Repository hooks as pluggable extension points
The RepositoryHookSystemPlugin is designed to turn repository hooks, such as SVN's post-commit hook, into extension points so that arbitrary trac plugins may be built that have full access to the trac framework to act on repository commits.
- the RepositoryHookSystemPlugin provides an extension point (IRepositoryHookSubscriber) which may be populated with configurable hooks that have access to their trac environment
- the RepositoryHookSystemPlugin is able to enable and disable its presence in the SVN hooks directory without affecting other plugins
- the trac-post-commit-hook has been converted to a configurable plugin that does ticket changes (see source:repositoryhooksystemplugin/0.11/repository_hook_system/ticketchanger.py)
- has a webadmin interface for configuring hooks including figuring out whether or not the plugin has been enabled on a per-project basis
- plugins can be enabled on a per-hook basis
- the listeners are invoked via a command-line call from one of the repository hooks. This is a one-line command that passes whatever details are necessary to identify the changeset.
- a trac changeset object is used to pass around information. This is good, as it avoids unneccessary information to be sought by the RepositoryChangeListeners. For the SvnChangeListenerPlugin (at least as it stands living only in the post-commit hook), this is sufficient. It is unknown whether this is a good idea for other hooks and repository systems. A changeset object can be faked if it is not available (like it is at SVN post-commit).
- the logic of the RepositoryChangeListeners is agnostic to SCM type and hook used.
Architecture of the RepositoryHookSystemPlugin:
This is similar in concept to the SvnChangeListenerPlugin, but the architecture is also designed to support
- arbitrary version control systems, with an adapter for the version control system used to an implementation capable of hook invocation
- arbitrary hooks, not just post-commit
However, while architected to be arbitrary, this plugin has only been implemented for SVN.
If you are getting an error about PYTHON_EGG_CACHE not being set, then you may need to set this in your hook. See http://trac.edgewall.org/wiki/TracPlugins#Abouthookscripts
Download the zipped source from here.
Screenshot of the RepositoryHookSystemPlugin webadmin interface for configuration of an SVN post-commit hook:
Example of an SVN post-commit hook file generated by the RepositoryHookSystem that invokes the listener:
#!/bin/bash # trac repository hook system /home/jhammel/20080519133401/bin/python /home/jhammel/20080519133401/src/RepositoryHookSystem/repository_hook_system/listener.py -p /home/jhammel/20080519133401/projects/fooocracy -p /home/jhammel/20080519133401/projects/newproj --hook post-commit $2
Originally developed at The Open Planning Project