Changes between Version 3 and Version 4 of Trac Mod Python


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Jun 10, 2015, 7:03:42 PM (9 years ago)
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trac
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  • Trac Mod Python

    v3 v4  
     1[[TracGuideToc]]
     2
    13= Trac and mod_python
    2 [[TracGuideToc]]
    34
    45Mod_python is an [https://httpd.apache.org/ Apache] module that embeds the Python interpreter within the server, so that web-based applications in Python will run many times faster than traditional CGI and will have the ability to retain database connections.
    … …  
    1213
    1314If you just installed mod_python, you may have to add a line to load the module in the Apache configuration:
    14 {{{
     15{{{#!apache
    1516LoadModule python_module modules/mod_python.so
    1617}}}
    1718
    18 ''Note: The exact path to the module depends on how the HTTPD installation is laid out.''
     19'''Note''': The exact path to the module depends on how the HTTPD installation is laid out.
    1920
    2021On Debian using apt-get:
    21 {{{
     22{{{#!sh
    2223apt-get install libapache2-mod-python libapache2-mod-python-doc
    2324}}}
     25
    2426Still on Debian, after you have installed mod_python, you must enable the modules in apache2, equivalent to the above Load Module directive:
    25 {{{
     27{{{#!sh
    2628a2enmod python
    2729}}}
     30
    2831On Fedora use, using yum:
    29 {{{
     32{{{#!sh
    3033yum install mod_python
    3134}}}
     35
    3236You can test your mod_python installation by adding the following to your httpd.conf. You should remove this when you are done testing for security reasons. Note: mod_python.testhandler is only available in mod_python 3.2+.
    33 {{{
    34 #!xml
     37{{{#!apache
    3538<Location /mpinfo>
    3639   SetHandler mod_python
    … …  
    4346
    4447A simple setup of Trac on mod_python looks like this:
    45 {{{
    46 #!xml
     48{{{#!apache
    4749<Location /projects/myproject>
    4850   SetHandler mod_python
    … …  
    5961
    6062The options available are:
    61 {{{
    62     # For a single project
    63     PythonOption TracEnv /var/trac/myproject
    64 
    65     # For multiple projects
    66     PythonOption TracEnvParentDir /var/trac/myprojects
    67 
    68     # For the index of multiple projects
    69     PythonOption TracEnvIndexTemplate /srv/www/htdocs/trac/project_list_template.html
    70 
    71     # A space delimitted list, with a "," between key and value pairs.
    72     PythonOption TracTemplateVars key1,val1 key2,val2
    73 
    74     # Useful to get the date in the wanted order
    75     PythonOption TracLocale en_GB.UTF8
    76 
    77     # See description above       
    78     PythonOption TracUriRoot /projects/myproject
     63{{{#!apache
     64# For a single project
     65PythonOption TracEnv /var/trac/myproject
     66
     67# For multiple projects
     68PythonOption TracEnvParentDir /var/trac/myprojects
     69
     70# For the index of multiple projects
     71PythonOption TracEnvIndexTemplate /srv/www/htdocs/trac/project_list_template.html
     72
     73# A space delimitted list, with a "," between key and value pairs.
     74PythonOption TracTemplateVars key1,val1 key2,val2
     75
     76# Useful to get the date in the wanted order
     77PythonOption TracLocale en_GB.UTF8
     78
     79# See description above       
     80PythonOption TracUriRoot /projects/myproject
    7981}}}
    8082
    8183=== Python Egg Cache
    8284
    83 Compressed python eggs like Genshi are normally extracted into a directory named `.python-eggs` in the users home directory. Since apache's home usually is not writable, an alternate egg cache directory can be specified like this:
    84 {{{
     85Compressed Python eggs like Genshi are normally extracted into a directory named `.python-eggs` in the users home directory. Since Apache's home usually is not writeable, an alternate egg cache directory can be specified like this:
     86{{{#!apache
    8587PythonOption PYTHON_EGG_CACHE /var/trac/myprojects/egg-cache
    8688}}}
    8789
    88 or you can uncompress the Genshi egg to resolve problems extracting from it.
     90Or you can uncompress the Genshi egg to resolve problems extracting from it.
    8991
    9092=== Configuring Authentication
    … …  
    9698=== Setting the Python Egg Cache
    9799
    98 If the Egg Cache isn't writeable by your Web server, you'll either have to change the permissions, or point Python to a location where Apache can write. This can manifest itself as a ''500 internal server error'' and/or a complaint in the syslog.
