Changes between Version 5 and Version 6 of TracModWSGI


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Timestamp:
03/24/15 23:15:03 (2 years ago)
Author:
trac
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  • TracModWSGI

    v5 v6  
    11= Trac and mod_wsgi =
    22
    3 [http://code.google.com/p/modwsgi/ mod_wsgi] is an Apache module for running WSGI-compatible Python applications directly on top of the Apache webserver. The mod_wsgi adapter is written completely in C and provides very good performance.
     3
     4[http://code.google.com/p/modwsgi/ mod_wsgi] is an Apache module for running WSGI-compatible Python applications directly on top of the Apache webserver. The mod_wsgi adapter is written completely in C and provides very good performances.
    45
    56[[PageOutline(2-3,Overview,inline)]]
     
    78== The `trac.wsgi` script
    89
    9 Trac can be run on top of mod_wsgi with the help of the following application script, which is just a Python file, though usually saved with a `.wsgi` extension.
     10Trac can be run on top of mod_wsgi with the help of the following application script, which is just a Python file, though usually saved with a `.wsgi` extension).
    1011
    1112=== A very basic script
     
    2223}}}
    2324
    24 The `TRAC_ENV` variable should naturally be the directory for your Trac environment, and the `PYTHON_EGG_CACHE` should be a directory where Python can temporarily extract Python eggs. If you have several Trac environments in a directory, you can also use `TRAC_ENV_PARENT_DIR` instead of `TRAC_ENV`.
    25 
    26 On Windows:
    27  - If run under the user's session, the Python Egg cache can be found in `%AppData%\Roaming`, for example:
    28 {{{#!python
    29 os.environ['PYTHON_EGG_CACHE'] = r'C:\Users\Administrator\AppData\Roaming\Python-Eggs'
    30 }}}
    31  - If run under a Window service, you should create a directory for Python Egg cache:
    32 {{{#!python
    33 os.environ['PYTHON_EGG_CACHE'] = r'C:\Trac-Python-Eggs'
    34 }}}
     25The `TRAC_ENV` variable should naturally be the directory for your Trac environment (if you have several Trac environments in a directory, you can also use `TRAC_ENV_PARENT_DIR` instead), while the `PYTHON_EGG_CACHE` should be a directory where Python can temporarily extract Python eggs.
    3526
    3627=== A more elaborate script
    3728
    38 If you are using multiple `.wsgi` files (for example one per Trac environment) you must ''not'' use `os.environ['TRAC_ENV']` to set the path to the Trac environment. Using this method may lead to Trac delivering the content of another Trac environment, as the variable may be filled with the path of a previously viewed Trac environment.
     29If you're using multiple `.wsgi` files (for example one per Trac environment) you must ''not'' use `os.environ['TRAC_ENV']` to set the path to the Trac environment. Using this method may lead to Trac delivering the content of another Trac environment, as the variable may be filled with the path of a previously viewed Trac environment.
    3930
    4031To solve this problem, use the following `.wsgi` file instead:
     
    5243For clarity, you should give this file a `.wsgi` extension. You should probably put the file in its own directory, since you will expose it to Apache.
    5344
    54 If you have installed Trac and Python eggs in a path different from the standard one, you should add that path by adding the following code at the top of the wsgi script:
     45If you have installed Trac and eggs in a path different from the standard one you should add that path by adding the following code at the top of the wsgi script:
    5546
    5647{{{#!python
     
    6354=== Recommended `trac.wsgi` script
    6455
    65 A somewhat robust and generic version of this file can be created using the `trac-admin <env> deploy <dir>` command which automatically substitutes the required paths, see TracInstall#cgi-bin.
    66 
    67 If you are using Trac with multiple projects, you can specify their common parent directory using the `TRAC_ENV_PARENT_DIR` in the trac.wsgi in trac.wsgi: ''
    68 
    69 {{{#!python
    70   def application(environ, start_request):
    71       Add this to config when you have multiple projects                                             
    72       environ.setdefault('trac.env_parent_dir', '/usr/share/trac/projects') 
    73       ..
    74       ..
    75 }}}
     56A somewhat robust and generic version of this file can be created using the `trac-admin <env> deploy <dir>` command which automatically substitutes the required paths (see TracInstall#cgi-bin).
     57
    7658
    7759== Mapping requests to the script
    7860
    79 After preparing your .wsgi script, add the following to your Apache configuration file, typically `httpd.conf`:
     61After you've done preparing your .wsgi script, add the following to your Apache configuration file (`httpd.conf` for example).
    8062
    8163{{{
     
