hgbook

annotate en/ch05-collab.xml @ 591:b788b405e141

Replace uses of <informalfigure> with <figure>
author Bryan O'Sullivan <bos@serpentine.com>
date Thu Mar 26 21:07:39 2009 -0700 (2009-03-26)
parents c838b3975bc6
children 4ce9d0754af3
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@559 22 diffs), and view the contents of each directory and file.</para>
bos@559 23
bos@584 24 <para id="x_44d">Also for human consumption, the web interface provides an
bos@559 25 RSS feed of the changes in a repository. This lets you
bos@559 26 <quote>subscribe</quote> to a repository using your favourite
bos@559 27 feed reader, and be automatically notified of activity in that
bos@559 28 repository as soon as it happens. I find this capability much
bos@559 29 more convenient than the model of subscribing to a mailing list
bos@559 30 to which notifications are sent, as it requires no additional
bos@559 31 configuration on the part of whoever is serving the
bos@559 32 repository.</para>
bos@559 33
bos@584 34 <para id="x_44e">The web interface also lets remote users clone a repository,
bos@559 35 pull changes from it, and (when the server is configured to
bos@559 36 permit it) push changes back to it. Mercurial's HTTP tunneling
bos@559 37 protocol aggressively compresses data, so that it works
bos@559 38 efficiently even over low-bandwidth network connections.</para>
bos@559 39
bos@584 40 <para id="x_44f">The easiest way to get started with the web interface is to
bos@559 41 use your web browser to visit an existing repository, such as
bos@559 42 the master Mercurial repository at <ulink
bos@559 43 url="http://www.selenic.com/repo/hg?style=gitweb">http://www.selenic.com/repo/hg?style=gitweb</ulink>.</para>
bos@559 44
bos@584 45 <para id="x_450">If you're interested in providing a web interface to your
bos@559 46 own repositories, Mercurial provides two ways to do this. The
bos@559 47 first is using the <command role="hg-cmd">hg serve</command>
bos@559 48 command, which is best suited to short-term
bos@559 49 <quote>lightweight</quote> serving. See section <xref
bos@559 50 linkend="sec:collab:serve"/> below for details of how to use
bos@559 51 this command. If you have a long-lived repository that you'd
bos@559 52 like to make permanently available, Mercurial has built-in
bos@559 53 support for the CGI (Common Gateway Interface) standard, which
bos@559 54 all common web servers support. See section <xref
bos@559 55 linkend="sec:collab:cgi"/> for details of CGI
bos@559 56 configuration.</para>
bos@559 57
bos@559 58 </sect1>
bos@559 59 <sect1>
bos@559 60 <title>Collaboration models</title>
bos@559 61
bos@584 62 <para id="x_451">With a suitably flexible tool, making decisions about
bos@559 63 workflow is much more of a social engineering challenge than a
bos@559 64 technical one. Mercurial imposes few limitations on how you can
bos@559 65 structure the flow of work in a project, so it's up to you and
bos@559 66 your group to set up and live with a model that matches your own
bos@559 67 particular needs.</para>
bos@559 68
bos@559 69 <sect2>
bos@559 70 <title>Factors to keep in mind</title>
bos@559 71
bos@584 72 <para id="x_452">The most important aspect of any model that you must keep
bos@559 73 in mind is how well it matches the needs and capabilities of
bos@559 74 the people who will be using it. This might seem
bos@559 75 self-evident; even so, you still can't afford to forget it for
bos@559 76 a moment.</para>
bos@559 77
bos@584 78 <para id="x_453">I once put together a workflow model that seemed to make
bos@559 79 perfect sense to me, but that caused a considerable amount of
bos@559 80 consternation and strife within my development team. In spite
bos@559 81 of my attempts to explain why we needed a complex set of
bos@559 82 branches, and how changes ought to flow between them, a few
bos@559 83 team members revolted. Even though they were smart people,
bos@559 84 they didn't want to pay attention to the constraints we were
bos@559 85 operating under, or face the consequences of those constraints
bos@559 86 in the details of the model that I was advocating.</para>
bos@559 87
bos@584 88 <para id="x_454">Don't sweep foreseeable social or technical problems under
bos@559 89 the rug. Whatever scheme you put into effect, you should plan
bos@559 90 for mistakes and problem scenarios. Consider adding automated
bos@559 91 machinery to prevent, or quickly recover from, trouble that
bos@559 92 you can anticipate. As an example, if you intend to have a
bos@559 93 branch with not-for-release changes in it, you'd do well to
bos@559 94 think early about the possibility that someone might
bos@559 95 accidentally merge those changes into a release branch. You
bos@559 96 could avoid this particular problem by writing a hook that
bos@559 97 prevents changes from being merged from an inappropriate
bos@559 98 branch.</para>
bos@559 99
bos@559 100 </sect2>
bos@559 101 <sect2>
bos@559 102 <title>Informal anarchy</title>
bos@559 103
bos@584 104 <para id="x_455">I wouldn't suggest an <quote>anything goes</quote>
bos@559 105 approach as something sustainable, but it's a model that's
bos@559 106 easy to grasp, and it works perfectly well in a few unusual
bos@559 107 situations.</para>
bos@559 108
bos@584 109 <para id="x_456">As one example, many projects have a loose-knit group of
bos@559 110 collaborators who rarely physically meet each other. Some
bos@559 111 groups like to overcome the isolation of working at a distance
bos@559 112 by organising occasional <quote>sprints</quote>. In a sprint,
bos@559 113 a number of people get together in a single location (a
bos@559 114 company's conference room, a hotel meeting room, that kind of
bos@559 115 place) and spend several days more or less locked in there,
bos@559 116 hacking intensely on a handful of projects.</para>
bos@559 117
bos@584 118 <para id="x_457">A sprint is the perfect place to use the <command
bos@559 119 role="hg-cmd">hg serve</command> command, since <command
jon@560 120 role="hg-cmd">hg serve</command> does not require any fancy
bos@559 121 server infrastructure. You can get started with <command
bos@559 122 role="hg-cmd">hg serve</command> in moments, by reading
bos@559 123 section <xref linkend="sec:collab:serve"/> below. Then simply
bos@559 124 tell
bos@559 125 the person next to you that you're running a server, send the
bos@559 126 URL to them in an instant message, and you immediately have a
bos@559 127 quick-turnaround way to work together. They can type your URL
bos@559 128 into their web browser and quickly review your changes; or
bos@559 129 they can pull a bugfix from you and verify it; or they can
bos@559 130 clone a branch containing a new feature and try it out.</para>
bos@559 131
bos@584 132 <para id="x_458">The charm, and the problem, with doing things in an ad hoc
bos@559 133 fashion like this is that only people who know about your
bos@559 134 changes, and where they are, can see them. Such an informal
bos@559 135 approach simply doesn't scale beyond a handful people, because
bos@559 136 each individual needs to know about $n$ different repositories
bos@559 137 to pull from.</para>
bos@559 138
bos@559 139 </sect2>
bos@559 140 <sect2>
bos@559 141 <title>A single central repository</title>
bos@559 142
bos@584 143 <para id="x_459">For smaller projects migrating from a centralised revision
bos@559 144 control tool, perhaps the easiest way to get started is to
bos@559 145 have changes flow through a single shared central repository.
bos@559 146 This is also the most common <quote>building block</quote> for
bos@559 147 more ambitious workflow schemes.</para>
bos@559 148
bos@584 149 <para id="x_45a">Contributors start by cloning a copy of this repository.
bos@559 150 They can pull changes from it whenever they need to, and some
bos@559 151 (perhaps all) developers have permission to push a change back
bos@559 152 when they're ready for other people to see it.</para>
bos@559 153
bos@584 154 <para id="x_45b">Under this model, it can still often make sense for people
bos@559 155 to pull changes directly from each other, without going
bos@559 156 through the central repository. Consider a case in which I
bos@559 157 have a tentative bug fix, but I am worried that if I were to
bos@559 158 publish it to the central repository, it might subsequently
bos@559 159 break everyone else's trees as they pull it. To reduce the
bos@559 160 potential for damage, I can ask you to clone my repository
bos@559 161 into a temporary repository of your own and test it. This
bos@559 162 lets us put off publishing the potentially unsafe change until
bos@559 163 it has had a little testing.</para>
bos@559 164
bos@584 165 <para id="x_45c">In this kind of scenario, people usually use the
bos@559 166 <command>ssh</command> protocol to securely push changes to
bos@559 167 the central repository, as documented in section <xref
bos@559 168 linkend="sec:collab:ssh"/>. It's also
bos@559 169 usual to publish a read-only copy of the repository over HTTP
bos@559 170 using CGI, as in section <xref linkend="sec:collab:cgi"/>.
