Changes between Version 2 and Version 3 of TracModPython


Ignore:
Timestamp:
22 Apr 2015 15:34:51 (5 years ago)
Author:
trac
Comment:

--

Legend:

Unmodified
Added
Removed
Modified
  • TracModPython

    v2 v3  
    1 = Trac and mod_python =
     1= Trac and mod_python
    22[[TracGuideToc]]
    33
     4Mod_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.
    45Trac supports [http://www.modpython.org/ mod_python], which speeds up Trac's response times considerably, especially compared to [TracCgi CGI], and permits use of many Apache features not possible with [wiki:TracStandalone tracd]/mod_proxy.
    56
    6 These instructions are for Apache 2; if you are still using Apache 1.3, you may have some luck with [trac:wiki:TracModPython2.7 TracModPython2.7].
    7 
    8 == Simple configuration ==
     7These instructions are for Apache 2. If you are using Apache 1.3, you may have some luck with [trac:wiki:TracModPython2.7 TracModPython2.7], but that is a deprecated setup.
     8
     9[[PageOutline(2-3,Overview,inline)]]
     10
     11== Simple configuration: single project == #Simpleconfiguration
    912
    1013If you just installed mod_python, you may have to add a line to load the module in the Apache configuration:
     
    1518''Note: The exact path to the module depends on how the HTTPD installation is laid out.''
    1619
    17 On Debian using apt-get
     20On Debian using apt-get:
    1821{{{
    1922apt-get install libapache2-mod-python libapache2-mod-python-doc
    2023}}}
    21 (Still on Debian) after you have installed mod_python, you must enable the modules in apache2 (equivalent of the above Load Module directive):
    22 {{{
    23 a2enmod mod_python
     24Still on Debian, after you have installed mod_python, you must enable the modules in apache2, equivalent to the above Load Module directive:
     25{{{
     26a2enmod python
    2427}}}
    2528On Fedora use, using yum:
     
    2730yum install mod_python
    2831}}}
    29 You 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+.
     32You 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+.
    3033{{{
    3134#!xml
     
    3437   PythonInterpreter main_interpreter
    3538   PythonHandler mod_python.testhandler
     39   Order allow,deny
     40   Allow from all
    3641</Location>
    3742}}}
     
    4651   PythonOption TracEnv /var/trac/myproject
    4752   PythonOption TracUriRoot /projects/myproject
    48 </Location>
    49 }}}
    50 
    51 The option '''`TracUriRoot`''' may or may not be necessary in your setup. Try your configuration without it; if the URLs produced by Trac look wrong, if Trac does not seem to recognize URLs correctly, or you get an odd "No handler matched request to..." error, add the '''`TracUriRoot`''' option.  You will notice that the `Location` and '''`TracUriRoot`''' have the same path.
    52 
    53 The options available are
     53   Order allow,deny
     54   Allow from all
     55</Location>
     56}}}
     57
     58The option '''`TracUriRoot`''' may or may not be necessary in your setup. Try your configuration without it; if the URLs produced by Trac look wrong, if Trac does not seem to recognize URLs correctly, or you get an odd "No handler matched request to..." error, add the '''`TracUriRoot`''' option. You will notice that the `Location` and '''`TracUriRoot`''' have the same path.
     59
     60The options available are:
    5461{{{
    5562    # For a single project
    5663    PythonOption TracEnv /var/trac/myproject
     64
    5765    # For multiple projects
    5866    PythonOption TracEnvParentDir /var/trac/myprojects
     67
    5968    # For the index of multiple projects
    6069    PythonOption TracEnvIndexTemplate /srv/www/htdocs/trac/project_list_template.html
     70
    6171    # A space delimitted list, with a "," between key and value pairs.
    6272    PythonOption TracTemplateVars key1,val1 key2,val2
     73
    6374    # Useful to get the date in the wanted order
    6475    PythonOption TracLocale en_GB.UTF8
     76
    6577    # See description above       
    6678    PythonOption TracUriRoot /projects/myproject
    6779}}}
    6880
    69 === Python Egg Cache ===
    70 
    71 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:
     81=== Python Egg Cache
     82
     83Compressed 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:
    7284{{{
    7385PythonOption PYTHON_EGG_CACHE /var/trac/myprojects/egg-cache
     