    9173Here, the script is in a subdirectory of the Trac environment.
    9274
    93 If you followed the directions [TracInstall#cgi-bin Generating the Trac cgi-bin directory], your Apache configuration file should look like following:
     75If you followed the directions [http://trac.edgewall.org/wiki/TracInstall#cgi-bin Generating the Trac cgi-bin directory], your Apache configuration file should look like following:
    9476
    9577{{{
     
    10385}}}
    10486
    105 In order to let Apache run the script, access to the directory in which the script resides is opened up to all of Apache. Additionally, the `WSGIApplicationGroup` directive ensures that Trac is always run in the first Python interpreter created by mod_wsgi. This is necessary because the Subversion Python bindings, which are used by Trac, don't always work in other sub-interpreters and may cause requests to hang or cause Apache to crash. After adding this configuration, restart Apache, and then it should work.
     87In order to let Apache run the script, access to the directory in which the script resides is opened up to all of Apache. Additionally, the `WSGIApplicationGroup` directive ensures that Trac is always run in the first Python interpreter created by mod_wsgi; this is necessary because the Subversion Python bindings, which are used by Trac, don't always work in other sub-interpreters and may cause requests to hang or cause Apache to crash as a result. After adding this configuration, restart Apache, and then it should work.
    10688
    10789To test the setup of Apache, mod_wsgi and Python itself (ie. without involving Trac and dependencies), this simple wsgi application can be used to make sure that requests gets served (use as only content in your `.wsgi` script):
     
    11597For more information about using the mod_wsgi specific directives, see the [http://code.google.com/p/modwsgi/wiki/ mod_wsgi's wiki] and more specifically the [http://code.google.com/p/modwsgi/wiki/IntegrationWithTrac IntegrationWithTrac] page.
    11698
     99
    117100== Configuring Authentication
    118101
    119 The following sections describe different methods for setting up authentication. See also [http://httpd.apache.org/docs/2.2/howto/auth.html Authentication, Authorization and Access Control] in the Apache guide.
     102We describe in the the following sections different methods for setting up authentication.
     103
     104See also [http://httpd.apache.org/docs/2.2/howto/auth.html Authentication, Authorization and Access Control] in the Apache guide.
    120105
    121106=== Using Basic Authentication ===
    122107
    123 The simplest way to enable authentication with Apache is to create a password file. Use the `htpasswd` program as follows:
     108The simplest way to enable authentication with Apache is to create a password file. Use the `htpasswd` program to create the password file:
    124109{{{
    125110$ htpasswd -c /somewhere/trac.htpasswd admin
     
    129114}}}
    130115
    131 After the first user, you don't need the "-c" option anymore:
     116After the first user, you dont need the "-c" option anymore:
    132117{{{
    133118$ htpasswd /somewhere/trac.htpasswd john
     
    141126After you've created the users, you can set their permissions using TracPermissions.
    142127
    143 Now, you need to enable authentication against the password file in the Apache configuration:
     128Now, you'll need to enable authentication against the password file in the Apache configuration:
    144129{{{
    145130<Location "/trac/login">
     
    151136}}}
    152137
    153 If you are hosting multiple projects, you can use the same password file for all of them:
     138If you're hosting multiple projects you can use the same password file for all of them:
    154139{{{
    155140<LocationMatch "/trac/[^/]+/login">
     