    99 
    100 {{{
    101 #!xml
     100If the Egg Cache isn't writeable by your Web server, you'll either have to change the permissions, or point Python to a location where Apache can write. This can manifest itself as a `500 internal server error` and/or a complaint in the syslog.
     101
     102{{{#!apache
    102103<Location /projects/myproject>
    103104  ...
    … …  
    109110=== Setting the !PythonPath
    110111
    111 If the Trac installation isn't installed in your Python path, you'll have to tell Apache where to find the Trac mod_python handler  using the `PythonPath` directive:
    112 {{{
    113 #!xml
     112If the Trac installation isn't installed in your Python path, you will have to tell Apache where to find the Trac mod_python handler  using the `PythonPath` directive:
     113{{{#!apache
    114114<Location /projects/myproject>
    115115  ...
    … …  
    124124
    125125The Trac mod_python handler supports a configuration option similar to Subversion's `SvnParentPath`, called `TracEnvParentDir`:
    126 {{{
    127 #!xml
     126{{{#!apache
    128127<Location /projects>
    129128  SetHandler mod_python
    … …  
    138137
    139138If you don't want to have the subdirectory listing as your projects home page you can use a
    140 {{{
    141 #!xml
     139{{{#!apache
    142140<LocationMatch "/.+/">
    143141}}}
    … …  
    146144
    147145You can also use the same authentication realm for all of the projects using a `<LocationMatch>` directive:
    148 {{{
    149 #!xml
     146{{{#!apache
    150147<LocationMatch "/projects/[^/]+/login">
    151148  AuthType Basic
    … …  
    158155=== Virtual Host Configuration
    159156
    160 Below is the sample configuration required to set up your trac as a virtual server, ie when you access it at the URLs like
    161 !http://trac.mycompany.com:
    162 
    163 {{{
    164 #!xml
    165 <VirtualHost * >
     157Below is the sample configuration required to set up your Trac as a virtual server, ie when you access it at the URLs like
     158`http://trac.mycompany.com`:
     159
     160{{{#!apache
     161<VirtualHost *>
    166162    DocumentRoot /var/www/myproject
    167163    ServerName trac.mycompany.com
    … …  
    183179
    184180This does not seem to work in all cases. What you can do if it does not:
    185  * Try using `<LocationMatch>` instead of `<Location>`
    186  * <Location /> may, in your server setup, refer to the complete host instead of simple the root of the server. This means that everything (including the login directory referenced below) will be sent to python and authentication does not work (i.e. you get the infamous Authentication information missing error). If this applies to you, try using a sub-directory for trac instead of the root, ie /web/ and /web/login instead of / and /login.
     181 * Try using `<LocationMatch>` instead of `<Location>`.
     182 * `<Location />` may, in your server setup, refer to the complete host instead of simple the root of the server. This means that everything (including the login directory referenced below) will be sent to Python and authentication does not work, ie you get the infamous Authentication information missing error. If this is the case, try using a sub-directory for Trac instead of the root, ie /web/ and /web/login instead of / and /login.
    187183 * Depending on apache's `NameVirtualHost` configuration, you may need to use `<VirtualHost *:80>` instead of `<VirtualHost *>`.
    188184
    189 For a virtual host that supports multiple projects replace "`TracEnv`" /var/trac/myproject with "`TracEnvParentDir`" /var/trac/
    190 
    191 Note: !DocumentRoot should not point to your Trac project env. As Asmodai wrote on #trac: "suppose there's a webserver bug that allows disclosure of !DocumentRoot they could then leech the entire Trac environment".
     185For a virtual host that supports multiple projects replace `TracEnv /var/trac/myproject` with `TracEnvParentDir /var/trac`.
     186
     187'''Note''': !DocumentRoot should not point to your Trac project env. As Asmodai wrote on #trac: "suppose there's a webserver bug that allows disclosure of !DocumentRoot they could then leech the entire Trac environment".
    192188
    193189== Troubleshooting
    194190
    195 In general, if you get server error pages, you can either check the Apache error log, or enable the `PythonDebug` option:
    196 {{{
    197 #!xml
     191If you get server error pages, you can either check the Apache error log, or enable the `PythonDebug` option:
     192{{{#!apache
    198193<Location /projects/myproject>
    199194  ...
    … …  
    208203If you've used `<Location />` directive, it will override any other directives, as well as `<Location /login>`.
