Changes between Version 2 and Version 3 of TracPlugins


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Timestamp:
Dec 25, 2018, 9:20:53 PM (6 years ago)
Author:
trac
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  • TracPlugins

    v2 v3  
    77== Plugin discovery
    88
    9 From the user's point of view, a plugin is either a standalone .py file or an .egg package. Trac looks for plugins in Python's `site-packages` directory, the [TracIni#GlobalConfiguration global shared] `plugins` directory and the [TracEnvironment project environment] `plugins` directory. Components defined in globally-installed plugins must be explicitly enabled in the [[TracIni#components-section| [components] ]] section of the `trac.ini` file. Components defined in the `plugins` directory of the project environment are enabled, unless explicitly disabled in the `[components]` section of the `trac.ini` file.
    10 
    11 == Requirements for Trac eggs #Requirements
    12 
    13 To use egg-based plugins in Trac, you need to have [http://peak.telecommunity.com/DevCenter/setuptools setuptools] (version >= 0.6) installed.
    14 
    15 To install `setuptools`, download the bootstrap module [http://peak.telecommunity.com/dist/ez_setup.py ez_setup.py] and execute it as follows:
    16 
    17 {{{#!sh
    18 $ python ez_setup.py
    19 }}}
    20 
    21 If the `ez_setup.py` script fails to install the setuptools release, you can download it from [pypi:setuptools PyPI] and install it manually.
    22 
    23 Plugins can also consist of a single `.py` file dropped directly into either the project's or the shared `plugins` directory.
     9From the user's point of view, a plugin is either a standalone .py file or a package (egg or wheel). Trac looks for plugins in Python's `site-packages` directory, the [TracIni#GlobalConfiguration global shared] `plugins` directory and the [TracEnvironment project environment] `plugins` directory. Components defined in globally-installed plugins must be explicitly enabled in the [[TracIni#components-section| [components] ]] section of the `trac.ini` file. Components defined in the `plugins` directory of the project environment are enabled, unless explicitly disabled in the `[components]` section of the `trac.ini` file.
    2410
    2511== Installing a Trac plugin
    … …  
    3925You should now have an *.egg file. Examine the output of running Python to find where this was created.
    4026
    41 Once you have the plugin archive, 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. If you are running as a [wiki:TracStandalone "tracd" standalone server], restart tracd, ie kill the process and run again.
     27Once you have the plugin archive, copy it into the `plugins` directory of the [TracEnvironment project environment]. Also, make sure that the web server has sufficient permissions to read the plugin egg. Then restart the web server. If you are running as a [TracStandalone "tracd" standalone server], restart tracd, ie kill the process and run again.
    4228
    4329To uninstall a plugin installed this way, remove the egg from the `plugins` directory and restart the web server.
    … …  
    5440{{{#!sh
    5541$ easy_install TracTags
     42}}}
     43{{{#!sh
    5644$ pip install TracTags
    5745}}}
    5846
    59 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:\Python27\Scripts`) to their `PATH` environment variable, or use the full path to `easy_install` (for example, `C:\Python27\Scripts\easy_install.py`). See [http://peak.telecommunity.com/DevCenter/EasyInstall#windows-notes easy_install Windows notes] for more information.
     47If `easy_install` is not on your system, see the [trac:setuptools#Installsetuptools Trac setuptools documentation].
    6048
    6149`pip` is included in Python 2.7.9. In earlier versions of Python it can be installed through the package manager of your OS (e.g. `apt-get install python-pip`) or using the [https://pip.pypa.io/en/latest/installing.html#install-pip get_pip.py].
    … …  
    7159==== From source
    7260
    73 `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:
     61`easy_install` and `pip` make installing from source a snap. Just give it the URL to either a repository or a tarball/zip of the source:
    7462{{{#!sh
    7563$ easy_install https://trac-hacks.org/svn/tagsplugin/trunk
    7664}}}
     65{{{#!sh
     66$ pip install svn+https://trac-hacks.org/svn/tagsplugin/trunk
     67}}}
     68When installing from a repository using `pip`, be sure to use the repository type in the protocol. For example, `svn+https` for Subversion and `git+https` for Git.