    167152For better security, it is recommended that you either enable SSL or at least use the “digest” authentication scheme instead of “Basic”.
    168153
    169 You have to create your `.htpasswd` file with the `htdigest` command instead of `htpasswd`, as follows:
     154You'll have to create your `.htpasswd` file with the `htdigest` command instead of `htpasswd`, as follows:
    170155{{{
    171156# htdigest -c /somewhere/trac.htpasswd trac admin
     
    187172For multiple environments, you can use the same `LocationMatch` as described with the previous method.
    188173
    189 '''Note: `Location` cannot be used inside .htaccess files, but must instead live within the main httpd.conf file. If you are on a shared server, you therefore will not be able to provide this level of granularity. '''
    190 
    191174Don't forget to activate the mod_auth_digest. For example, on a Debian 4.0r1 (etch) system:
    192175{{{
     
    194177}}}
    195178
     179
    196180See also the [http://httpd.apache.org/docs/2.2/mod/mod_auth_digest.html mod_auth_digest] documentation.
    197181
    198182=== Using LDAP Authentication
    199183
    200 Configuration for [http://httpd.apache.org/docs/2.2/mod/mod_ldap.html mod_ldap] authentication in Apache is more involved (httpd 2.2.x and OpenLDAP: slapd 2.3.19).
    201 
    202 1. You need to load the following modules in Apache httpd.conf:
     184Configuration for [http://httpd.apache.org/docs/2.2/mod/mod_ldap.html mod_ldap] authentication in Apache is a bit tricky (httpd 2.2.x and OpenLDAP: slapd 2.3.19)
     185
     1861. You need to load the following modules in Apache httpd.conf
    203187{{{
    204188LoadModule ldap_module modules/mod_ldap.so
     
    223207}}}
    224208
     209
    2252103. You can use the LDAP interface as a way to authenticate to a Microsoft Active Directory:
    226211
     212
    227213Use the following as your LDAP URL:
    228214{{{
     
    230216}}}
    231217
    232 You will also need to provide an account for Apache to use when checking credentials. As this password will be listed in plaintext in the config, you need to use an account specifically for this task:
     218You will also need to provide an account for Apache to use when checking
     219credentials. As this password will be listed in plaintext in the
     220config, you should be sure to use an account specifically for this task:
    233221{{{
    234222    AuthLDAPBindDN ldap-auth-user@example.com
     
    255243}}}
    256244
    257 Note 1: This is the case where the LDAP search will get around the multiple OUs, conecting to the Global Catalog Server portion of AD. Note 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.
    258 
    259 Note 2: You can also require the user be a member of a certain LDAP group, instead of just having a valid login:
     245Note 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.
     246
     247Note 2: You can also require the user be a member of a certain LDAP group, instead of
     248just having a valid login:
    260249{{{
    261250    Require ldap-group CN=Trac Users,CN=Users,DC=example,DC=com
     
    263252
    264253See also:
    265  - [http://httpd.apache.org/docs/2.2/mod/mod_authnz_ldap.html mod_authnz_ldap], documentation for mod_authnz_ldap.   
     254  - [http://httpd.apache.org/docs/2.2/mod/mod_authnz_ldap.html mod_authnz_ldap], documentation for mod_authnz_ldap
     255   
    266256 - [http://httpd.apache.org/docs/2.2/mod/mod_ldap.html mod_ldap], documentation for mod_ldap, which provides connection pooling and a shared cache.
    267257 - [http://trac-hacks.org/wiki/LdapPlugin TracHacks:LdapPlugin] for storing TracPermissions in LDAP.
     