    209204The workaround is to use negation expression as follows (for multi project setups):
    210 {{{
    211 #!xml
     205{{{#!apache
    212206#this one for other pages
    213207<Location ~ "/*(?!login)">
    … …  
    216210   PythonOption TracEnvParentDir /projects
    217211   PythonOption TracUriRoot /
    218 
    219 </Location>
     212</Location>
     213
    220214#this one for login page
    221215<Location ~ "/[^/]+/login">
    … …  
    255249=== Problem with zipped egg
    256250
    257 It's possible that your version of mod_python will not import modules from zipped eggs. If you encounter an `ImportError: No module named trac` in your Apache logs but you think everything is where it should be, this might be your problem. Look in your site-packages directory; if the Trac module appears as a ''file'' rather than a ''directory'', then this might be your problem. To rectify, try installing Trac using the `--always-unzip` option, like this:
    258 
    259 {{{
     251It's possible that your version of mod_python will not import modules from zipped eggs. If you encounter an `ImportError: No module named trac` in your Apache logs but you think everything is where it should be, this might be your problem. Look in your site-packages directory; if the Trac module appears as a ''file'' rather than a ''directory'', then this might be your problem. To rectify this, try installing Trac using the `--always-unzip` option:
     252
     253{{{#!sh
    260254easy_install --always-unzip Trac-0.12b1.zip
    261255}}}
    … …  
    268262
    269263This also works out-of-box, with following trivial config:
    270 {{{#!xml
     264{{{#!apache
    271265SetHandler mod_python
    272266PythonInterpreter main_interpreter
    … …  
    281275}}}
    282276
    283 The `TracUriRoot` is obviously the path you need to enter to the browser to get to Trac, eg domain.tld/projects/trac.
     277The `TracUriRoot` is obviously the path you need to enter to the browser to get to Trac, eg `domain.tld/projects/trac`.
    284278
    285279=== Additional .htaccess help
    286280
    287 If you are using the .htaccess method you may have additional problems if your trac directory is inheriting .htaccess directives from another. This may also help to add to your .htaccess file:
    288 
    289 {{{
     281If you are using the .htaccess method you may have additional problems if your Trac directory is inheriting .htaccess directives from another. This may also help to add to your .htaccess file:
     282
     283{{{#!apache
    290284<IfModule mod_rewrite.c>
    291285  RewriteEngine Off
    … …  
    296290==== Win32 Issues
    297291
    298 If you run trac with mod_python < 3.2 on Windows, uploading attachments will '''not''' work. This problem is resolved in mod_python 3.1.4 or later, so please upgrade mod_python to fix this.
     292If you run Trac with mod_python < 3.2 on Windows, uploading attachments will '''not''' work. This problem is resolved in mod_python 3.1.4 or later, so please upgrade mod_python to fix this.
    299293
    300294==== OS X issues
    301295
    302 When using mod_python on OS X you will not be able to restart Apache using `apachectl restart`. This is apparently fixed in mod_python 3.2, so please upgrade.
     296When using mod_python on OS X you will not be able to restart Apache using `apachectl restart`. This is apparently fixed in mod_python 3.2, so please upgrade mod_python to fix this.
    303297
    304298==== SELinux issues
    305299
    306 If Trac reports something like: ''Cannot get shared lock on db.lock''
    307 The security context on the repository may need to be set:
    308 
    309 {{{
     300If Trac reports something like: `Cannot get shared lock on db.lock`, then the security context on the repository may need to be set:
     301
     302{{{#!sh
    310303chcon -R -h -t httpd_sys_content_t PATH_TO_REPOSITORY
    311304}}}
    … …  
    315308==== FreeBSD issues
    316309
    317 The FreeBSD ports have both the new and old versions of mod_python and SQLite, but earlier versions of pysqlite and mod_python won't integrate as the former requires threaded support in Python, and the latter requires a threadless install.
    318 
    319 If you compiled and installed apache2, threads are not automatically supported on FreeBSD. You could force thread support when running `./configure` for Apache, using `--enable-threads`, but this isn´t recommended.
     310The FreeBSD ports have both the new and old versions of mod_python and SQLite, but earlier versions of pysqlite and mod_python won't integrate:
     311 * pysqlite requires threaded support in Python
     312 * mod_python requires a threadless install.
     313
     314Apache2 does not automatically support threads on FreeBSD. You could force thread support when running `./configure` for Apache, using `--enable-threads`, but this isn´t recommended.
    320315The best option [http://modpython.org/pipermail/mod_python/2006-September/021983.html seems to be] adding to /usr/local/apache2/bin/ennvars the line:
    321316
    322 {{{
     317{{{#!sh
    323318export LD_PRELOAD=/usr/lib/libc_r.so
    324319}}}
    … …  
    326321==== Fedora 7 Issues
    327322
    328 Make sure you install the 'python-sqlite2' package as it seems to be required for TracModPython but not for tracd.
     323Make sure you install the 'python-sqlite2' package as it seems to be required for TracModPython, but not for tracd.