bos@559 171 Publishing over HTTP
bos@559 172 satisfies the needs of people who don't have push access, and
bos@559 173 those who want to use web browsers to browse the repository's
bos@559 174 history.</para>
bos@559 175
bos@559 176 </sect2>
bos@559 177 <sect2>
bos@559 178 <title>Working with multiple branches</title>
bos@559 179
bos@584 180 <para id="x_45d">Projects of any significant size naturally tend to make
bos@559 181 progress on several fronts simultaneously. In the case of
bos@559 182 software, it's common for a project to go through periodic
bos@559 183 official releases. A release might then go into
bos@559 184 <quote>maintenance mode</quote> for a while after its first
bos@559 185 publication; maintenance releases tend to contain only bug
bos@559 186 fixes, not new features. In parallel with these maintenance
bos@559 187 releases, one or more future releases may be under
bos@559 188 development. People normally use the word
bos@559 189 <quote>branch</quote> to refer to one of these many slightly
bos@559 190 different directions in which development is
bos@559 191 proceeding.</para>
bos@559 192
bos@584 193 <para id="x_45e">Mercurial is particularly well suited to managing a number
bos@559 194 of simultaneous, but not identical, branches. Each
bos@559 195 <quote>development direction</quote> can live in its own
bos@559 196 central repository, and you can merge changes from one to
bos@559 197 another as the need arises. Because repositories are
bos@559 198 independent of each other, unstable changes in a development
bos@559 199 branch will never affect a stable branch unless someone
bos@559 200 explicitly merges those changes in.</para>
bos@559 201
bos@584 202 <para id="x_45f">Here's an example of how this can work in practice. Let's
bos@559 203 say you have one <quote>main branch</quote> on a central
bos@567 204 server.</para>
bos@567 205
bos@567 206 &interaction.branching.init;
bos@567 207
bos@584 208 <para id="x_460">People clone it, make changes locally, test them, and push
bos@567 209 them back.</para>
bos@559 210
bos@584 211 <para id="x_461">Once the main branch reaches a release milestone, you can
bos@559 212 use the <command role="hg-cmd">hg tag</command> command to
bos@567 213 give a permanent name to the milestone revision.</para>
bos@567 214
bos@567 215 &interaction.branching.tag;
bos@567 216
bos@584 217 <para id="x_462">Let's say some ongoing
bos@567 218 development occurs on the main branch.</para>
bos@567 219
bos@567 220 &interaction.branching.main;
bos@567 221
bos@584 222 <para id="x_463">Using the tag that was recorded at the milestone, people
bos@567 223 who clone that repository at any time in the future can use
bos@567 224 <command role="hg-cmd">hg update</command> to get a copy of
bos@567 225 the working directory exactly as it was when that tagged
bos@567 226 revision was committed.</para>
bos@567 227
bos@567 228 &interaction.branching.update;
bos@559 229
bos@584 230 <para id="x_464">In addition, immediately after the main branch is tagged,
bos@559 231 someone can then clone the main branch on the server to a new
bos@567 232 <quote>stable</quote> branch, also on the server.</para>
bos@567 233
bos@567 234 &interaction.branching.clone;
bos@559 235
bos@584 236 <para id="x_465">Someone who needs to make a change to the stable branch
bos@559 237 can then clone <emphasis>that</emphasis> repository, make
bos@567 238 their changes, commit, and push their changes back there.</para>
bos@567 239
bos@567 240 &interaction.branching.stable;
bos@567 241
bos@584 242 <para id="x_466">Because Mercurial repositories are independent, and
bos@567 243 Mercurial doesn't move changes around automatically, the
bos@567 244 stable and main branches are <emphasis>isolated</emphasis>
bos@567 245 from each other. The changes that you made on the main branch
bos@567 246 don't <quote>leak</quote> to the stable branch, and vice
bos@567 247 versa.</para>
bos@559 248
bos@584 249 <para id="x_467">You'll often want all of your bugfixes on the stable
bos@559 250 branch to show up on the main branch, too. Rather than
bos@559 251 rewrite a bugfix on the main branch, you can simply pull and
bos@559 252 merge changes from the stable to the main branch, and
bos@567 253 Mercurial will bring those bugfixes in for you.</para>
bos@567 254
bos@567 255 &interaction.branching.merge;
bos@567 256
bos@584 257 <para id="x_468">The main branch will still contain changes that are not on
bos@567 258 the stable branch, but it will also contain all of the
bos@567 259 bugfixes from the stable branch. The stable branch remains
bos@567 260 unaffected by these changes.</para>
bos@559 261
bos@559 262 </sect2>
bos@559 263 <sect2>
bos@559 264 <title>Feature branches</title>
bos@559 265
bos@584 266 <para id="x_469">For larger projects, an effective way to manage change is
bos@559 267 to break up a team into smaller groups. Each group has a
bos@559 268 shared branch of its own, cloned from a single
bos@559 269 <quote>master</quote> branch used by the entire project.
bos@559 270 People working on an individual branch are typically quite
bos@559 271 isolated from developments on other branches.</para>
bos@559 272
bos@591 273 <figure id="fig:collab:feature-branches">
bos@591 274 <title>Feature branches</title>
bos@591 275 <mediaobject>
bos@591 276 <imageobject><imagedata fileref="feature-branches"/></imageobject>
bos@591 277 <textobject><phrase>XXX add text</phrase></textobject>
bos@591 278 </mediaobject>
bos@591 279 </figure>
bos@559 280
bos@584 281 <para id="x_46b">When a particular feature is deemed to be in suitable
bos@559 282 shape, someone on that feature team pulls and merges from the
bos@559 283 master branch into the feature branch, then pushes back up to
bos@559 284 the master branch.</para>
bos@559 285
bos@559 286 </sect2>
bos@559 287 <sect2>
bos@559 288 <title>The release train</title>
bos@559 289
bos@584 290 <para id="x_46c">Some projects are organised on a <quote>train</quote>
bos@559 291 basis: a release is scheduled to happen every few months, and
bos@559 292 whatever features are ready when the <quote>train</quote> is
bos@559 293 ready to leave are allowed in.</para>
bos@559 294
bos@584 295 <para id="x_46d">This model resembles working with feature branches. The
bos@559 296 difference is that when a feature branch misses a train,
bos@559 297 someone on the feature team pulls and merges the changes that
bos@559 298 went out on that train release into the feature branch, and
bos@559 299 the team continues its work on top of that release so that
bos@559 300 their feature can make the next release.</para>
bos@559 301
bos@559 302 </sect2>
bos@559 303 <sect2>
bos@559 304 <title>The Linux kernel model</title>
bos@559 305
bos@584 306 <para id="x_46e">The development of the Linux kernel has a shallow
bos@559 307 hierarchical structure, surrounded by a cloud of apparent
bos@559 308 chaos. Because most Linux developers use
bos@559 309 <command>git</command>, a distributed revision control tool
bos@559 310 with capabilities similar to Mercurial, it's useful to
bos@559 311 describe the way work flows in that environment; if you like
bos@559 312 the ideas, the approach translates well across tools.</para>
bos@559 313
bos@584 314 <para id="x_46f">At the center of the community sits Linus Torvalds, the
bos@559 315 creator of Linux. He publishes a single source repository
bos@559 316 that is considered the <quote>authoritative</quote> current
bos@559 317 tree by the entire developer community. Anyone can clone
bos@559 318 Linus's tree, but he is very choosy about whose trees he pulls
bos@559 319 from.</para>
bos@559 320
bos@584 321 <para id="x_470">Linus has a number of <quote>trusted lieutenants</quote>.
bos@559 322 As a general rule, he pulls whatever changes they publish, in
bos@559 323 most cases without even reviewing those changes. Some of
bos@559 324 those lieutenants are generally agreed to be
bos@559 325 <quote>maintainers</quote>, responsible for specific
bos@559 326 subsystems within the kernel. If a random kernel hacker wants
bos@559 327 to make a change to a subsystem that they want to end up in
bos@559 328 Linus's tree, they must find out who the subsystem's
bos@559 329 maintainer is, and ask that maintainer to take their change.
bos@559 330 If the maintainer reviews their changes and agrees to take
bos@559 331 them, they'll pass them along to Linus in due course.</para>
bos@559 332
bos@584 333 <para id="x_471">Individual lieutenants have their own approaches to
bos@559 334 reviewing, accepting, and publishing changes; and for deciding
bos@559 335 when to feed them to Linus. In addition, there are several
bos@559 336 well known branches that people use for different purposes.
bos@559 337 For example, a few people maintain <quote>stable</quote>
bos@559 338 repositories of older versions of the kernel, to which they
bos@559 339 apply critical fixes as needed. Some maintainers publish
bos@559 340 multiple trees: one for experimental changes; one for changes
bos@559 341 that they are about to feed upstream; and so on. Others just
bos@559 342 publish a single tree.</para>
bos@559 343
bos@584 344 <para id="x_472">This model has two notable features. The first is that
bos@559 345 it's <quote>pull only</quote>. You have to ask, convince, or
bos@559 346 beg another developer to take a change from you, because there
bos@559 347 are almost no trees to which more than one person can push,
bos@559 348 and there's no way to push changes into a tree that someone
bos@559 349 else controls.</para>
bos@559 350
bos@584 351 <para id="x_473">The second is that it's based on reputation and acclaim.
bos@559 352 If you're an unknown, Linus will probably ignore changes from
bos@559 353 you without even responding. But a subsystem maintainer will
bos@559 354 probably review them, and will likely take them if they pass
bos@559 355 their criteria for suitability. The more <quote>good</quote>
bos@559 356 changes you contribute to a maintainer, the more likely they
bos@559 357 are to trust your judgment and accept your changes. If you're
bos@559 358 well-known and maintain a long-lived branch for something
bos@559 359 Linus hasn't yet accepted, people with similar interests may
bos@559 360 pull your changes regularly to keep up with your work.</para>
bos@559 361
bos@584 362 <para id="x_474">Reputation and acclaim don't necessarily cross subsystem
bos@559 363 or <quote>people</quote> boundaries. If you're a respected
bos@559 364 but specialised storage hacker, and you try to fix a
bos@559 365 networking bug, that change will receive a level of scrutiny
bos@559 366 from a network maintainer comparable to a change from a
bos@559 367 complete stranger.</para>
bos@559 368
bos@584 369 <para id="x_475">To people who come from more orderly project backgrounds,
bos@559 370 the comparatively chaotic Linux kernel development process
bos@559 371 often seems completely insane. It's subject to the whims of
bos@559 372 individuals; people make sweeping changes whenever they deem
bos@559 373 it appropriate; and the pace of development is astounding.