    269259=== Using SSPI Authentication
    270260
    271 If you are using Apache on Windows, you can use mod_auth_sspi to provide single-sign-on. Download the module from the !SourceForge [http://sourceforge.net/projects/mod-auth-sspi/ mod-auth-sspi project] and then add the following to your !VirtualHost:
     261If you are using Apache on Windows, you can use mod_auth_sspi to provide
     262single-sign-on. Download the module from the !SourceForge [http://sourceforge.net/projects/mod-auth-sspi/ mod-auth-sspi project] and then add the
     263following to your !VirtualHost:
    272264{{{
    273265    <Location /trac/login>
     
    284276}}}
    285277
    286 Using the above, usernames in Trac will be of the form `DOMAIN\username`, so you may have to re-add permissions and such. If you do not want the domain to be part of the username, set `SSPIOmitDomain On` instead.
     278Using the above, usernames in Trac will be of the form `DOMAIN\username`, so
     279you may have to re-add permissions and such. If you do not want the domain to
     280be part of the username, set `SSPIOmitDomain On` instead.
    287281
    288282Some common problems with SSPI authentication: [trac:#1055], [trac:#1168] and [trac:#3338].
     
    314308</Location>
    315309}}}
    316 Note that '''authFile''' need not exist (unless you are using Account Manager older than 0.4). See the !HttpAuthStore link above for examples where multiple Trac projects are hosted on a server.
     310Note that '''authFile''' need not exist. See the !HttpAuthStore link above for examples where multiple Trac projects are hosted on a server.
    317311
    318312=== Example: Apache/mod_wsgi with Basic Authentication, Trac being at the root of a virtual host
    319313
    320 Per the mod_wsgi documentation linked to above, here is an example Apache configuration that:
    321  - serves the Trac instance from a virtualhost subdomain
    322  - uses Apache basic authentication for Trac authentication.
     314Per the mod_wsgi documentation linked to above, here is an example Apache configuration that a) serves the Trac instance from a virtualhost subdomain and b) uses Apache basic authentication for Trac authentication.
     315
    323316
    324317If you want your Trac to be served from e.g. !http://trac.my-proj.my-site.org, then from the folder e.g. `/home/trac-for-my-proj`, if you used the command `trac-admin the-env initenv` to create a folder `the-env`, and you used `trac-admin the-env deploy the-deploy` to create a folder `the-deploy`, then first:
     
    331324htpasswd htpasswd seconduser
    332325}}}
    333 Keep the file above your document root for security reasons.
    334 
    335 Create this file e.g. (ubuntu) `/etc/apache2/sites-enabled/trac.my-proj.my-site.org.conf` with the following content:
     326(keep the file above your document root for security reasons)
     327
     328Create this file e.g. (ubuntu) `/etc/apache2/sites-enabled/trac.my-proj.my-site.org.conf` with the following contents:
    336329
    337330{{{
     
    358351Note: for subdomains to work you would probably also need to alter `/etc/hosts` and add A-Records to your host's DNS.
    359352
     353
    360354== Troubleshooting
    361355
    362356=== Use a recent version
    363357
    364 Please use either version 1.6, 2.4 or later of `mod_wsgi`. Versions prior to 2.4 in the 2.X branch have problems with some Apache configurations that use WSGI file wrapper extension. This extension is used in Trac to serve up attachments and static media files such as style sheets. If you are affected by this problem, attachments will appear to be empty and formatting of HTML pages will appear not to work due to style sheet files not loading properly. Another frequent symptom is that binary attachment downloads are truncated. See mod_wsgi tickets [http://code.google.com/p/modwsgi/issues/detail?id=100 #100] and [http://code.google.com/p/modwsgi/issues/detail?id=132 #132].
     358Please use either version 1.6, 2.4 or later of `mod_wsgi`. Versions prior to 2.4 in the 2.X branch have problems with some Apache configurations that use WSGI file wrapper extension. This extension is used in Trac to serve up attachments and static media files such as style sheets. If you are affected by this problem attachments will appear to be empty and formatting of HTML pages will appear not to work due to style sheet files not loading properly. Another frequent symptom is that binary attachment downloads are truncated. See mod_wsgi tickets [http://code.google.com/p/modwsgi/issues/detail?id=100 #100] and [http://code.google.com/p/modwsgi/issues/detail?id=132 #132].
    365359
    366360''Note: using mod_wsgi 2.5 and Python 2.6.1 gave an Internal Server Error on my system (Apache 2.2.11 and Trac 0.11.2.1). Upgrading to Python 2.6.2 (as suggested [http://www.mail-archive.com/modwsgi@googlegroups.com/msg01917.html here]) solved this for me[[BR]]-- Graham Shanks''
    367361
    368 If you plan to use `mod_wsgi` in embedded mode on Windows or with the MPM worker on Linux, then you will need version 0.3.4 or greater. See [trac:#10675] for details.
     362If you plan to use `mod_wsgi` in embedded mode on Windows or with the MPM worker on Linux, then you'll even need version 0.3.4 or greater (see [trac:#10675] for details).
    369363
    370364=== Getting Trac to work nicely with SSPI and 'Require Group' ===
    371 
    372 If you have set Trac up on Apache, Win32 and configured SSPI, but added a 'Require group' option to your apache configuration, then the SSPIOmitDomain option is probably not working. If it is not working, your usernames in Trac probably look like 'DOMAIN\user' rather than 'user'.
    373 
    374 This WSGI script 'fixes' that:
     365If like me you've set Trac up on Apache, Win32 and configured SSPI, but added a 'Require group' option to your apache configuration, then the SSPIOmitDomain option is probably not working.  If its not working your usernames in trac are probably looking like 'DOMAIN\user' rather than 'user'.
     366
     367This WSGI script 'fixes' things, hope it helps:
    375368{{{#!python
    376369import os
     
