Changes between Version 1 and Version 2 of TracPlugins


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Timestamp:
02/08/11 21:48:17 (10 years ago)
Author:
trac (IP: 127.0.0.1)
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  • TracPlugins

    v1 v2  
    22[[TracGuideToc]]
    33
    4 Since version 0.9, Trac supports plugins that extend the built-in functionality. The plugin functionality is based on the [http://trac.edgewall.org/wiki/TracDev/ComponentArchitecture component architecture].
     4Since version 0.9, Trac supports [trac:PluginList plugins] that extend the built-in functionality. The plugin functionality is based on the [trac:TracDev/ComponentArchitecture component architecture].
     5
     6Plugins can be either installed globally, in a shared plugins directory  (see [TracIni#GlobalConfiguration Global Configuration]) or locally for specific TracEnvironment, in its `plugins` directory.
     7Except for the later case, the components defined in a plugin should be explicitly enabled in the [[TracIni#components-section| [components] ]] section of the trac.ini file.
    58
    69== Requirements ==
     
    1518If the `ez_setup.py` script fails to install the setuptools release, you can download it from [http://www.python.org/pypi/setuptools PyPI] and install it manually.
    1619
    17 Plugins can also consist of a single `.py` file dropped into either the environment or global `plugins` directory ''(since [milestone:0.10])''.
     20Plugins can also consist of a single `.py` file dropped into either the environment or the shared plugins directory.
    1821
    1922== Installing a Trac Plugin ==
     
    3235Then you will have a *.egg file. Examine the output of running python to find where this was created.
    3336
    34 Once you have the plugin archive, you need to copy it into the `plugins` directory of the [wiki:TracEnvironment project environment]. Also, make sure that the web server has sufficient permissions to read the plugin egg.
     37Once you have the plugin archive, you need to copy it into the `plugins` directory of the [wiki:TracEnvironment project environment]. Also, make sure that the web server has sufficient permissions to read the plugin egg. Then, restart the web server (this requirement was not previously mentioned in this document, but in my tests it began working only after I did so).
     38
     39To uninstall a plugin installed this way, remove the egg from `plugins` directory and restart web server.
    3540
    3641Note that the Python version that the egg is built with must
    3742match the Python version with which Trac is run.  If for
    38 instance you are running Trac under Python 2.3, but have
    39 upgraded your standalone Python to 2.4, the eggs won't be
     43instance you are running Trac under Python 2.5, but have
     44upgraded your standalone Python to 2.6, the eggs won't be
    4045recognized.
     46
     47Note also that in a multi-project setup, a pool of Python interpreter instances will be dynamically allocated to projects based on need, and since plugins occupy a place in Python's module system, the first version of any given plugin to be loaded will be used for all the projects. In other words, you cannot use different versions of a single plugin in two projects of a multi-project setup. It may be safer to install plugins for all projects (see below) and then enable them selectively on a project-by-project basis.
    4148
    4249=== For All Projects ===
     
    4451==== With an .egg file ====
    4552
    46 Some plugins (such as [http://trac.edgewall.org/wiki/SpamFilter SpamFilter]) are downloadable as a `.egg` file which can be installed with the `easy_install` program:
     53Some plugins (such as [trac:SpamFilter SpamFilter]) are downloadable as a `.egg` file which can be installed with the `easy_install` program:
    4754{{{
    4855easy_install TracSpamFilter
    4956}}}
    5057
    51 If `easy_install` is not on your system see the Requirements section above to install it.  Windows users will need to add the `Scripts` directory of their Python installation (for example, `C:\Python23\Scripts`) to their `PATH` environment variable (see [http://peak.telecommunity.com/DevCenter/EasyInstall#windows-notes easy_install Windows notes] for more information).
     58If `easy_install` is not on your system see the Requirements section above to install it.  Windows users will need to add the `Scripts` directory of their Python installation (for example, `C:\Python24\Scripts`) to their `PATH` environment variable (see [http://peak.telecommunity.com/DevCenter/EasyInstall#windows-notes easy_install Windows notes] for more information).
    5259
    5360If Trac reports permission errors after installing a zipped egg and you would rather not bother providing a egg cache directory writable by the web server, you can get around it by simply unzipping the egg. Just pass `--always-unzip` to `easy_install`:
     