    7769
    7870==== Enabling the plugin
    7971
    80 Unlike 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 the shared plugins directory, ie the path specified in the `[inherit] plugins_dir` configuration option.
    81 
    82 This is done in the `[components]` section of the configuration file `trac.ini`. For example:
     72Unlike plugins installed per environment, you'll have to explicitly enable globally installed plugins via [TracIni trac.ini]. This also applies to plugins installed in the shared plugins directory, ie the path specified in the [TracIni#inherit-plugins_dir-option "[inherit] plugins_dir"] configuration option.
     73
     74This is done in the [TracIni#components-section "[components]"] section of the configuration file `trac.ini`. For example:
    8375{{{#!ini
    8476[components]
    … …  
    10092A database backup will be made before upgrading the environment, unless the `--no-backup` option is specified. For more information, refer to the documentation output by `trac-admin /path/to/env help upgrade`.
    10193
     94==== Redeploying static resources
     95
     96If you [TracInstall#MappingStaticResources mapped static resources] so they are served by the web server, and the plugin contains static resources (CSS, !JavaScript and image files), the resources will need to be deployed to the location on the filesystem that is served by the web server.
     97
     98Execute the `deploy` command, as was done during install and [TracUpgrade#a5.Refreshstaticresources upgrade]:
     99
     100{{{#!sh
     101$ trac-admin /path/to/env deploy /deploy/path
     102}}}
     103
     104After executing the command, you must restart your web server.
     105
     106{{{#!div style="border: 1pt dotted; margin: 1em"
     107**Note:** Some web browsers (IE, Opera) cache CSS and Javascript files, so you should instruct your users to manually erase the contents of their browser's cache. A forced refreshed (SHIFT + <F5>) should be enough.
     108{{{#!comment
     109Remove above note once #9936 is fixed.
     110}}}
     111}}}
     112
     113==== Upgrading a Plugin
     114
     115Normally, upgrading a plugin is simply a matter of repeating the install process. You may want to [#Uninstalling uninstall] old versions of the plugin.
     116
     117The `pip install` command has an `--upgrade (-U)` switch that will uninstall the old version and install the new version. The command can have some unintended side-effects though, because it will also upgrade the plugin dependencies. For example, if `Trac` is listed as a dependency of the plugin in `setup.py`, the latest version of Trac will be downloaded and installed. This may not be what you want if you are running an older version of Trac because not all your plugins are compatible with the latest version of Trac, or you simply haven't done the appropriate planning for upgrading Trac. Uninstalling and then installing the plugin can be a safer option:
     118{{{#!sh
     119$ pip uninstall <pluginname>
     120$ pip install <pluginname>
     121}}}
     122
     123Alternatively you can use a [https://pip.pypa.io/en/stable/user_guide/#requirements-files requirements file] and pin the versions of the packages that you don't want to implicitly upgrade.
     124
    102125==== Uninstalling
    103126
     127`pip` makes it easy to uninstall a plugin:
     128{{{#!sh
     129$ pip uninstall <pluginname>
     130}}}
     131
     132The `pip uninstall` command can be used even if the plugin was installed using `easy_install` or `python setup.py install`.
     133
    104134Neither `easy_install` nor `python setup.py` have an uninstall feature. However, it is usually trivial to remove a globally installed egg and reference:
    105135
    106  1. Do `easy_install -m [plugin name]` to remove references from `$PYTHONLIB/site-packages/easy-install.pth` when the plugin installed by setuptools.
     136 1. Do `easy_install -m <plugin name>` to remove references from `$PYTHONLIB/site-packages/easy-install.pth` when the plugin is installed by setuptools.