bos@559 374 And yet Linux is a highly successful, well-regarded piece of
bos@559 375 software.</para>
bos@559 376
bos@559 377 </sect2>
bos@559 378 <sect2>
bos@559 379 <title>Pull-only versus shared-push collaboration</title>
bos@559 380
bos@584 381 <para id="x_476">A perpetual source of heat in the open source community is
bos@559 382 whether a development model in which people only ever pull
bos@559 383 changes from others is <quote>better than</quote> one in which
bos@559 384 multiple people can push changes to a shared
bos@559 385 repository.</para>
bos@559 386
bos@584 387 <para id="x_477">Typically, the backers of the shared-push model use tools
bos@559 388 that actively enforce this approach. If you're using a
bos@559 389 centralised revision control tool such as Subversion, there's
bos@559 390 no way to make a choice over which model you'll use: the tool
bos@559 391 gives you shared-push, and if you want to do anything else,
bos@559 392 you'll have to roll your own approach on top (such as applying
bos@559 393 a patch by hand).</para>
bos@559 394
bos@584 395 <para id="x_478">A good distributed revision control tool, such as
bos@559 396 Mercurial, will support both models. You and your
bos@559 397 collaborators can then structure how you work together based
bos@559 398 on your own needs and preferences, not on what contortions
bos@559 399 your tools force you into.</para>
bos@559 400
bos@559 401 </sect2>
bos@559 402 <sect2>
bos@559 403 <title>Where collaboration meets branch management</title>
bos@559 404
bos@584 405 <para id="x_479">Once you and your team set up some shared repositories and
bos@559 406 start propagating changes back and forth between local and
bos@559 407 shared repos, you begin to face a related, but slightly
bos@559 408 different challenge: that of managing the multiple directions
bos@559 409 in which your team may be moving at once. Even though this
bos@559 410 subject is intimately related to how your team collaborates,
bos@559 411 it's dense enough to merit treatment of its own, in chapter
bos@559 412 <xref linkend="chap:branch"/>.</para>
bos@559 413
bos@559 414 </sect2>
bos@559 415 </sect1>
bos@559 416 <sect1>
bos@559 417 <title>The technical side of sharing</title>
bos@559 418
bos@584 419 <para id="x_47a">The remainder of this chapter is devoted to the question of
bos@559 420 serving data to your collaborators.</para>
bos@559 421
bos@559 422 </sect1>
bos@559 423 <sect1 id="sec:collab:serve">
bos@559 424 <title>Informal sharing with <command role="hg-cmd">hg
bos@559 425 serve</command></title>
bos@559 426
bos@584 427 <para id="x_47b">Mercurial's <command role="hg-cmd">hg serve</command>
bos@559 428 command is wonderfully suited to small, tight-knit, and
bos@559 429 fast-paced group environments. It also provides a great way to
bos@559 430 get a feel for using Mercurial commands over a network.</para>
bos@559 431
bos@584 432 <para id="x_47c">Run <command role="hg-cmd">hg serve</command> inside a
bos@559 433 repository, and in under a second it will bring up a specialised
bos@559 434 HTTP server; this will accept connections from any client, and
bos@559 435 serve up data for that repository until you terminate it.
bos@559 436 Anyone who knows the URL of the server you just started, and can
bos@559 437 talk to your computer over the network, can then use a web
bos@559 438 browser or Mercurial to read data from that repository. A URL
bos@559 439 for a <command role="hg-cmd">hg serve</command> instance running
bos@559 440 on a laptop is likely to look something like
bos@559 441 <literal>http://my-laptop.local:8000/</literal>.</para>
bos@559 442
bos@584 443 <para id="x_47d">The <command role="hg-cmd">hg serve</command> command is
bos@559 444 <emphasis>not</emphasis> a general-purpose web server. It can do
bos@559 445 only two things:</para>
bos@559 446 <itemizedlist>
bos@584 447 <listitem><para id="x_47e">Allow people to browse the history of the
bos@559 448 repository it's serving, from their normal web
bos@559 449 browsers.</para>
bos@559 450 </listitem>
bos@584 451 <listitem><para id="x_47f">Speak Mercurial's wire protocol, so that people
bos@559 452 can <command role="hg-cmd">hg clone</command> or <command
bos@559 453 role="hg-cmd">hg pull</command> changes from that
bos@559 454 repository.</para>
bos@559 455 </listitem></itemizedlist>
bos@584 456 <para id="x_480">In particular, <command role="hg-cmd">hg serve</command>
bos@559 457 won't allow remote users to <emphasis>modify</emphasis> your
bos@559 458 repository. It's intended for read-only use.</para>
bos@559 459
bos@584 460 <para id="x_481">If you're getting started with Mercurial, there's nothing to
bos@559 461 prevent you from using <command role="hg-cmd">hg serve</command>
bos@559 462 to serve up a repository on your own computer, then use commands
bos@559 463 like <command role="hg-cmd">hg clone</command>, <command
bos@559 464 role="hg-cmd">hg incoming</command>, and so on to talk to that
bos@559 465 server as if the repository was hosted remotely. This can help
bos@559 466 you to quickly get acquainted with using commands on
bos@559 467 network-hosted repositories.</para>
bos@559 468
bos@559 469 <sect2>
bos@559 470 <title>A few things to keep in mind</title>
bos@559 471
bos@584 472 <para id="x_482">Because it provides unauthenticated read access to all
bos@559 473 clients, you should only use <command role="hg-cmd">hg
bos@559 474 serve</command> in an environment where you either don't
bos@559 475 care, or have complete control over, who can access your
bos@559 476 network and pull data from your repository.</para>
bos@559 477
bos@584 478 <para id="x_483">The <command role="hg-cmd">hg serve</command> command
bos@559 479 knows nothing about any firewall software you might have
bos@559 480 installed on your system or network. It cannot detect or
bos@559 481 control your firewall software. If other people are unable to
bos@559 482 talk to a running <command role="hg-cmd">hg serve</command>
bos@559 483 instance, the second thing you should do
bos@559 484 (<emphasis>after</emphasis> you make sure that they're using
bos@559 485 the correct URL) is check your firewall configuration.</para>
bos@559 486
bos@584 487 <para id="x_484">By default, <command role="hg-cmd">hg serve</command>
bos@559 488 listens for incoming connections on port 8000. If another
bos@559 489 process is already listening on the port you want to use, you
bos@559 490 can specify a different port to listen on using the <option
bos@559 491 role="hg-opt-serve">-p</option> option.</para>
bos@559 492
bos@584 493 <para id="x_485">Normally, when <command role="hg-cmd">hg serve</command>
bos@559 494 starts, it prints no output, which can be a bit unnerving. If
bos@559 495 you'd like to confirm that it is indeed running correctly, and
bos@559 496 find out what URL you should send to your collaborators, start
bos@559 497 it with the <option role="hg-opt-global">-v</option>
bos@559 498 option.</para>
bos@559 499
bos@559 500 </sect2>
bos@559 501 </sect1>
bos@559 502 <sect1 id="sec:collab:ssh">
bos@559 503 <title>Using the Secure Shell (ssh) protocol</title>
bos@559 504
bos@584 505 <para id="x_486">You can pull and push changes securely over a network
bos@559 506 connection using the Secure Shell (<literal>ssh</literal>)
bos@559 507 protocol. To use this successfully, you may have to do a little
bos@559 508 bit of configuration on the client or server sides.</para>
bos@559 509
bos@584 510 <para id="x_487">If you're not familiar with ssh, it's a network protocol
bos@559 511 that lets you securely communicate with another computer. To
bos@559 512 use it with Mercurial, you'll be setting up one or more user
bos@559 513 accounts on a server so that remote users can log in and execute
bos@559 514 commands.</para>
bos@559 515
bos@584 516 <para id="x_488">(If you <emphasis>are</emphasis> familiar with ssh, you'll
bos@559 517 probably find some of the material that follows to be elementary
bos@559 518 in nature.)</para>
bos@559 519
bos@559 520 <sect2>
bos@559 521 <title>How to read and write ssh URLs</title>
bos@559 522
bos@584 523 <para id="x_489">An ssh URL tends to look like this:</para>
bos@559 524 <programlisting>ssh://bos@hg.serpentine.com:22/hg/hgbook</programlisting>
bos@559 525 <orderedlist>
bos@584 526 <listitem><para id="x_48a">The <quote><literal>ssh://</literal></quote>
bos@559 527 part tells Mercurial to use the ssh protocol.</para>
bos@559 528 </listitem>
bos@584 529 <listitem><para id="x_48b">The <quote><literal>bos@</literal></quote>
bos@559 530 component indicates what username to log into the server
bos@559 531 as. You can leave this out if the remote username is the
bos@559 532 same as your local username.</para>
bos@559 533 </listitem>
bos@584 534 <listitem><para id="x_48c">The
bos@559 535 <quote><literal>hg.serpentine.com</literal></quote> gives
bos@559 536 the hostname of the server to log into.</para>
bos@559 537 </listitem>
bos@584 538 <listitem><para id="x_48d">The <quote>:22</quote> identifies the port
bos@559 539 number to connect to the server on. The default port is
bos@579 540 22, so you only need to specify a colon and port number if
bos@579 541 you're <emphasis>not</emphasis> using port 22.</para>
bos@559 542 </listitem>
bos@584 543 <listitem><para id="x_48e">The remainder of the URL is the local path to
bos@559 544 the repository on the server.</para>
bos@559 545 </listitem></orderedlist>
bos@559 546
bos@584 547 <para id="x_48f">There's plenty of scope for confusion with the path
bos@559 548 component of ssh URLs, as there is no standard way for tools
bos@559 549 to interpret it. Some programs behave differently than others
bos@559 550 when dealing with these paths. This isn't an ideal situation,
bos@559 551 but it's unlikely to change. Please read the following
bos@559 552 paragraphs carefully.</para>
bos@559 553
bos@584 554 <para id="x_490">Mercurial treats the path to a repository on the server as
bos@559 555 relative to the remote user's home directory. For example, if
bos@559 556 user <literal>foo</literal> on the server has a home directory
bos@559 557 of <filename class="directory">/home/foo</filename>, then an
bos@559 558 ssh URL that contains a path component of <filename
bos@559 559 class="directory">bar</filename> <emphasis>really</emphasis>
bos@559 560 refers to the directory <filename
bos@559 561 class="directory">/home/foo/bar</filename>.</para>
bos@559 562
bos@584 563 <para id="x_491">If you want to specify a path relative to another user's
bos@559 564 home directory, you can use a path that starts with a tilde