    5764You should end up with a directory having the same name as the zipped egg (complete with `.egg` extension) and containing its uncompressed contents.
    5865
    59 Trac also searches for globally installed plugins under `$PREFIX/share/trac/plugins` ''(since 0.10)''.
     66Trac also searches for plugins installed in the shared plugins directory ''(since 0.10)'', see TracIni#GlobalConfiguration. This is a convenient way to share the installation of plugins across several but not all environments.
    6067
    6168==== From source ====
     
    6370`easy_install` makes installing from source a snap. Just give it the URL to either a Subversion repository or a tarball/zip of the source:
    6471{{{
    65 easy_install http://svn.edgewall.com/repos/trac/sandbox/spam-filter
     72easy_install http://svn.edgewall.com/repos/trac/plugins/0.11/spam-filter
    6673}}}
    6774
    6875==== Enabling the plugin ====
    69 Unlike plugins installed per-environment, you'll have to explicitly enable globally installed plugins via [wiki:TracIni trac.ini]. This is done in the `[components]` section of the configuration file, for example:
     76Unlike plugins installed per-environment, you'll have to explicitly enable globally installed plugins via [wiki:TracIni trac.ini]. This also applies to plugins installed in shared plugins directory, i.e. the path specified in the `[inherit] plugins_dir` configuration option.
     77
     78This is done in the `[components]` section of the configuration file, for example:
    7079{{{
    7180[components]
     
    7786Note: After installing the plugin, you need to restart your web server.
    7887
     88==== Uninstalling ====
     89
     90`easy_install` or `python setup.py` does not have an uninstall feature. Hower, it is usually quite trivial to remove a globally installed egg and reference:
     91 1. Do `easy_install -m [plugin name]` to remove references from `$PYTHONLIB/site-packages/easy-install.pth` when the plugin installed by setuptools.
     92 1. Delete executables from `/usr/bin`, `/usr/local/bin` or `C:\\Python*\Scripts`. For search what executables are there, you may refer to `[console-script]` section of `setup.py`.
     93 1. Delete the .egg file or folder from where it is installed, usually inside `$PYTHONLIB/site-packages/`.
     94 1. Restart web server.
     95
     96If you are uncertain about the location of the egg, here is a small tip to help locate an egg (or any package) - replace `myplugin` with whatever namespace the plugin uses (as used when enabling the plugin):
     97{{{
     98>>> import myplugin
     99>>> print myplugin.__file__
     100/opt/local/python24/lib/site-packages/myplugin-0.4.2-py2.4.egg/myplugin/__init__.pyc
     101}}}
     102
    79103== Setting up the Plugin Cache ==
    80104
    81 Some plugins will need to be extracted by the Python eggs runtime (`pkg_resources`), so that their contents are actual files on the file system. The directory in which they are extracted defaults to the home directory of the current user, which may or may not be a problem. You can however override the default location using the `PYTHON_EGG_CACHE` environment variable.
     105Some plugins will need to be extracted by the Python eggs runtime (`pkg_resources`), so that their contents are actual files on the file system. The directory in which they are extracted defaults to '.python-eggs' in the home directory of the current user, which may or may not be a problem. You can however override the default location using the `PYTHON_EGG_CACHE` environment variable.
    82106
    83107To do this from the Apache configuration, use the `SetEnv` directive as follows:
     
