X-Git-Url: https://sipb.mit.edu/gitweb.cgi/ikiwiki.git/blobdiff_plain/74baaeba00c90cd7a027e40e2f6d65695341a0e1..HEAD:/doc/rcs/git.mdwn diff --git a/doc/rcs/git.mdwn b/doc/rcs/git.mdwn index eeb05d5f2..c82adbd04 100644 --- a/doc/rcs/git.mdwn +++ b/doc/rcs/git.mdwn @@ -1,7 +1,153 @@ -[[meta title="Git"]] +[[!meta title="Git"]] -[Git](http://git.or.cz) is a distributed revison control system originally developed for the Linux kernel. Ikiwiki supports storing a wiki in git. +[Git][git] is a distributed revison control system originally developed for +the Linux kernel. Ikiwiki supports storing a wiki in git. -Ikiwiki can run as a post-update hook to update a wiki whenever commits -come in. When running as a [[cgi]] with Git, ikiwiki automatically -commits edited pages, and uses the Git history to generate the [[RecentChanges]] page. \ No newline at end of file +[git]: http://git.or.cz/ + +Ikiwiki can run as a git `post-update` hook to update a wiki +whenever commits come in. When running as a [[cgi]], +ikiwiki automatically commits edited pages, and uses the +git history to generate the [[RecentChanges]] page. + +Normally you can just follow the instructions in [[setup]] to create +the git repositories and get started. To understand the details, read on. + +## git repository setup + +[[!img wiki_edit_flow.svg size=490x align=right]] + +The suggested setup for git has a bare repository, and various +working clones (with working directories). The bare +repository is pushed to and pulled from the various working clones. + +One of the clones is special; it is the srcdir +which is used to compile the wiki, and is also used by the +[[cgi]] to commit changes made via the web interface. It is special +since the `post-update` hook for the bare root repository is used to +trigger an update of this repository, and then an ikiwiki refresh +updates the published wiki itself. + +The other (optional) clones are meant for you to work +on, and commit to, changes should then be pushed to the bare root +repository. + +Using three or more repositories isn't the most obvious set up, but +it works the best for typical ikiwiki use. [[ikiwiki-makerepo]] can +automate setting this up for the common case where there is no +pre-existing wiki. [[tips/Laptop_wiki_with_git]] describes a different +way to set up ikiwiki and git. + +## git repository with multiple committers + +It can be tricky to get the permissions right to allow multiple people to +commit to an ikiwiki git repository. As the [[security]] page mentions, +for a secure ikiwiki installation, only one person should be able to write +to ikiwiki's srcdir. When other committers make commits, their commits +should be pushed to the bare repository, which has a `post-update` hook +that uses ikiwiki to pull the changes to the srcdir. + +One setup that will work is to put all committers in a group (say, +"ikiwiki"), and use permissions to allow that group to commit to the bare git +repository. Make both the post-update hook and ikiwiki.cgi be setgid +to the group, as well as suid to the user who admins the wiki. The +`wrappergroup` [[setup_file_option|usage]] can be used to make the wrappers +be setgid to the right group. Then the srcdir, including its git +repository, should only be writable by the wiki's admin, and *not* by the +group. Take care that ikiwiki uses a umask that does not cause files in +the srcdir to become group writable. (umask 022 will work.) + +## git repository with untrusted committers + +By default, anyone who can commit to the git repository can modify any file +on the wiki however they like. A `pre-receive` hook can be set up to limit +incoming commits from untrusted users. Then the same limits that are placed +on edits via the web will be in effect for commits to git for the users. +They will not be allowed to edit locked pages, they will only be able to +delete pages that the [[plugins/remove]] configuration allows them to +remove, and they will only be allowed to add non-page attachments that the +[[plugins/attachment]] configuration allows. + +To enable this, you need to set up the git repository to have multiple +committers. Trusted committers, including the user that ikiwiki runs as, +will not have their commits checked by the `pre-receive` hook. Untrusted +committers will have their commits