> section of a <filename
bos@580 1454 role="special">~/.hgrc</filename> file are only for use
bos@559 1455 with the <command role="hg-cmd">hg serve</command>
bos@559 1456 command.</para>
bos@559 1457 <itemizedlist>
bos@584 1458 <listitem><para id="x_4f7"><envar role="rc-item-web">accesslog</envar>:
bos@559 1459 Path. The name of a file into which to write an access
bos@559 1460 log. By default, the <command role="hg-cmd">hg
bos@559 1461 serve</command> command writes this information to
bos@559 1462 standard output, not to a file. Log entries are written
bos@559 1463 in the standard <quote>combined</quote> file format used
bos@559 1464 by almost all web servers.</para>
bos@559 1465 </listitem>
bos@584 1466 <listitem><para id="x_4f8"><envar role="rc-item-web">address</envar>:
bos@559 1467 String. The local address on which the server should
bos@559 1468 listen for incoming connections. By default, the server
bos@559 1469 listens on all addresses.</para>
bos@559 1470 </listitem>
bos@584 1471 <listitem><para id="x_4f9"><envar role="rc-item-web">errorlog</envar>:
bos@559 1472 Path. The name of a file into which to write an error
bos@559 1473 log. By default, the <command role="hg-cmd">hg
bos@559 1474 serve</command> command writes this information to
bos@559 1475 standard error, not to a file.</para>
bos@559 1476 </listitem>
bos@584 1477 <listitem><para id="x_4fa"><envar role="rc-item-web">ipv6</envar>:
bos@559 1478 Boolean. Whether to use the IPv6 protocol. By default,
bos@559 1479 IPv6 is not used.</para>
bos@559 1480 </listitem>
bos@584 1481 <listitem><para id="x_4fb"><envar role="rc-item-web">port</envar>:
bos@559 1482 Integer. The TCP port number on which the server should
bos@559 1483 listen. The default port number used is 8000.</para>
bos@559 1484 </listitem></itemizedlist>
bos@559 1485 </sect3>
bos@675 1486
bos@559 1487 <sect3>
bos@580 1488 <title>Choosing the right <filename
bos@580 1489 role="special">~/.hgrc</filename> file to add <literal
bos@559 1490 role="rc-web">web</literal> items to</title>
bos@559 1491
bos@584 1492 <para id="x_4fc">It is important to remember that a web server like
bos@559 1493 Apache or <literal>lighttpd</literal> will run under a user
bos@559 1494 ID that is different to yours. CGI scripts run by your
bos@559 1495 server, such as <filename
bos@559 1496 role="special">hgweb.cgi</filename>, will usually also run
bos@559 1497 under that user ID.</para>
bos@559 1498
bos@584 1499 <para id="x_4fd">If you add <literal role="rc-web">web</literal> items to
bos@580 1500 your own personal <filename role="special">~/.hgrc</filename> file, CGI scripts won't read that
bos@580 1501 <filename role="special">~/.hgrc</filename> file. Those
bos@672 1502 settings will thus only affect the behavior of the <command
bos@559 1503 role="hg-cmd">hg serve</command> command when you run it.
bos@559 1504 To cause CGI scripts to see your settings, either create a
bos@580 1505 <filename role="special">~/.hgrc</filename> file in the
bos@559 1506 home directory of the user ID that runs your web server, or
bos@559 1507 add those settings to a system-wide <filename
bos@675 1508 role="special">hgrc</filename> file.</para>
bos@559 1509 </sect3>
bos@559 1510 </sect2>
bos@559 1511 </sect1>
bos@675 1512
bos@675 1513 <sect1>
bos@675 1514 <title>System-wide configuration</title>
bos@675 1515
bos@676 1516 <para id="x_6b0">On Unix-like systems shared by multiple users (such as a
bos@675 1517 server to which people publish changes), it often makes sense to
bos@675 1518 set up some global default behaviors, such as what theme to use
bos@675 1519 in web interfaces.</para>
bos@675 1520
bos@676 1521 <para id="x_6b1">If a file named <filename>/etc/mercurial/hgrc</filename>
bos@675 1522 exists, Mercurial will read it at startup time and apply any
bos@675 1523 configuration settings it finds in that file. It will also look
bos@675 1524 for files ending in a <literal>.rc</literal> extension in a
bos@675 1525 directory named <filename>/etc/mercurial/hgrc.d</filename>, and
bos@675 1526 apply any configuration settings it finds in each of those
bos@675 1527 files.</para>
bos@675 1528
bos@675 1529 <sect2>
bos@675 1530 <title>Making Mercurial more trusting</title>
bos@675 1531
bos@676 1532 <para id="x_6b2">One situation in which a global <filename>hgrc</filename>
bos@675 1533 can be useful is if users are pulling changes owned by other
bos@675 1534 users. By default, Mercurial will not trust most of the
bos@675 1535 configuration items in a <filename>.hg/hgrc</filename> file
bos@675 1536 inside a repository that is owned by a different user. If we
bos@675 1537 clone or pull changes from such a repository, Mercurial will
bos@675 1538 print a warning stating that it does not trust their
bos@675 1539 <filename>.hg/hgrc</filename>.</para>
bos@675 1540
bos@676 1541 <para id="x_6b3">If everyone in a particular Unix group is on the same team
bos@675 1542 and <emphasis>should</emphasis> trust each other's
bos@675 1543 configuration settings, or we want to trust particular users,
bos@675 1544 we can override Mercurial's skeptical defaults by creating a
bos@675 1545 system-wide <filename>hgrc</filename> file such as the
bos@675 1546 following:</para>
bos@675 1547
bos@675 1548 <programlisting># Save this as e.g. /etc/mercurial/hgrc.d/trust.rc
bos@675 1549 [trusted]
bos@675 1550 # Trust all entries in any hgrc file owned by the "editors" or
bos@675 1551 # "www-data" groups.
bos@675 1552 groups = editors, www-data
bos@675 1553
bos@675 1554 # Trust entries in hgrc files owned by the following users.
bos@675 1555 users = apache, bobo
bos@675 1556 </programlisting>
bos@675 1557 </sect2>
bos@675 1558 </sect1>
bos@559 1559 </chapter>
bos@559 1560
bos@559 1561 <!--
bos@559 1562 local variables:
bos@559 1563 sgml-parent-document: ("00book.xml" "book" "chapter")
bos@559 1564 end:
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