    107137 1. Delete executables from `/usr/bin`, `/usr/local/bin`, or `C:\\Python*\Scripts`. To find what executables are involved, refer to the `[console-script]` section of `setup.py`.
    108138 1. Delete the .egg file or folder from where it's installed, usually inside `$PYTHONLIB/site-packages/`.
    … …  
    118148== Setting up the plugin cache
    119149
    120 Some plugins will need to be extracted by the Python egg's 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.
    121 
    122 To do this from the Apache configuration, use the `SetEnv` directive:
    123 {{{#!apache
    124 SetEnv PYTHON_EGG_CACHE /path/to/dir
    125 }}}
    126 
    127 This works whether you're using the [wiki:TracCgi CGI] or the [wiki:TracModPython mod_python] front-end. Put this directive next to where you set the path to the [wiki:TracEnvironment Trac environment], ie in the same `<Location>` block.
    128 
    129 For example for CGI:
    130 {{{#!apache
    131  <Location /trac>
    132    SetEnv TRAC_ENV /path/to/projenv
    133    SetEnv PYTHON_EGG_CACHE /path/to/dir
    134  </Location>
    135 }}}
    136 
    137 Or for mod_python:
    138 {{{#!apache
    139  <Location /trac>
    140    SetHandler mod_python
    141    ...
    142    SetEnv PYTHON_EGG_CACHE /path/to/dir
    143  </Location>
    144 }}}
    145 
    146 '''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.
    147 
    148 For [wiki:TracFastCgi FastCGI], you'll need to `-initial-env` option, or whatever is provided by your web server for setting environment variables.
    149 
    150 '''Note''': 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:
    151 
    152 {{{#!apache
    153 FastCgiConfig -initial-env TRAC_ENV=/var/lib/trac -initial-env PYTHON_EGG_CACHE=/var/lib/trac/plugin-cache
    154 }}}
    155 
    156 === About hook scripts
    157 
    158 If you have set up some Subversion hook scripts that call the Trac engine, such as the post-commit hook script provided in the `/contrib` directory, make sure you define the `PYTHON_EGG_CACHE` environment variable within these scripts as well.
     150Some plugins will need to be extracted by the Python egg's runtime. See [wiki:TracInstall#egg-cache] for information on setting up the egg cache.
    159151
    160152== Web-based plugin administration
    161153
    162 The [trac:WebAdmin] interface offers limited support for plugin configuration through the web to users with `TRAC_ADMIN` permission:
    163 
    164 * en/disabling installed plugins
     154The !WebAdmin interface offers limited support for plugin configuration to users with `TRAC_ADMIN` permission:
     155
     156* enabling and disabling installed plugins
    165157* installing plugins by uploading them as eggs
    166158
    … …  
    172164This disables the whole panel, so the first function will no longer be available either.
    173165
     166== Writing Trac Plugins
     167
     168You can write your own Trac plugin using the following resources:
     169* [trac:TracDev Developer documentation]
     170* [https://trac-hacks.org Examples on trac-hacks.org]
     171* [trac:browser:branches/1.2-stable/sample-plugins sample-plugins]
     172
    174173== Troubleshooting
    175174
    … …  
    204203=== Check the log files
    205204
    206 Enable [wiki:TracLogging logging] and set the log level to `DEBUG`, then watch the log file for messages about loading plugins.
     205Enable [TracLogging logging] and set the log level to `DEBUG`, then watch the log file for messages about loading plugins.
    207206
    208207=== Verify you have the proper permissions
    209208
    210 Some 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.
     209Some 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.
    211210
    212211=== Is the wrong version of the plugin loading?
    213212
    214 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 some basic rules:
     213If you put your plugins inside the `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:
    215214
    216215 * 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.
    … …  
    221220=== If all of the above failed
    222221
    223 Okay, 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 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!
     222Okay, 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 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] or [trac:MailingList] and ask away!
    224223
    225224----