bos@559 565 character followed by the user's name (let's call them
bos@559 566 <literal>otheruser</literal>), like this.</para>
bos@559 567 <programlisting>ssh://server/~otheruser/hg/repo</programlisting>
bos@559 568
bos@584 569 <para id="x_492">And if you really want to specify an
bos@559 570 <emphasis>absolute</emphasis> path on the server, begin the
bos@559 571 path component with two slashes, as in this example.</para>
bos@559 572 <programlisting>ssh://server//absolute/path</programlisting>
bos@559 573
bos@559 574 </sect2>
bos@559 575 <sect2>
bos@559 576 <title>Finding an ssh client for your system</title>
bos@559 577
bos@584 578 <para id="x_493">Almost every Unix-like system comes with OpenSSH
bos@559 579 preinstalled. If you're using such a system, run
bos@559 580 <literal>which ssh</literal> to find out if the
bos@559 581 <command>ssh</command> command is installed (it's usually in
bos@559 582 <filename class="directory">/usr/bin</filename>). In the
bos@559 583 unlikely event that it isn't present, take a look at your
bos@559 584 system documentation to figure out how to install it.</para>
bos@559 585
bos@584 586 <para id="x_494">On Windows, you'll first need to download a suitable ssh
bos@559 587 client. There are two alternatives.</para>
bos@559 588 <itemizedlist>
bos@584 589 <listitem><para id="x_495">Simon Tatham's excellent PuTTY package
bos@559 590 <citation>web:putty</citation> provides a complete suite
bos@559 591 of ssh client commands.</para>
bos@559 592 </listitem>
bos@584 593 <listitem><para id="x_496">If you have a high tolerance for pain, you can
bos@559 594 use the Cygwin port of OpenSSH.</para>
bos@559 595 </listitem></itemizedlist>
bos@584 596 <para id="x_497">In either case, you'll need to edit your <filename
bos@580 597 role="special">hg.ini</filename> file to
bos@559 598 tell Mercurial where to find the actual client command. For
bos@559 599 example, if you're using PuTTY, you'll need to use the
bos@559 600 <command>plink</command> command as a command-line ssh
bos@559 601 client.</para>
bos@579 602 <programlisting>[ui]
bos@579 603 ssh = C:/path/to/plink.exe -ssh -i "C:/path/to/my/private/key"</programlisting>
bos@559 604
bos@559 605 <note>
bos@584 606 <para id="x_498"> The path to <command>plink</command> shouldn't contain
bos@559 607 any whitespace characters, or Mercurial may not be able to
bos@559 608 run it correctly (so putting it in <filename
bos@580 609 class="directory">C:\Program Files</filename> is probably
bos@559 610 not a good idea).</para>
bos@559 611 </note>
bos@559 612
bos@559 613 </sect2>
bos@559 614 <sect2>
bos@559 615 <title>Generating a key pair</title>
bos@559 616
bos@584 617 <para id="x_499">To avoid the need to repetitively type a password every
bos@559 618 time you need to use your ssh client, I recommend generating a
bos@559 619 key pair. On a Unix-like system, the
bos@559 620 <command>ssh-keygen</command> command will do the trick. On
bos@559 621 Windows, if you're using PuTTY, the
bos@559 622 <command>puttygen</command> command is what you'll
bos@559 623 need.</para>
bos@559 624
bos@584 625 <para id="x_49a">When you generate a key pair, it's usually
bos@559 626 <emphasis>highly</emphasis> advisable to protect it with a
bos@559 627 passphrase. (The only time that you might not want to do this
bos@559 628 is when you're using the ssh protocol for automated tasks on a
bos@559 629 secure network.)</para>
bos@559 630
bos@584 631 <para id="x_49b">Simply generating a key pair isn't enough, however.
bos@559 632 You'll need to add the public key to the set of authorised
bos@559 633 keys for whatever user you're logging in remotely as. For
bos@559 634 servers using OpenSSH (the vast majority), this will mean
bos@559 635 adding the public key to a list in a file called <filename
bos@559 636 role="special">authorized_keys</filename> in their <filename
bos@559 637 role="special" class="directory">.ssh</filename>
bos@559 638 directory.</para>
bos@559 639
bos@584 640 <para id="x_49c">On a Unix-like system, your public key will have a
bos@559 641 <filename>.pub</filename> extension. If you're using
bos@559 642 <command>puttygen</command> on Windows, you can save the
bos@559 643 public key to a file of your choosing, or paste it from the
bos@559 644 window it's displayed in straight into the <filename
bos@559 645 role="special">authorized_keys</filename> file.</para>
bos@559 646
bos@559 647 </sect2>
bos@559 648 <sect2>
bos@559 649 <title>Using an authentication agent</title>
bos@559 650
bos@584 651 <para id="x_49d">An authentication agent is a daemon that stores
bos@559 652 passphrases in memory (so it will forget passphrases if you
bos@559 653 log out and log back in again). An ssh client will notice if
bos@559 654 it's running, and query it for a passphrase. If there's no
bos@559 655 authentication agent running, or the agent doesn't store the
bos@559 656 necessary passphrase, you'll have to type your passphrase
bos@559 657 every time Mercurial tries to communicate with a server on
bos@559 658 your behalf (e.g. whenever you pull or push changes).</para>
bos@559 659
bos@584 660 <para id="x_49e">The downside of storing passphrases in an agent is that
bos@559 661 it's possible for a well-prepared attacker to recover the
bos@559 662 plain text of your passphrases, in some cases even if your
bos@559 663 system has been power-cycled. You should make your own
bos@559 664 judgment as to whether this is an acceptable risk. It
bos@559 665 certainly saves a lot of repeated typing.</para>
bos@559 666
bos@584 667 <para id="x_49f">On Unix-like systems, the agent is called
bos@559 668 <command>ssh-agent</command>, and it's often run automatically
bos@559 669 for you when you log in. You'll need to use the
bos@559 670 <command>ssh-add</command> command to add passphrases to the
bos@559 671 agent's store. On Windows, if you're using PuTTY, the
bos@559 672 <command>pageant</command> command acts as the agent. It adds
bos@559 673 an icon to your system tray that will let you manage stored
bos@559 674 passphrases.</para>
bos@559 675
bos@559 676 </sect2>
bos@559 677 <sect2>
bos@559 678 <title>Configuring the server side properly</title>
bos@559 679
bos@584 680 <para id="x_4a0">Because ssh can be fiddly to set up if you're new to it,
bos@559 681 there's a variety of things that can go wrong. Add Mercurial
bos@559 682 on top, and there's plenty more scope for head-scratching.
bos@559 683 Most of these potential problems occur on the server side, not
bos@559 684 the client side. The good news is that once you've gotten a
bos@559 685 configuration working, it will usually continue to work
bos@559 686 indefinitely.</para>
bos@559 687
bos@584 688 <para id="x_4a1">Before you try using Mercurial to talk to an ssh server,
bos@559 689 it's best to make sure that you can use the normal
bos@559 690 <command>ssh</command> or <command>putty</command> command to
bos@559 691 talk to the server first. If you run into problems with using
bos@559 692 these commands directly, Mercurial surely won't work. Worse,
bos@559 693 it will obscure the underlying problem. Any time you want to
bos@559 694 debug ssh-related Mercurial problems, you should drop back to
bos@559 695 making sure that plain ssh client commands work first,
bos@559 696 <emphasis>before</emphasis> you worry about whether there's a
bos@559 697 problem with Mercurial.</para>
bos@559 698
bos@584 699 <para id="x_4a2">The first thing to be sure of on the server side is that
bos@559 700 you can actually log in from another machine at all. If you
bos@559 701 can't use <command>ssh</command> or <command>putty</command>
bos@559 702 to log in, the error message you get may give you a few hints
bos@559 703 as to what's wrong. The most common problems are as
bos@559 704 follows.</para>
bos@559 705 <itemizedlist>
bos@584 706 <listitem><para id="x_4a3">If you get a <quote>connection refused</quote>
bos@559 707 error, either there isn't an SSH daemon running on the
bos@559 708 server at all, or it's inaccessible due to firewall
bos@559 709 configuration.</para>
bos@559 710 </listitem>
bos@584 711 <listitem><para id="x_4a4">If you get a <quote>no route to host</quote>
bos@559 712 error, you either have an incorrect address for the server
bos@559 713 or a seriously locked down firewall that won't admit its
bos@559 714 existence at all.</para>
bos@559 715 </listitem>
bos@584 716 <listitem><para id="x_4a5">If you get a <quote>permission denied</quote>
bos@559 717 error, you may have mistyped the username on the server,
bos@559 718 or you could have mistyped your key's passphrase or the
bos@559 719 remote user's password.</para>
bos@559 720 </listitem></itemizedlist>
bos@584 721 <para id="x_4a6">In summary, if you're having trouble talking to the
bos@559 722 server's ssh daemon, first make sure that one is running at
bos@559 723 all. On many systems it will be installed, but disabled, by
bos@559 724 default. Once you're done with this step, you should then
bos@559 725 check that the server's firewall is configured to allow
bos@559 726 incoming connections on the port the ssh daemon is listening
bos@559 727 on (usually 22). Don't worry about more exotic possibilities
bos@559 728 for misconfiguration until you've checked these two
bos@559 729 first.</para>
bos@559 730
bos@584 731 <para id="x_4a7">If you're using an authentication agent on the client side
bos@559 732 to store passphrases for your keys, you ought to be able to
bos@559 733 log into the server without being prompted for a passphrase or
bos@559 734 a password. If you're prompted for a passphrase, there are a
bos@559 735 few possible culprits.</para>
bos@559 736 <itemizedlist>
bos@584 737 <listitem><para id="x_4a8">You might have forgotten to use
bos@559 738 <command>ssh-add</command> or <command>pageant</command>
bos@559 739 to store the passphrase.</para>
bos@559 740 </listitem>
bos@584 741 <listitem><para id="x_4a9">You might have stored the passphrase for the
bos@559 742 wrong key.</para>
bos@559 743 </listitem></itemizedlist>
bos@584 744 <para id="x_4aa">If you're being prompted for the remote user's password,
bos@559 745 there are another few possible problems to check.</para>
bos@559 746 <itemizedlist>
bos@584 747 <listitem><para id="x_4ab">Either the user's home directory or their
bos@559 748 <filename role="special" class="directory">.ssh</filename>
bos@559 749 directory might have excessively liberal permissions. As
bos@559 750 a result, the ssh daemon will not trust or read their
bos@559 751 <filename role="special">authorized_keys</filename> file.