checked. The configuration settings to +enable are `git_test_receive_wrapper`, which enables generation of a +`pre-receive` hook, and `untrusted_committers`, which is a list of +usernames of the untrusted committers. + +Note that when the `pre-receive` hook is checking incoming changes, it +ignores the git authorship information, and uses the username of the unix +user who made the commit. Then tests including the `locked_pages` +[[ikiwiki/PageSpec]] +are checked to see if that user can edit the pages in the commit. + +You can even set up an [[anonymous_user|tips/untrusted_git_push]], to allow +anyone to push changes in via git rather than using the web interface. + +## Optionally using a local wiki to preview changes + +When working on your wiki, +it is common (but optional) practice to preview your changes using a +private wiki on the local host before publishing the updates by +sending it to the root repository. If you do want to setup a private +wiki, you will have to have another setup file and and an ikiwiki +installation on your local machine. You will need all the packages +this implies -- a web server, git, ikiwiki, etc. However, there is a +_caveat_: by default, ikiwiki pulls and pushes from `origin`. This is +not ideal for the working clones on the local machine, since you might +go through several iterations of a page before pushing to the bare +root of the repository tree (and thus publishing it on your public wiki). +You do not want the action of refreshing the local wiki in order to +review your work to accidentally publish the +contents before you are ready. In order to prevent the git push that +is the normal behaviour of ikiwiki, set the configuration of the local wiki: + + gitorigin_branch => "", + ## git post-commit wrapper + git_wrapper => "/working/dir/.git/hooks/post-commit", + +Then just committing should refresh the private ikiwiki on the local +host. Now just run `ikiwiki -setup localwiki.setup -gettime` and +you should be good to go. (You only need the slow `-gettime` option +the first time you run setup.) Use standard git commands to handle +pulling from and pushing to the server. **Note**: After +pulling changes from the bare root repository, you will need to +manually update the local wiki, with a command such as `ikiwiki +-setup localwiki.setup -refresh`. You could use git's `post-merge` hook +to automate that command. + +## Using ikiwiki with Gerrit + +[Gerrit Code Review](https://code.google.com/p/gerrit/) manages a set of Git +repositories and provides a web interface to review and merge commits. You can +configure ikiwiki to work with a Gerrit-managed repository, allowing you to +review and merge commits to your wiki. + +First, create your initial wiki repository with Gerrit. On the server, as the +user that will own the wiki, clone that repository to create a working +directory for ikiwiki, such as /srv/wiki/ikiwiki-checkout. Create a setup file +and target directory as usual, referencing that working directory path, and +creating a post-update hook in Gerrit's repository. You'll need to set +appropriate permissions on the hook directory for the repository so that the +user running ikiwiki can compile and install the post-update hook. Also note +that you must disable web editing by disabling the editpage plugin, and you +must not enable any other plugin that commits to the repository, since ikiwiki +will not have permission to push to the repository. (Allowing web edits to +have such permission would bypass Gerrit's code review, defeating the purpose.) + +Gerrit does not run per-repository hooks, such as the post-update hook ikiwiki +installs to update the wiki after pushes. However, Gerrit has site-wide hooks, +including a ref-updated hook that runs whenever a ref changes. You can use +that hook to trigger ikiwiki's post-update hook. The following script, +installed as Gerrit's ref-updated hook, will run the post-update hook on any +repository that has a "gerrit-run-post-update-hook" file in it: + + #!/bin/sh + if [ -e "$GIT_DIR/gerrit-run-post-update-hook" ] ; then + exec "$GIT_DIR/hooks/post-update" + fi + +Then just create gerrit-run-post-update-hook in the wiki repository, run +ikiwiki --setup on the setup file, add your wiki to /etc/ikiwiki/wikilist, and +start reviewing and committing wiki changes via Gerrit.