    7587
    7688or you can uncompress the Genshi egg to resolve problems extracting from it.
    77 === Configuring Authentication ===
    78 
    79 Creating password files and configuring authentication works similar to the process for [wiki:TracCgi#AddingAuthentication CGI]:
    80 {{{
    81 #!xml
    82 <Location /projects/myproject/login>
    83   AuthType Basic
    84   AuthName "myproject"
    85   AuthUserFile /var/trac/myproject/.htpasswd
    86   Require valid-user
    87 </Location>
    88 }}}
    89 
    90 Configuration for mod_ldap authentication in Apache is a bit tricky (httpd 2.2.x and OpenLDAP: slapd 2.3.19)
    91 
    92 1. You need to load the following modules in Apache httpd.conf
    93 {{{
    94 LoadModule ldap_module modules/mod_ldap.so
    95 LoadModule authnz_ldap_module modules/mod_authnz_ldap.so
    96 }}}
    97 
    98 2. Your httpd.conf also needs to look something like:
    99 
    100 {{{
    101 #!xml
    102 <Location /trac/>
    103   SetHandler mod_python
    104   PythonInterpreter main_interpreter
    105   PythonHandler trac.web.modpython_frontend
    106   PythonOption TracEnv /home/trac/
    107   PythonOption TracUriRoot /trac/
    108   Order deny,allow
    109   Deny from all
    110   Allow from 192.168.11.0/24
    111   AuthType Basic
    112   AuthName "Trac"
    113   AuthBasicProvider "ldap"
    114   AuthLDAPURL "ldap://127.0.0.1/dc=example,dc=co,dc=ke?uid?sub?(objectClass=inetOrgPerson)"
    115   authzldapauthoritative Off
    116   require valid-user
    117 </Location>
    118 }}}
    119 
    120 Or the LDAP interface to a Microsoft Active Directory:
    121 
    122 {{{
    123 #!xml
    124 <Location /trac/>
    125   SetHandler mod_python
    126   PythonInterpreter main_interpreter
    127   PythonHandler trac.web.modpython_frontend
    128   PythonOption TracEnv /home/trac/
    129   PythonOption TracUriRoot /trac/
    130   Order deny,allow
    131   Deny from all
    132   Allow from 192.168.11.0/24
    133   AuthType Basic
    134   AuthName "Trac"
    135   AuthBasicProvider "ldap"
    136   AuthLDAPURL "ldap://adserver.company.com:3268/DC=company,DC=com?sAMAccountName?sub?(objectClass=user)"
    137   AuthLDAPBindDN       ldap-auth-user@company.com
    138   AuthLDAPBindPassword "the_password"
    139   authzldapauthoritative Off
    140   # require valid-user
    141   require ldap-group CN=Trac Users,CN=Users,DC=company,DC=com
    142 </Location>
    143 }}}
    144 
    145 Note 1: This is the case where the LDAP search will get around the multiple OUs, conecting to Global Catalog Server portion of AD (Notice the port is 3268, not the normal LDAP 389). The GCS is basically a "flattened" tree which allows searching for a user without knowing to which OU they belong.
    146 
    147 Note 2: Active Directory requires an authenticating user/password to access records (AuthLDAPBindDN and AuthLDAPBindPassword).
    148 
    149 Note 3: The directive "require ldap-group ..."  specifies an AD group whose members are allowed access.
    150 
    151 
    152 === Setting the Python Egg Cache ===
     89
     90=== Configuring Authentication
     91
     92See corresponding section in the [wiki:TracModWSGI#ConfiguringAuthentication] page.
     93
     94== Advanced Configuration
     95
     96=== Setting the Python Egg Cache
    15397
    15498If 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.
     
    163107}}}
    164108
    165 
    166 === Setting the !PythonPath ===
     109=== Setting the !PythonPath
    167110
    168111If 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:
     
    178121Be careful about using the !PythonPath directive, and ''not'' `SetEnv PYTHONPATH`, as the latter won't work.
    179122
    180 == Setting up multiple projects ==
     123=== Setting up multiple projects
    181124
    182125The Trac mod_python handler supports a configuration option similar to Subversion's `SvnParentPath`, called `TracEnvParentDir`:
     
    213156}}}
    214157
    215 == Virtual Host Configuration ==
    216 
    217 Below is the sample configuration required to set up your trac as a virtual server (i.e. when you access it at the URLs like
    218 !http://trac.mycompany.com):
     158=== Virtual Host Configuration
     159
     160Below 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:
    219162
    220163{{{
     
    241184This does not seem to work in all cases. What you can do if it does not:
    242185 * Try using `<LocationMatch>` instead of `<Location>`
    243  * <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 (i.e. /web/ and /web/login instead of / and /login).
     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.
    244187 * Depending on apache's `NameVirtualHost` configuration, you may need to use `<VirtualHost *:80>` instead of `<VirtualHost *>`.
    245188
     