bos@559 752 For example, a group-writable home or <filename
bos@559 753 role="special" class="directory">.ssh</filename>
bos@559 754 directory will often cause this symptom.</para>
bos@559 755 </listitem>
bos@584 756 <listitem><para id="x_4ac">The user's <filename
bos@559 757 role="special">authorized_keys</filename> file may have
bos@559 758 a problem. If anyone other than the user owns or can write
bos@559 759 to that file, the ssh daemon will not trust or read
bos@559 760 it.</para>
bos@559 761 </listitem></itemizedlist>
bos@559 762
bos@584 763 <para id="x_4ad">In the ideal world, you should be able to run the
bos@559 764 following command successfully, and it should print exactly
bos@559 765 one line of output, the current date and time.</para>
bos@559 766 <programlisting>ssh myserver date</programlisting>
bos@559 767
bos@584 768 <para id="x_4ae">If, on your server, you have login scripts that print
bos@559 769 banners or other junk even when running non-interactive
bos@559 770 commands like this, you should fix them before you continue,
bos@559 771 so that they only print output if they're run interactively.
bos@559 772 Otherwise these banners will at least clutter up Mercurial's
bos@559 773 output. Worse, they could potentially cause problems with
bos@559 774 running Mercurial commands remotely. Mercurial makes tries to
bos@559 775 detect and ignore banners in non-interactive
bos@559 776 <command>ssh</command> sessions, but it is not foolproof. (If
bos@559 777 you're editing your login scripts on your server, the usual
bos@559 778 way to see if a login script is running in an interactive
bos@559 779 shell is to check the return code from the command
bos@559 780 <literal>tty -s</literal>.)</para>
bos@559 781
bos@584 782 <para id="x_4af">Once you've verified that plain old ssh is working with
bos@559 783 your server, the next step is to ensure that Mercurial runs on
bos@559 784 the server. The following command should run
bos@559 785 successfully:</para>
bos@580 786
bos@559 787 <programlisting>ssh myserver hg version</programlisting>
bos@580 788
bos@584 789 <para id="x_4b0">If you see an error message instead of normal <command
bos@559 790 role="hg-cmd">hg version</command> output, this is usually
bos@559 791 because you haven't installed Mercurial to <filename
bos@559 792 class="directory">/usr/bin</filename>. Don't worry if this
bos@559 793 is the case; you don't need to do that. But you should check
bos@559 794 for a few possible problems.</para>
bos@559 795 <itemizedlist>
bos@584 796 <listitem><para id="x_4b1">Is Mercurial really installed on the server at
bos@559 797 all? I know this sounds trivial, but it's worth
bos@559 798 checking!</para>
bos@559 799 </listitem>
bos@584 800 <listitem><para id="x_4b2">Maybe your shell's search path (usually set
bos@559 801 via the <envar>PATH</envar> environment variable) is
bos@559 802 simply misconfigured.</para>
bos@559 803 </listitem>
bos@584 804 <listitem><para id="x_4b3">Perhaps your <envar>PATH</envar> environment
bos@559 805 variable is only being set to point to the location of the
bos@559 806 <command>hg</command> executable if the login session is
bos@559 807 interactive. This can happen if you're setting the path
bos@559 808 in the wrong shell login script. See your shell's
bos@559 809 documentation for details.</para>
bos@559 810 </listitem>
bos@584 811 <listitem><para id="x_4b4">The <envar>PYTHONPATH</envar> environment
bos@559 812 variable may need to contain the path to the Mercurial
bos@559 813 Python modules. It might not be set at all; it could be
bos@559 814 incorrect; or it may be set only if the login is
bos@559 815 interactive.</para>
bos@559 816 </listitem></itemizedlist>
bos@559 817
bos@584 818 <para id="x_4b5">If you can run <command role="hg-cmd">hg version</command>
bos@559 819 over an ssh connection, well done! You've got the server and
bos@559 820 client sorted out. You should now be able to use Mercurial to
bos@559 821 access repositories hosted by that username on that server.
bos@559 822 If you run into problems with Mercurial and ssh at this point,
bos@559 823 try using the <option role="hg-opt-global">--debug</option>
bos@559 824 option to get a clearer picture of what's going on.</para>
bos@559 825
bos@559 826 </sect2>
bos@559 827 <sect2>
bos@559 828 <title>Using compression with ssh</title>
bos@559 829
bos@584 830 <para id="x_4b6">Mercurial does not compress data when it uses the ssh
bos@559 831 protocol, because the ssh protocol can transparently compress
bos@559 832 data. However, the default behaviour of ssh clients is
bos@559 833 <emphasis>not</emphasis> to request compression.</para>
bos@559 834
bos@584 835 <para id="x_4b7">Over any network other than a fast LAN (even a wireless
bos@559 836 network), using compression is likely to significantly speed
bos@559 837 up Mercurial's network operations. For example, over a WAN,
bos@559 838 someone measured compression as reducing the amount of time
bos@559 839 required to clone a particularly large repository from 51
bos@559 840 minutes to 17 minutes.</para>
bos@559 841
bos@584 842 <para id="x_4b8">Both <command>ssh</command> and <command>plink</command>
bos@559 843 accept a <option role="cmd-opt-ssh">-C</option> option which
bos@559 844 turns on compression. You can easily edit your <filename
bos@580 845 role="special">~/.hgrc</filename> to enable compression for
bos@559 846 all of Mercurial's uses of the ssh protocol.</para>
bos@579 847 <programlisting>[ui]
bos@579 848 ssh = ssh -C</programlisting>
bos@559 849
bos@584 850 <para id="x_4b9">If you use <command>ssh</command>, you can configure it to
bos@559 851 always use compression when talking to your server. To do
bos@559 852 this, edit your <filename
bos@559 853 role="special">.ssh/config</filename> file (which may not
bos@559 854 yet exist), as follows.</para>
bos@579 855 <programlisting>Host hg
bos@579 856 Compression yes
bos@579 857 HostName hg.example.com</programlisting>
bos@584 858 <para id="x_4ba">This defines an alias, <literal>hg</literal>. When you
bos@559 859 use it on the <command>ssh</command> command line or in a
bos@559 860 Mercurial <literal>ssh</literal>-protocol URL, it will cause
bos@559 861 <command>ssh</command> to connect to
bos@559 862 <literal>hg.example.com</literal> and use compression. This
bos@559 863 gives you both a shorter name to type and compression, each of
bos@559 864 which is a good thing in its own right.</para>
bos@559 865
bos@559 866 </sect2>
bos@559 867 </sect1>
bos@559 868 <sect1 id="sec:collab:cgi">
bos@559 869 <title>Serving over HTTP using CGI</title>
bos@559 870
bos@584 871 <para id="x_4bb">Depending on how ambitious you are, configuring Mercurial's
bos@559 872 CGI interface can take anything from a few moments to several
bos@559 873 hours.</para>
bos@559 874
bos@584 875 <para id="x_4bc">We'll begin with the simplest of examples, and work our way
bos@559 876 towards a more complex configuration. Even for the most basic
bos@559 877 case, you're almost certainly going to need to read and modify
bos@559 878 your web server's configuration.</para>
bos@559 879
bos@559 880 <note>
bos@584 881 <para id="x_4bd"> Configuring a web server is a complex, fiddly, and
bos@559 882 highly system-dependent activity. I can't possibly give you
bos@559 883 instructions that will cover anything like all of the cases
bos@559 884 you will encounter. Please use your discretion and judgment in
bos@559 885 following the sections below. Be prepared to make plenty of
bos@559 886 mistakes, and to spend a lot of time reading your server's
bos@559 887 error logs.</para>
bos@559 888 </note>
bos@559 889
bos@559 890 <sect2>
bos@559 891 <title>Web server configuration checklist</title>
bos@559 892
bos@584 893 <para id="x_4be">Before you continue, do take a few moments to check a few
bos@559 894 aspects of your system's setup.</para>
bos@559 895
bos@559 896 <orderedlist>
bos@584 897 <listitem><para id="x_4bf">Do you have a web server installed at all?
bos@559 898 Mac OS X ships with Apache, but many other systems may not
bos@559 899 have a web server installed.</para>
bos@559 900 </listitem>
bos@584 901 <listitem><para id="x_4c0">If you have a web server installed, is it
bos@559 902 actually running? On most systems, even if one is
bos@559 903 present, it will be disabled by default.</para>
bos@559 904 </listitem>
bos@584 905 <listitem><para id="x_4c1">Is your server configured to allow you to run
bos@559 906 CGI programs in the directory where you plan to do so?