    329324
    330325=== Subversion issues
    331326
    332 If you get the following Trac error `Unsupported version control system "svn"` only under mod_python, though it works well on the command-line and even with TracStandalone, chances are that you forgot to add the path to the Python bindings with the [TracModPython#ConfiguringPythonPath PythonPath] directive. The better way is to add a link to the bindings in the Python `site-packages` directory, or create a `.pth` file in that directory.
    333 
    334 If this is not the case, it's possible that you're using Subversion libraries that are binary incompatible with the Apache ones and an incompatibility of the `apr` libraries is usually the cause. In that case, you also won't be able to use the svn modules for Apache (`mod_dav_svn`).
     327If you get the following Trac error `Unsupported version control system "svn"` only under mod_python, though it works well on the command-line and even with TracStandalone, chances are that you forgot to add the path to the Python bindings with the [TracModPython#ConfiguringPythonPath PythonPath] directive. A better way is to add a link to the bindings in the Python `site-packages` directory, or create a `.pth` file in that directory.
     328
     329If this is not the case, it's possible that you are using Subversion libraries that are binary incompatible with the Apache ones and an incompatibility of the `apr` libraries is usually the cause. In that case, you also won't be able to use the svn modules for Apache (`mod_dav_svn`).
    335330
    336331You also need a recent version of `mod_python` in order to avoid a runtime error ({{{argument number 2: a 'apr_pool_t *' is expected}}}) due to the default usage of multiple sub-interpreters. Version 3.2.8 ''should'' work, though it's probably better to use the workaround described in [trac:#3371 #3371], in order to force the use of the main interpreter:
    337 {{{
     332{{{#!apache
    338333PythonInterpreter main_interpreter
    339334}}}
    340335
    341 This is anyway the recommended workaround for other well-known issues seen when using the Python bindings for Subversion within mod_python ([trac:#2611 #2611], [trac:#3455 #3455]). See in particular Graham Dumpleton's comment in [trac:comment:9:ticket:3455 #3455] explaining the issue.
     336This is also the recommended workaround for other issues seen when using the Python bindings for Subversion within mod_python ([trac:#2611 #2611], [trac:#3455 #3455]). See in particular Graham Dumpleton's comment in [trac:comment:9:ticket:3455 #3455] explaining the issue.
    342337
    343338=== Page layout issues
    344339
    345 If the formatting of the Trac pages look weird, chances are that the style sheets governing the page layout are not handled properly by the web server. Try adding the following lines to your apache configuration:
    346 {{{
    347 #!xml
     340If the formatting of the Trac pages look weird, chances are that the style sheets governing the page layout are not handled properly by the web server. Try adding the following lines to your Apache configuration:
     341{{{#!apache
    348342Alias /myproject/css "/usr/share/trac/htdocs/css"
    349343<Location /myproject/css>
    … …  
    352346}}}
    353347
    354 Note: For the above configuration to have any effect it must be put after the configuration of your project root location, i.e. {{{<Location /myproject />}}}.
     348'''Note''': For the above configuration to have any effect it must be put after the configuration of your project root location, ie {{{<Location /myproject />}}}.
    355349
    356350Also, setting `PythonOptimize On` seems to mess up the page headers and footers, in addition to hiding the documentation for macros and plugins (see #Trac8956). Considering how little effect the option has, leave it `Off`.
    … …  
    358352=== HTTPS issues
    359353
    360 If you want to run Trac fully under https you might find that it tries to redirect to plain http. In this case just add the following line to your apache configuration:
    361 {{{
    362 #!xml
    363 <VirtualHost * >
     354If you want to run Trac fully under https you might find that it tries to redirect to plain http. In this case just add the following line to your Apache configuration:
     355{{{#!apache
     356<VirtualHost *>
    364357    DocumentRoot /var/www/myproject
    365358    ServerName trac.mycompany.com
    … …  
    373366You may encounter segfaults (reported on Debian etch) if php5-mhash module is installed. Try to remove it to see if this solves the problem. See [http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=411487 Debian bug report].
    374367
    375 Some people also have troubles when using php5 compiled with its own 3rd party libraries instead of system libraries. Check [http://www.djangoproject.com/documentation/modpython/#if-you-get-a-segmentation-fault Django segmentation fault].
     368Some people also have troubles when using PHP5 compiled with its own third party libraries instead of system libraries. Check [http://www.djangoproject.com/documentation/modpython/#if-you-get-a-segmentation-fault Django segmentation fault].
    376369
    377370----