    248191Note: !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".
    249192
    250 == Troubleshooting ==
     193== Troubleshooting
    251194
    252195In general, if you get server error pages, you can either check the Apache error log, or enable the `PythonDebug` option:
     
    261204For multiple projects, try restarting the server as well.
    262205
     206=== Login Not Working
     207
     208If you've used `<Location />` directive, it will override any other directives, as well as `<Location /login>`.
     209The workaround is to use negation expression as follows (for multi project setups):
     210{{{
     211#!xml
     212#this one for other pages
     213<Location ~ "/*(?!login)">
     214   SetHandler mod_python
     215   PythonHandler trac.web.modpython_frontend
     216   PythonOption TracEnvParentDir /projects
     217   PythonOption TracUriRoot /
     218
     219</Location>
     220#this one for login page
     221<Location ~ "/[^/]+/login">
     222   SetHandler mod_python
     223   PythonHandler trac.web.modpython_frontend
     224   PythonOption TracEnvParentDir /projects
     225   PythonOption TracUriRoot /
     226
     227   #remove these if you don't want to force SSL
     228   RewriteEngine On
     229   RewriteCond %{HTTPS} off
     230   RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}
     231
     232   AuthType Basic
     233   AuthName "Trac"
     234   AuthUserFile /projects/.htpasswd
     235   Require valid-user
     236</Location>
     237}}}
     238
    263239=== Expat-related segmentation faults === #expat
    264240
    265241This problem will most certainly hit you on Unix when using Python 2.4.
    266 In Python 2.4, some version of Expat (an XML parser library written in C) is used,
    267 and if Apache is using another version, this results in segmentation faults.
    268 As Trac 0.11 is using Genshi, which will indirectly use Expat, that problem
    269 can now hit you even if everything was working fine before with Trac 0.10.
    270 
    271 See Graham Dumpleton's detailed [http://www.dscpl.com.au/wiki/ModPython/Articles/ExpatCausingApacheCrash explanation and workarounds] for the issue.
    272 
    273 === Form submission problems ===
     242In Python 2.4, some version of [http://expat.sourceforge.net/ Expat] (an XML parser library written in C) is used and if Apache is using another version, this results in segmentation faults.
     243As Trac 0.11 is using Genshi, which will indirectly use Expat, that problem can now hit you even if everything was working fine before with Trac 0.10. This problem has not been reported for Python 2.5+, so best to upgrade.
     244
     245=== Form submission problems
    274246
    275247If you're experiencing problems submitting some of the forms in Trac (a common problem is that you get redirected to the start page after submission), check whether your {{{DocumentRoot}}} contains a folder or file with the same path that you mapped the mod_python handler to. For some reason, mod_python gets confused when it is mapped to a location that also matches a static resource.
    276248
    277 === Problem with virtual host configuration ===
    278 
    279 If the <Location /> directive is used, setting the `DocumentRoot` may result in a ''403 (Forbidden)'' error. Either remove the `DocumentRoot` directive, or make sure that accessing the directory it points is allowed (in a corresponding `<Directory>` block).
    280 
    281 Using <Location /> together with `SetHandler` resulted in having everything handled by mod_python, which leads to not being able download any CSS or images/icons. I used <Location /trac> `SetHandler None` </Location> to circumvent the problem, though I do not know if this is the most elegant solution.
    282 
    283 === Using .htaccess ===
     249=== Problem with virtual host configuration
     250
     251If the <Location /> directive is used, setting the `DocumentRoot` may result in a ''403 (Forbidden)'' error. Either remove the `DocumentRoot` directive, or make sure that accessing the directory it points is allowed, in a corresponding `<Directory>` block.
     252
     253Using <Location /> together with `SetHandler` resulted in having everything handled by mod_python, which leads to not being able to download any CSS or images/icons. Use <Location /trac> `SetHandler None` </Location> to circumvent the problem, though this may not be the most elegant solution.
     254
     255=== Problem with zipped egg
     256
     257It'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{{{
     260easy_install --always-unzip Trac-0.12b1.zip
     261}}}
     262
     263=== Using .htaccess
    284264
    285265Although it may seem trivial to rewrite the above configuration as a directory in your document root with a `.htaccess` file, this does not work. Apache will append a "/" to any Trac URLs, which interferes with its correct operation.
    286266
    287 It may be possible to work around this with mod_rewrite, but I failed to get this working. In all, it is more hassle than it is worth. Stick to the provided instructions. :)
    288 
    289 A success story: For me it worked out-of-box, with following trivial config:
    290 {{{
     267It may be possible to work around this with mod_rewrite, but I failed to get this working. In all, it is more hassle than it is worth.
     268
     269This also works out-of-box, with following trivial config:
     270{{{#!xml
    291271SetHandler mod_python
    292272PythonInterpreter main_interpreter
     