bos@559 907 Most servers default to explicitly disabling the ability
bos@559 908 to run CGI programs.</para>
bos@559 909 </listitem></orderedlist>
bos@559 910
bos@584 911 <para id="x_4c2">If you don't have a web server installed, and don't have
bos@559 912 substantial experience configuring Apache, you should consider
bos@559 913 using the <literal>lighttpd</literal> web server instead of
bos@559 914 Apache. Apache has a well-deserved reputation for baroque and
bos@559 915 confusing configuration. While <literal>lighttpd</literal> is
bos@559 916 less capable in some ways than Apache, most of these
bos@559 917 capabilities are not relevant to serving Mercurial
bos@559 918 repositories. And <literal>lighttpd</literal> is undeniably
bos@559 919 <emphasis>much</emphasis> easier to get started with than
bos@559 920 Apache.</para>
bos@559 921
bos@559 922 </sect2>
bos@559 923 <sect2>
bos@559 924 <title>Basic CGI configuration</title>
bos@559 925
bos@584 926 <para id="x_4c3">On Unix-like systems, it's common for users to have a
bos@559 927 subdirectory named something like <filename
bos@559 928 class="directory">public_html</filename> in their home
bos@559 929 directory, from which they can serve up web pages. A file
bos@559 930 named <filename>foo</filename> in this directory will be
bos@559 931 accessible at a URL of the form
bos@580 932 <literal>http://www.example.com/username/foo</literal>.</para>
bos@559 933
bos@584 934 <para id="x_4c4">To get started, find the <filename
bos@559 935 role="special">hgweb.cgi</filename> script that should be
bos@559 936 present in your Mercurial installation. If you can't quickly
bos@559 937 find a local copy on your system, simply download one from the
bos@559 938 master Mercurial repository at <ulink
bos@559 939 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@559 940
bos@584 941 <para id="x_4c5">You'll need to copy this script into your <filename
bos@559 942 class="directory">public_html</filename> directory, and
bos@559 943 ensure that it's executable.</para>
bos@579 944 <programlisting>cp .../hgweb.cgi ~/public_html
bos@579 945 chmod 755 ~/public_html/hgweb.cgi</programlisting>
bos@584 946 <para id="x_4c6">The <literal>755</literal> argument to
bos@559 947 <command>chmod</command> is a little more general than just
bos@559 948 making the script executable: it ensures that the script is
bos@559 949 executable by anyone, and that <quote>group</quote> and
bos@559 950 <quote>other</quote> write permissions are
bos@559 951 <emphasis>not</emphasis> set. If you were to leave those
bos@559 952 write permissions enabled, Apache's <literal>suexec</literal>
bos@559 953 subsystem would likely refuse to execute the script. In fact,
bos@559 954 <literal>suexec</literal> also insists that the
bos@559 955 <emphasis>directory</emphasis> in which the script resides
bos@559 956 must not be writable by others.</para>
bos@559 957 <programlisting>chmod 755 ~/public_html</programlisting>
bos@559 958
bos@559 959 <sect3 id="sec:collab:wtf">
bos@559 960 <title>What could <emphasis>possibly</emphasis> go
bos@559 961 wrong?</title>
bos@559 962
bos@584 963 <para id="x_4c7">Once you've copied the CGI script into place, go into a
bos@559 964 web browser, and try to open the URL <ulink
bos@559 965 url="http://myhostname/
bos@559 966 myuser/hgweb.cgi">http://myhostname/
bos@559 967 myuser/hgweb.cgi</ulink>, <emphasis>but</emphasis> brace
bos@559 968 yourself for instant failure. There's a high probability
bos@559 969 that trying to visit this URL will fail, and there are many
bos@559 970 possible reasons for this. In fact, you're likely to
bos@559 971 stumble over almost every one of the possible errors below,
bos@559 972 so please read carefully. The following are all of the
bos@559 973 problems I ran into on a system running Fedora 7, with a
bos@559 974 fresh installation of Apache, and a user account that I
bos@559 975 created specially to perform this exercise.</para>
bos@559 976
bos@584 977 <para id="x_4c8">Your web server may have per-user directories disabled.
bos@559 978 If you're using Apache, search your config file for a
bos@559 979 <literal>UserDir</literal> directive. If there's none
bos@559 980 present, per-user directories will be disabled. If one
bos@559 981 exists, but its value is <literal>disabled</literal>, then
bos@559 982 per-user directories will be disabled. Otherwise, the
bos@559 983 string after <literal>UserDir</literal> gives the name of
bos@559 984 the subdirectory that Apache will look in under your home
bos@559 985 directory, for example <filename
bos@559 986 class="directory">public_html</filename>.</para>
bos@559 987
bos@584 988 <para id="x_4c9">Your file access permissions may be too restrictive.
bos@559 989 The web server must be able to traverse your home directory
bos@559 990 and directories under your <filename
bos@559 991 class="directory">public_html</filename> directory, and
bos@559 992 read files under the latter too. Here's a quick recipe to
bos@559 993 help you to make your permissions more appropriate.</para>
bos@579 994 <programlisting>chmod 755 ~
bos@579 995 find ~/public_html -type d -print0 | xargs -0r chmod 755
bos@579 996 find ~/public_html -type f -print0 | xargs -0r chmod 644</programlisting>
bos@559 997
bos@584 998 <para id="x_4ca">The other possibility with permissions is that you might
bos@559 999 get a completely empty window when you try to load the
bos@559 1000 script. In this case, it's likely that your access
ori@561 1001 permissions are <emphasis>too permissive</emphasis>. Apache's
bos@559 1002 <literal>suexec</literal> subsystem won't execute a script
bos@559 1003 that's group- or world-writable, for example.</para>
bos@559 1004
bos@584 1005 <para id="x_4cb">Your web server may be configured to disallow execution
bos@559 1006 of CGI programs in your per-user web directory. Here's
bos@559 1007 Apache's default per-user configuration from my Fedora
bos@559 1008 system.</para>
bos@579 1009
bos@579 1010 &ch06-apache-config.lst;
bos@579 1011
bos@584 1012 <para id="x_4cc">If you find a similar-looking
bos@559 1013 <literal>Directory</literal> group in your Apache
bos@559 1014 configuration, the directive to look at inside it is
bos@559 1015 <literal>Options</literal>. Add <literal>ExecCGI</literal>
bos@559 1016 to the end of this list if it's missing, and restart the web
bos@559 1017 server.</para>
bos@559 1018
bos@584 1019 <para id="x_4cd">If you find that Apache serves you the text of the CGI
bos@559 1020 script instead of executing it, you may need to either
bos@559 1021 uncomment (if already present) or add a directive like
bos@559 1022 this.</para>
bos@559 1023 <programlisting>AddHandler cgi-script .cgi</programlisting>
bos@559 1024
bos@584 1025 <para id="x_4ce">The next possibility is that you might be served with a
bos@559 1026 colourful Python backtrace claiming that it can't import a
bos@559 1027 <literal>mercurial</literal>-related module. This is
bos@559 1028 actually progress! The server is now capable of executing
bos@559 1029 your CGI script. This error is only likely to occur if
bos@559 1030 you're running a private installation of Mercurial, instead
bos@559 1031 of a system-wide version. Remember that the web server runs
bos@559 1032 the CGI program without any of the environment variables
bos@559 1033 that you take for granted in an interactive session. If
bos@559 1034 this error happens to you, edit your copy of <filename
bos@559 1035 role="special">hgweb.cgi</filename> and follow the
bos@559 1036 directions inside it to correctly set your
bos@559 1037 <envar>PYTHONPATH</envar> environment variable.</para>
bos@559 1038
bos@584 1039 <para id="x_4cf">Finally, you are <emphasis>certain</emphasis> to by
bos@559 1040 served with another colourful Python backtrace: this one
bos@559 1041 will complain that it can't find <filename
bos@559 1042 class="directory">/path/to/repository</filename>. Edit
bos@559 1043 your <filename role="special">hgweb.cgi</filename> script
bos@559 1044 and replace the <filename
bos@559 1045 class="directory">/path/to/repository</filename> string
bos@559 1046 with the complete path to the repository you want to serve
bos@559 1047 up.</para>
bos@559 1048
bos@584 1049 <para id="x_4d0">At this point, when you try to reload the page, you
bos@559 1050 should be presented with a nice HTML view of your
bos@559 1051 repository's history. Whew!</para>
bos@559 1052
bos@559 1053 </sect3>
bos@559 1054 <sect3>
bos@559 1055 <title>Configuring lighttpd</title>
bos@559 1056
bos@584 1057 <para id="x_4d1">To be exhaustive in my experiments, I tried configuring
bos@559 1058 the increasingly popular <literal>lighttpd</literal> web
bos@559 1059 server to serve the same repository as I described with
bos@559 1060 Apache above. I had already overcome all of the problems I
bos@559 1061 outlined with Apache, many of which are not server-specific.