    386379}}}
    387380
     381
    388382=== Trac with PostgreSQL ===
    389383
    390 When using the mod_wsgi adapter with multiple Trac instances and PostgreSQL (or MySQL?) as the database, the server ''may'' create a lot of open database connections and thus PostgreSQL processes.
    391 
    392 A somewhat brutal workaround is to disable connection pooling in Trac. This is done by setting `poolable = False` in `trac.db.postgres_backend` on the `PostgreSQLConnection` class.
    393 
    394 But it is not necessary to edit the source of Trac. The following lines in `trac.wsgi` will also work:
    395 
    396 {{{#!python
     384When using the mod_wsgi adapter with multiple Trac instances and PostgreSQL (or MySQL?) as a database back-end, the server ''may'' create a lot of open database connections and thus PostgreSQL processes.
     385
     386A somewhat brutal workaround is to disabled connection pooling in Trac. This is done by setting `poolable = False` in `trac.db.postgres_backend` on the `PostgreSQLConnection` class.
     387
     388But it's not necessary to edit the source of Trac, the following lines in `trac.wsgi` will also work:
     389
     390{{{
    397391import trac.db.postgres_backend
    398392trac.db.postgres_backend.PostgreSQLConnection.poolable = False
     
    401395or
    402396
    403 {{{#!python
     397{{{
    404398import trac.db.mysql_backend
    405399trac.db.mysql_backend.MySQLConnection.poolable = False
    406400}}}
    407401
    408 Now Trac drops the connection after serving a page and the connection count on the database will be kept low.
     402Now Trac drops the connection after serving a page and the connection count on the database will be kept minimal.
    409403
    410404//This is not a recommended approach though. See also the notes at the bottom of the [http://code.google.com/p/modwsgi/wiki/IntegrationWithTrac mod_wsgi's IntegrationWithTrac] wiki page.//
     
    414408For more troubleshooting tips, see also the [TracModPython#Troubleshooting mod_python troubleshooting] section, as most Apache-related issues are quite similar, plus discussion of potential [http://code.google.com/p/modwsgi/wiki/ApplicationIssues application issues] when using mod_wsgi. The wsgi page also has a [http://code.google.com/p/modwsgi/wiki/IntegrationWithTrac Integration With Trac] document.
    415409
     410
    416411----
    417 See also: TracGuide, TracInstall, [wiki:TracFastCgi FastCGI], [wiki:TracModPython ModPython], [trac:TracNginxRecipe TracNginxRecipe]
     412See also:  TracGuide, TracInstall, [wiki:TracFastCgi FastCGI], [wiki:TracModPython ModPython], [trac:TracNginxRecipe TracNginxRecipe]