    301281}}}
    302282
    303 The `TracUriRoot` is obviously the path you need to enter to the browser to get to the trac (e.g. domain.tld/projects/trac)
    304 
    305 === Additional .htaccess help ===
    306 
    307 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:
     283The `TracUriRoot` is obviously the path you need to enter to the browser to get to Trac, eg domain.tld/projects/trac.
     284
     285=== Additional .htaccess help
     286
     287If 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:
    308288
    309289{{{
     
    313293}}}
    314294
    315 
    316 === Win32 Issues ===
     295=== Platform specific issues
     296==== Win32 Issues
     297
    317298If 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.
    318299
    319 
    320 === OS X issues ===
    321 
    322 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, but there's also a patch available for earlier versions [http://www.dscpl.com.au/projects/vampire/patches.html here].
    323 
    324 === SELinux issues ===
     300==== OS X issues
     301
     302When 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.
     303
     304==== SELinux issues
    325305
    326306If Trac reports something like: ''Cannot get shared lock on db.lock''
     
    331311}}}
    332312
    333 See also [http://subversion.tigris.org/faq.html#reposperms]
    334 
    335 === FreeBSD issues ===
    336 Pay attention to the version of the installed mod_python and sqlite packages. Ports have both the new and old ones, 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.
    337 
    338 If you compiled and installed apache2, apache wouldn´t support threads (cause it doesn´t work very well on FreeBSD). You could force thread support when running ./configure for apache, using --enable-threads, but this isn´t recommendable.
    339 The best option [http://modpython.org/pipermail/mod_python/2006-September/021983.html seems to be] adding to /usr/local/apache2/bin/ennvars the line
     313See also [http://subversion.apache.org/faq.html#reposperms How do I set repository permissions correctly?]
     314
     315==== FreeBSD issues
     316
     317The 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
     319If 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.
     320The best option [http://modpython.org/pipermail/mod_python/2006-September/021983.html seems to be] adding to /usr/local/apache2/bin/ennvars the line:
    340321
    341322{{{
     
    343324}}}
    344325
    345 === Subversion issues ===
    346 
    347 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.)
    348 
    349 If this is not the case, it's possible that you're using Subversion libraries that are binary incompatible with the apache ones (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`).
    350 
    351 You 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. 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:
     326==== Fedora 7 Issues
     327
     328Make sure you install the 'python-sqlite2' package as it seems to be required for TracModPython but not for tracd.
     329
     330=== Subversion issues
     331
     332If 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
     334If 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`).
     335
     336You 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:
    352337{{{
    353338PythonInterpreter main_interpreter
    354339}}}
     340
    355341This 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.
    356342
    357 === Page layout issues ===
    358 
    359 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:
     343=== Page layout issues
     344
     345If 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:
    360346{{{
    361347#!xml
     
    368354Note: For the above configuration to have any effect it must be put after the configuration of your project root location, i.e. {{{<Location /myproject />}}}.
    369355
    370 === HTTPS issues ===
     356Also, 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`.
     357
     358=== HTTPS issues
    371359
    372360If 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:
     
    381369}}}
    382370
    383 === Fedora 7 Issues ===
    384 Make sure you install the 'python-sqlite2' package as it seems to be required for TracModPython but not for tracd
    385 
    386 
    387 === Segmentation fault with php5-mhash or other php5 modules ===
    388 You 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 debian bug report [http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=411487]
    389 
    390 Some people also have troubles when using php5 compiled with its own 3rd party libraries instead of system libraries. Check here [http://www.djangoproject.com/documentation/modpython/#if-you-get-a-segmentation-fault]
     371=== Segmentation fault with php5-mhash or other php5 modules
     372
     373You 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].
     374
     375Some 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].
    391376
    392377----
    393 See also:  TracGuide, TracInstall, [wiki:TracModWSGI ModWSGI], [wiki:TracFastCgi FastCGI], [wiki:TracModPython ModPython], [trac:TracNginxRecipe TracNginxRecipe]
     378See also: TracGuide, TracInstall, [wiki:TracModWSGI ModWSGI], [wiki:TracFastCgi FastCGI], [trac:TracNginxRecipe]