bos@559 1062 As a result, I was fairly sure that my file and directory
bos@559 1063 permissions were good, and that my <filename
bos@559 1064 role="special">hgweb.cgi</filename> script was properly
bos@559 1065 edited.</para>
bos@559 1066
bos@584 1067 <para id="x_4d2">Once I had Apache running, getting
bos@559 1068 <literal>lighttpd</literal> to serve the repository was a
bos@559 1069 snap (in other words, even if you're trying to use
bos@559 1070 <literal>lighttpd</literal>, you should read the Apache
bos@559 1071 section). I first had to edit the
bos@559 1072 <literal>mod_access</literal> section of its config file to
bos@559 1073 enable <literal>mod_cgi</literal> and
bos@559 1074 <literal>mod_userdir</literal>, both of which were disabled
bos@559 1075 by default on my system. I then added a few lines to the
bos@559 1076 end of the config file, to configure these modules.</para>
bos@580 1077 <programlisting>userdir.path = "public_html"
bos@580 1078 cgi.assign = (".cgi" =&gt; "" )</programlisting>
bos@584 1079 <para id="x_4d3">With this done, <literal>lighttpd</literal> ran
bos@559 1080 immediately for me. If I had configured
bos@559 1081 <literal>lighttpd</literal> before Apache, I'd almost
bos@559 1082 certainly have run into many of the same system-level
bos@559 1083 configuration problems as I did with Apache. However, I
bos@559 1084 found <literal>lighttpd</literal> to be noticeably easier to
bos@559 1085 configure than Apache, even though I've used Apache for over
bos@559 1086 a decade, and this was my first exposure to
bos@559 1087 <literal>lighttpd</literal>.</para>
bos@559 1088
bos@559 1089 </sect3>
bos@559 1090 </sect2>
bos@559 1091 <sect2>
bos@559 1092 <title>Sharing multiple repositories with one CGI script</title>
bos@559 1093
bos@584 1094 <para id="x_4d4">The <filename role="special">hgweb.cgi</filename> script
bos@559 1095 only lets you publish a single repository, which is an
bos@559 1096 annoying restriction. If you want to publish more than one
bos@559 1097 without wracking yourself with multiple copies of the same
bos@559 1098 script, each with different names, a better choice is to use
bos@559 1099 the <filename role="special">hgwebdir.cgi</filename>
bos@559 1100 script.</para>
bos@559 1101
bos@584 1102 <para id="x_4d5">The procedure to configure <filename
bos@559 1103 role="special">hgwebdir.cgi</filename> is only a little more
bos@559 1104 involved than for <filename
bos@559 1105 role="special">hgweb.cgi</filename>. First, you must obtain
bos@559 1106 a copy of the script. If you don't have one handy, you can
bos@559 1107 download a copy from the master Mercurial repository at <ulink
bos@559 1108 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 1109
bos@584 1110 <para id="x_4d6">You'll need to copy this script into your <filename
bos@559 1111 class="directory">public_html</filename> directory, and
bos@559 1112 ensure that it's executable.</para>
bos@580 1113 <programlisting>cp .../hgwebdir.cgi ~/public_html
bos@580 1114 chmod 755 ~/public_html ~/public_html/hgwebdir.cgi</programlisting>
bos@584 1115 <para id="x_4d7">With basic configuration out of the way, try to visit
bos@559 1116 <ulink url="http://myhostname/
bos@559 1117 myuser/hgwebdir.cgi">http://myhostname/
bos@559 1118 myuser/hgwebdir.cgi</ulink> in your browser. It should
bos@559 1119 display an empty list of repositories. If you get a blank
bos@559 1120 window or error message, try walking through the list of
bos@559 1121 potential problems in section <xref
bos@559 1122 linkend="sec:collab:wtf"/>.</para>
bos@559 1123
bos@584 1124 <para id="x_4d8">The <filename role="special">hgwebdir.cgi</filename>
bos@559 1125 script relies on an external configuration file. By default,
bos@559 1126 it searches for a file named <filename
bos@559 1127 role="special">hgweb.config</filename> in the same directory
bos@559 1128 as itself. You'll need to create this file, and make it
bos@559 1129 world-readable. The format of the file is similar to a
bos@559 1130 Windows <quote>ini</quote> file, as understood by Python's
bos@559 1131 <literal>ConfigParser</literal>
bos@559 1132 <citation>web:configparser</citation> module.</para>
bos@559 1133
bos@584 1134 <para id="x_4d9">The easiest way to configure <filename
bos@559 1135 role="special">hgwebdir.cgi</filename> is with a section
bos@559 1136 named <literal>collections</literal>. This will automatically
bos@559 1137 publish <emphasis>every</emphasis> repository under the
bos@559 1138 directories you name. The section should look like
bos@559 1139 this:</para>
bos@580 1140 <programlisting>[collections]
bos@580 1141 /my/root = /my/root</programlisting>
bos@584 1142 <para id="x_4da">Mercurial interprets this by looking at the directory name
bos@559 1143 on the <emphasis>right</emphasis> hand side of the
bos@559 1144 <quote><literal>=</literal></quote> sign; finding repositories
bos@559 1145 in that directory hierarchy; and using the text on the
bos@559 1146 <emphasis>left</emphasis> to strip off matching text from the
bos@559 1147 names it will actually list in the web interface. The
bos@559 1148 remaining component of a path after this stripping has
bos@559 1149 occurred is called a <quote>virtual path</quote>.</para>
bos@559 1150
bos@584 1151 <para id="x_4db">Given the example above, if we have a repository whose
bos@559 1152 local path is <filename
bos@559 1153 class="directory">/my/root/this/repo</filename>, the CGI
bos@559 1154 script will strip the leading <filename
bos@559 1155 class="directory">/my/root</filename> from the name, and
bos@559 1156 publish the repository with a virtual path of <filename
bos@559 1157 class="directory">this/repo</filename>. If the base URL for
bos@559 1158 our CGI script is <ulink url="http://myhostname/
bos@559 1159 myuser/hgwebdir.cgi">http://myhostname/
bos@559 1160 myuser/hgwebdir.cgi</ulink>, the complete URL for that
bos@559 1161 repository will be <ulink url="http://myhostname/
bos@559 1162 myuser/hgwebdir.cgi/this/repo">http://myhostname/
bos@559 1163 myuser/hgwebdir.cgi/this/repo</ulink>.</para>
bos@559 1164
bos@584 1165 <para id="x_4dc">If we replace <filename
bos@559 1166 class="directory">/my/root</filename> on the left hand side
bos@559 1167 of this example with <filename
bos@559 1168 class="directory">/my</filename>, then <filename
bos@559 1169 role="special">hgwebdir.cgi</filename> will only strip off
bos@559 1170 <filename class="directory">/my</filename> from the repository
bos@559 1171 name, and will give us a virtual path of <filename
bos@559 1172 class="directory">root/this/repo</filename> instead of
bos@559 1173 <filename class="directory">this/repo</filename>.</para>
bos@559 1174
bos@584 1175 <para id="x_4dd">The <filename role="special">hgwebdir.cgi</filename>
bos@559 1176 script will recursively search each directory listed in the
bos@559 1177 <literal>collections</literal> section of its configuration
bos@559 1178 file, but it will <literal>not</literal> recurse into the
bos@559 1179 repositories it finds.</para>
bos@559 1180
bos@584 1181 <para id="x_4de">The <literal>collections</literal> mechanism makes it easy
bos@559 1182 to publish many repositories in a <quote>fire and
bos@559 1183 forget</quote> manner. You only need to set up the CGI
bos@559 1184 script and configuration file one time. Afterwards, you can
bos@559 1185 publish or unpublish a repository at any time by simply moving
bos@559 1186 it into, or out of, the directory hierarchy in which you've
bos@559 1187 configured <filename role="special">hgwebdir.cgi</filename> to
bos@559 1188 look.</para>
bos@559 1189
bos@559 1190 <sect3>
bos@559 1191 <title>Explicitly specifying which repositories to
bos@559 1192 publish</title>
bos@559 1193
bos@584 1194 <para id="x_4df">In addition to the <literal>collections</literal>
bos@559 1195 mechanism, the <filename
bos@559 1196 role="special">hgwebdir.cgi</filename> script allows you
bos@559 1197 to publish a specific list of repositories. To do so,
bos@559 1198 create a <literal>paths</literal> section, with contents of
bos@559 1199 the following form.</para>
bos@580 1200 <programlisting>[paths]
bos@580 1201 repo1 = /my/path/to/some/repo
bos@580 1202 repo2 = /some/path/to/another</programlisting>
bos@584 1203 <para id="x_4e0">In this case, the virtual path (the component that will
bos@559 1204 appear in a URL) is on the left hand side of each
bos@559 1205 definition, while the path to the repository is on the
bos@559 1206 right. Notice that there does not need to be any
bos@559 1207 relationship between the virtual path you choose and the
bos@559 1208 location of a repository in your filesystem.</para>
bos@559 1209
bos@584 1210 <para id="x_4e1">If you wish, you can use both the
bos@559 1211 <literal>collections</literal> and <literal>paths</literal>
bos@559 1212 mechanisms simultaneously in a single configuration
bos@559 1213 file.</para>
bos@559 1214
bos@559 1215 <note>
bos@584 1216 <para id="x_4e2"> If multiple repositories have the same virtual path,
bos@559 1217 <filename role="special">hgwebdir.cgi</filename> will not
bos@559 1218 report an error. Instead, it will behave
bos@559 1219 unpredictably.</para>
bos@559 1220 </note>
bos@559 1221
bos@559 1222 </sect3>
bos@559 1223 </sect2>
bos@559 1224 <sect2>
bos@559 1225 <title>Downloading source archives</title>
bos@559 1226
bos@584 1227 <para id="x_4e3">Mercurial's web interface lets users download an archive
bos@559 1228 of any revision. This archive will contain a snapshot of the
bos@559 1229 working directory as of that revision, but it will not contain
bos@559 1230 a copy of the repository data.</para>
bos@559 1231
bos@584 1232 <para id="x_4e4">By default, this feature is not enabled. To enable it,
bos@559 1233 you'll need to add an <envar
bos@559 1234 role="rc-item-web">allow_archive</envar> item to the
bos@559 1235 <literal role="rc-web">web</literal> section of your <filename
bos@580 1236 role="special">~/.hgrc</filename>.</para>
bos@559 1237
bos@559 1238 </sect2>
bos@559 1239 <sect2>
bos@559 1240 <title>Web configuration options</title>
bos@559 1241
bos@584 1242 <para id="x_4e5">Mercurial's web interfaces (the <command role="hg-cmd">hg
bos@559 1243 serve</command> command, and the <filename
bos@559 1244 role="special">hgweb.cgi</filename> and <filename
bos@559 1245 role="special">hgwebdir.cgi</filename> scripts) have a