    105129}}}
    106130
    107  ''Note: this requires the `mod_env` module''
     131 ''Note: !SetEnv requires the `mod_env` module which needs to be activated for Apache. In this case the !SetEnv directive can also be used in the `mod_python` Location block.''
    108132
    109133For [wiki:TracFastCgi FastCGI], you'll need to `-initial-env` option, or whatever is provided by your web server for setting environment variables.
    110134
    111  ''Note: that if you already use -initial-env to set the project directory for either a single project or parent you will need to add atleast one environment variable inside trac.fcgi as expressed in the example on [wiki:TracFastCgi TracFastCgi].
     135 ''Note: that if you already use -initial-env to set the project directory for either a single project or parent you will need to add an additional -initial-env directive to the !FastCgiConfig directive. I.e.
     136
     137{{{
     138FastCgiConfig -initial-env TRAC_ENV=/var/lib/trac -initial-env PYTHON_EGG_CACHE=/var/lib/trac/plugin-cache
     139}}}
    112140
    113141=== About hook scripts ===
     
    128156=== Did you get the correct version of the Python egg? ===
    129157
    130 Python eggs have the Python version encoded in their filename. For example, `MyPlugin-1.0-py2.4.egg` is an egg for Python 2.4, and will '''not''' be loaded if you're running a different Python version (such as 2.3 or 2.5).
     158Python eggs have the Python version encoded in their filename. For example, `MyPlugin-1.0-py2.5.egg` is an egg for Python 2.5, and will '''not''' be loaded if you're running a different Python version (such as 2.4 or 2.6).
    131159
    132160Also, verify that the egg file you downloaded is indeed a ZIP archive. If you downloaded it from a Trac site, chances are you downloaded the HTML preview page instead.
    133161
    134162=== Is the plugin enabled? ===
     163
    135164
    136165If you install a plugin globally (i.e. ''not'' inside the `plugins` directory of the Trac project environment) you will have to explicitly enable it in [TracIni trac.ini]. Make sure that:
     
    149178=== Verify you have proper permissions ===
    150179
    151 Some plugins require you have special permissions in order to use them. WebAdmin, for example, requires the user to have TRAC_ADMIN permissions for it to show up on the navigation bar.
     180Some plugins require you have special permissions in order to use them. [trac:WebAdmin WebAdmin], for example, requires the user to have TRAC_ADMIN permissions for it to show up on the navigation bar.
    152181
    153182=== Is the wrong version of the plugin loading? ===
    154183
    155 If you put your plugins inside plugins directories, and certainly if you have more than one project, you need to make sure that the correct version of the plugin is loading. Here are som basic rules:
     184If you put your plugins inside plugins directories, and certainly if you have more than one project, you need to make sure that the correct version of the plugin is loading. Here are some basic rules:
    156185 * Only one version of the plugin can be loaded for each running Trac server (ie. each Python process). The Python namespaces and module list will be shared, and it cannot handle duplicates. Whether a plugin is `enabled` or `disabled` makes no difference.
    157186 * A globally installed plugin (typically `setup.py install`) will override any version in global or project plugins directories. A plugin from the global plugins directory will be located before any project plugins directory.
     
    161190=== If all of the above failed ===
    162191
    163 OK, so the logs don't mention plugins, the egg is readable, the python version is correct ''and'' the egg has been installed globally (and is enabled in the trac.ini) and it still doesn't work or give any error messages or any other indication as to why? Hop on the IrcChannel and ask away.
     192OK, so the logs don't mention plugins, the egg is readable, the python version is correct ''and'' the egg has been installed globally (and is enabled in the trac.ini) and it still doesn't work or give any error messages or any other indication as to why? Hop on the [trac:IrcChannel IrcChannel] and ask away.
    164193
    165194----
    166 See also TracGuide, [http://trac.edgewall.org/wiki/PluginList plugin list], [http://trac.edgewall.org/wiki/TracDev/ComponentArchitecture component architecture]
     195See also TracGuide, [trac:PluginList plugin list], [trac:TracDev/ComponentArchitecture component architecture]