bos@559 1246 number of configuration options that you can set. These
bos@559 1247 belong in a section named <literal
bos@559 1248 role="rc-web">web</literal>.</para>
bos@559 1249 <itemizedlist>
bos@584 1250 <listitem><para id="x_4e6"><envar
bos@559 1251 role="rc-item-web">allow_archive</envar>: Determines
bos@559 1252 which (if any) archive download mechanisms Mercurial
bos@559 1253 supports. If you enable this feature, users of the web
bos@559 1254 interface will be able to download an archive of whatever
bos@559 1255 revision of a repository they are viewing. To enable the
bos@559 1256 archive feature, this item must take the form of a
bos@559 1257 sequence of words drawn from the list below.</para>
bos@559 1258 <itemizedlist>
bos@584 1259 <listitem><para id="x_4e7"><literal>bz2</literal>: A
bos@559 1260 <command>tar</command> archive, compressed using
bos@559 1261 <literal>bzip2</literal> compression. This has the
bos@559 1262 best compression ratio, but uses the most CPU time on
bos@559 1263 the server.</para>
bos@559 1264 </listitem>
bos@584 1265 <listitem><para id="x_4e8"><literal>gz</literal>: A
bos@559 1266 <command>tar</command> archive, compressed using
bos@559 1267 <literal>gzip</literal> compression.</para>
bos@559 1268 </listitem>
bos@584 1269 <listitem><para id="x_4e9"><literal>zip</literal>: A
bos@559 1270 <command>zip</command> archive, compressed using LZW
bos@559 1271 compression. This format has the worst compression
bos@559 1272 ratio, but is widely used in the Windows world.</para>
bos@559 1273 </listitem>
bos@559 1274 </itemizedlist>
bos@584 1275 <para id="x_4ea"> If you provide an empty list, or don't have an
bos@559 1276 <envar role="rc-item-web">allow_archive</envar> entry at
bos@559 1277 all, this feature will be disabled. Here is an example of
bos@559 1278 how to enable all three supported formats.</para>
bos@580 1279 <programlisting>[web]
bos@580 1280 allow_archive = bz2 gz zip</programlisting>
bos@559 1281 </listitem>
bos@584 1282 <listitem><para id="x_4eb"><envar role="rc-item-web">allowpull</envar>:
bos@559 1283 Boolean. Determines whether the web interface allows
bos@559 1284 remote users to <command role="hg-cmd">hg pull</command>
bos@559 1285 and <command role="hg-cmd">hg clone</command> this
bos@559 1286 repository over HTTP. If set to <literal>no</literal> or
bos@559 1287 <literal>false</literal>, only the
bos@559 1288 <quote>human-oriented</quote> portion of the web interface
bos@559 1289 is available.</para>
bos@559 1290 </listitem>
bos@584 1291 <listitem><para id="x_4ec"><envar role="rc-item-web">contact</envar>:
bos@559 1292 String. A free-form (but preferably brief) string
bos@559 1293 identifying the person or group in charge of the
bos@559 1294 repository. This often contains the name and email
bos@559 1295 address of a person or mailing list. It often makes sense
bos@559 1296 to place this entry in a repository's own <filename
bos@559 1297 role="special">.hg/hgrc</filename> file, but it can make
bos@580 1298 sense to use in a global <filename
bos@580 1299 role="special">~/.hgrc</filename> if every repository
bos@580 1300 has a single maintainer.</para>
bos@559 1301 </listitem>
bos@584 1302 <listitem><para id="x_4ed"><envar role="rc-item-web">maxchanges</envar>:
bos@559 1303 Integer. The default maximum number of changesets to
bos@559 1304 display in a single page of output.</para>
bos@559 1305 </listitem>
bos@584 1306 <listitem><para id="x_4ee"><envar role="rc-item-web">maxfiles</envar>:
bos@559 1307 Integer. The default maximum number of modified files to
bos@559 1308 display in a single page of output.</para>
bos@559 1309 </listitem>
bos@584 1310 <listitem><para id="x_4ef"><envar role="rc-item-web">stripes</envar>:
bos@559 1311 Integer. If the web interface displays alternating
bos@559 1312 <quote>stripes</quote> to make it easier to visually align
bos@559 1313 rows when you are looking at a table, this number controls
bos@559 1314 the number of rows in each stripe.</para>
bos@559 1315 </listitem>
bos@584 1316 <listitem><para id="x_4f0"><envar role="rc-item-web">style</envar>:
bos@559 1317 Controls the template Mercurial uses to display the web
bos@559 1318 interface. Mercurial ships with two web templates, named
bos@559 1319 <literal>default</literal> and <literal>gitweb</literal>
bos@559 1320 (the latter is much more visually attractive). You can
bos@559 1321 also specify a custom template of your own; see chapter
bos@559 1322 <xref linkend="chap:template"/> for details.
bos@559 1323 Here, you can see how to enable the
bos@559 1324 <literal>gitweb</literal> style.</para>
bos@580 1325 <programlisting>[web]
bos@580 1326 style = gitweb</programlisting>
bos@559 1327 </listitem>
bos@584 1328 <listitem><para id="x_4f1"><envar role="rc-item-web">templates</envar>:
bos@559 1329 Path. The directory in which to search for template
bos@559 1330 files. By default, Mercurial searches in the directory in
bos@559 1331 which it was installed.</para>
bos@559 1332 </listitem></itemizedlist>
bos@584 1333 <para id="x_4f2">If you are using <filename
bos@559 1334 role="special">hgwebdir.cgi</filename>, you can place a few
bos@559 1335 configuration items in a <literal role="rc-web">web</literal>
bos@559 1336 section of the <filename
bos@559 1337 role="special">hgweb.config</filename> file instead of a
bos@580 1338 <filename role="special">~/.hgrc</filename> file, for
bos@559 1339 convenience. These items are <envar
bos@559 1340 role="rc-item-web">motd</envar> and <envar
bos@559 1341 role="rc-item-web">style</envar>.</para>
bos@559 1342
bos@559 1343 <sect3>
bos@559 1344 <title>Options specific to an individual repository</title>
bos@559 1345
bos@584 1346 <para id="x_4f3">A few <literal role="rc-web">web</literal> configuration
bos@559 1347 items ought to be placed in a repository's local <filename
bos@559 1348 role="special">.hg/hgrc</filename>, rather than a user's
bos@580 1349 or global <filename role="special">~/.hgrc</filename>.</para>
bos@559 1350 <itemizedlist>
bos@584 1351 <listitem><para id="x_4f4"><envar
bos@559 1352 role="rc-item-web">description</envar>: String. A
bos@559 1353 free-form (but preferably brief) string that describes
bos@559 1354 the contents or purpose of the repository.</para>
bos@559 1355 </listitem>
bos@584 1356 <listitem><para id="x_4f5"><envar role="rc-item-web">name</envar>:
bos@559 1357 String. The name to use for the repository in the web
bos@559 1358 interface. This overrides the default name, which is
bos@559 1359 the last component of the repository's path.</para>
bos@559 1360 </listitem></itemizedlist>
bos@559 1361
bos@559 1362 </sect3>
bos@559 1363 <sect3>
bos@559 1364 <title>Options specific to the <command role="hg-cmd">hg
bos@559 1365 serve</command> command</title>
bos@559 1366
bos@584 1367 <para id="x_4f6">Some of the items in the <literal
bos@559 1368 role="rc-web">web</literal> section of a <filename
bos@580 1369 role="special">~/.hgrc</filename> file are only for use
bos@559 1370 with the <command role="hg-cmd">hg serve</command>
bos@559 1371 command.</para>
bos@559 1372 <itemizedlist>
bos@584 1373 <listitem><para id="x_4f7"><envar role="rc-item-web">accesslog</envar>:
bos@559 1374 Path. The name of a file into which to write an access
bos@559 1375 log. By default, the <command role="hg-cmd">hg
bos@559 1376 serve</command> command writes this information to
bos@559 1377 standard output, not to a file. Log entries are written
bos@559 1378 in the standard <quote>combined</quote> file format used
bos@559 1379 by almost all web servers.</para>
bos@559 1380 </listitem>
bos@584 1381 <listitem><para id="x_4f8"><envar role="rc-item-web">address</envar>:
bos@559 1382 String. The local address on which the server should
bos@559 1383 listen for incoming connections. By default, the server
bos@559 1384 listens on all addresses.</para>
bos@559 1385 </listitem>
bos@584 1386 <listitem><para id="x_4f9"><envar role="rc-item-web">errorlog</envar>:
bos@559 1387 Path. The name of a file into which to write an error
bos@559 1388 log. By default, the <command role="hg-cmd">hg
bos@559 1389 serve</command> command writes this information to
bos@559 1390 standard error, not to a file.</para>
bos@559 1391 </listitem>
bos@584 1392 <listitem><para id="x_4fa"><envar role="rc-item-web">ipv6</envar>:
bos@559 1393 Boolean. Whether to use the IPv6 protocol. By default,
bos@559 1394 IPv6 is not used.</para>
bos@559 1395 </listitem>
bos@584 1396 <listitem><para id="x_4fb"><envar role="rc-item-web">port</envar>:
bos@559 1397 Integer. The TCP port number on which the server should
bos@559 1398 listen. The default port number used is 8000.</para>
bos@559 1399 </listitem></itemizedlist>
bos@559 1400
bos@559 1401 </sect3>
bos@559 1402 <sect3>
bos@580 1403 <title>Choosing the right <filename
bos@580 1404 role="special">~/.hgrc</filename> file to add <literal
bos@559 1405 role="rc-web">web</literal> items to</title>
bos@559 1406
bos@584 1407 <para id="x_4fc">It is important to remember that a web server like
bos@559 1408 Apache or <literal>lighttpd</literal> will run under a user
bos@559 1409 ID that is different to yours. CGI scripts run by your
bos@559 1410 server, such as <filename
bos@559 1411 role="special">hgweb.cgi</filename>, will usually also run
bos@559 1412 under that user ID.</para>
bos@559 1413
bos@584 1414 <para id="x_4fd">If you add <literal role="rc-web">web</literal> items to
bos@580 1415 your own personal <filename role="special">~/.hgrc</filename> file, CGI scripts won't read that
bos@580 1416 <filename role="special">~/.hgrc</filename> file. Those
bos@559 1417 settings will thus only affect the behaviour of the <command
bos@559 1418 role="hg-cmd">hg serve</command> command when you run it.
bos@559 1419 To cause CGI scripts to see your settings, either create a
bos@580 1420 <filename role="special">~/.hgrc</filename> file in the
bos@559 1421 home directory of the user ID that runs your web server, or
bos@559 1422 add those settings to a system-wide <filename
bos@580 1423 role="special">~/.hgrc</filename> file.</para>
bos@559 1424
bos@559 1425
bos@559 1426 </sect3>
bos@559 1427 </sect2>
bos@559 1428 </sect1>
bos@559 1429 </chapter>
bos@559 1430
bos@559 1431 <!--
bos@559 1432 local variables:
bos@559 1433 sgml-parent-document: ("00book.xml" "book" "chapter")
bos@559 1434 end:
bos@559 1435 -->