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Changes between Version 7 and Version 8 of TracModWSGI


Ignore:
Timestamp:
Mar 25, 2015 10:37:29 AM (6 years ago)
Author:
trac
Comment:

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  • TracModWSGI

    v7 v8  
    1 = Trac and mod_wsgi =
    2 
    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 performance.
     1= Trac and mod_wsgi
     2
     3[https://github.com/GrahamDumpleton/mod_wsgi 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.
    54
    65[[PageOutline(2-3,Overview,inline)]]
     
    87== The `trac.wsgi` script
    98
    10 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).
     9Trac can be run on top of mod_wsgi with the help of an application script, which is just a Python file saved with a `.wsgi` extension.
     10
     11A 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. The script should be sufficient for most installations and users not wanting more information can proceed to [#Mappingrequeststothescript configuring Apache].
     12
     13If you are using Trac with multiple projects, you can specify their common parent directory using the `TRAC_ENV_PARENT_DIR` in trac.wsgi:
     14{{{#!python
     15def application(environ, start_request):
     16    # Add this to config when you have multiple projects                                             
     17    environ.setdefault('trac.env_parent_dir', '/usr/share/trac/projects') 
     18    ..
     19}}}
    1120
    1221=== A very basic script
     
    2332}}}
    2433
    25 The `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.
     34The `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`.
    2635
    2736On Windows:
     
    3039os.environ['PYTHON_EGG_CACHE'] = r'C:\Users\Administrator\AppData\Roaming\Python-Eggs'
    3140}}}
    32  - If run under a Window service, you should create a directory for Python Egg cache.
     41 - If run under a Window service, you should create a directory for Python Egg cache:
    3342{{{#!python
    3443os.environ['PYTHON_EGG_CACHE'] = r'C:\Trac-Python-Eggs'
     
    3746=== A more elaborate script
    3847
    39 If 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.
     48If 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.
    4049
    4150To solve this problem, use the following `.wsgi` file instead:
     
    5362For 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.
    5463
    55 If 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:
     64If 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:
    5665
    5766{{{#!python
     
    6271Change it according to the path you installed the Trac libs at.
    6372
    64 === Recommended `trac.wsgi` script
    65 
    66 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).
    67 
    68 
    6973== Mapping requests to the script
    7074
    71 After you've done preparing your .wsgi script, add the following to your Apache configuration file (`httpd.conf` for example).
    72 
    73 {{{
     75After preparing your .wsgi script, add the following to your Apache configuration file, typically `httpd.conf`:
     76
     77{{{#!apache
    7478WSGIScriptAlias /trac /usr/local/trac/mysite/apache/mysite.wsgi
    7579
     
    8589If you followed the directions [TracInstall#cgi-bin Generating the Trac cgi-bin directory], your Apache configuration file should look like following:
    8690
    87 {{{
     91{{{#!apache
    8892WSGIScriptAlias /trac /usr/share/trac/cgi-bin/trac.wsgi
    8993
     
    9599}}}
    96100
    97 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 as a result. After adding this configuration, restart Apache, and then it should work.
     101In 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.
    98102
    99103To 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):
     
    107111For 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.
    108112
    109 
    110113== Configuring Authentication
    111114
    112 We describe in the the following sections different methods for setting up authentication.
    113 
    114 See also [http://httpd.apache.org/docs/2.2/howto/auth.html Authentication, Authorization and Access Control] in the Apache guide.
    115 
    116 === Using Basic Authentication ===
    117 
    118 The simplest way to enable authentication with Apache is to create a password file. Use the `htpasswd` program to create the password file:
    119 {{{
     115The 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.
     116
     117=== Using Basic Authentication
     118
     119The simplest way to enable authentication with Apache is to create a password file. Use the `htpasswd` program as follows:
     120{{{#!sh
    120121$ htpasswd -c /somewhere/trac.htpasswd admin
    121122New password: <type password>
     
    124125}}}
    125126
    126 After the first user, you dont need the "-c" option anymore:
    127 {{{
     127After the first user, you don't need the "-c" option anymore:
     128{{{#!sh
    128129$ htpasswd /somewhere/trac.htpasswd john
    129130New password: <type password>
     
    136137After you've created the users, you can set their permissions using TracPermissions.
    137138
    138 Now, you'll need to enable authentication against the password file in the Apache configuration:
    139 {{{
     139Now, you need to enable authentication against the password file in the Apache configuration:
     140{{{#!apache
    140141<Location "/trac/login">
    141142  AuthType Basic
     
    146147}}}
    147148
    148 If you're hosting multiple projects you can use the same password file for all of them:
    149 {{{
     149If you are hosting multiple projects, you can use the same password file for all of them:
     150{{{#!apache
    150151<LocationMatch "/trac/[^/]+/login">
    151152  AuthType Basic
     
    158159See also the [http://httpd.apache.org/docs/2.2/mod/mod_auth_basic.html mod_auth_basic] documentation.
    159160
    160 === Using Digest Authentication ===
     161=== Using Digest Authentication
    161162
    162163For better security, it is recommended that you either enable SSL or at least use the “digest” authentication scheme instead of “Basic”.
    163164
    164 You'll have to create your `.htpasswd` file with the `htdigest` command instead of `htpasswd`, as follows:
    165 {{{
    166 # htdigest -c /somewhere/trac.htpasswd trac admin
     165You have to create your `.htpasswd` file with the `htdigest` command instead of `htpasswd`, as follows:
     166{{{#!sh
     167$ htdigest -c /somewhere/trac.htpasswd trac admin
    167168}}}
    168169
    169170The "trac" parameter above is the "realm", and will have to be reused in the Apache configuration in the !AuthName directive:
    170171
    171 {{{
     172{{{#!apache
    172173<Location "/trac/login">
    173 
    174     AuthType Digest
    175     AuthName "trac"
    176     AuthDigestDomain /trac
    177     AuthUserFile /somewhere/trac.htpasswd
    178     Require valid-user
     174  AuthType Digest
     175  AuthName "trac"
     176  AuthDigestDomain /trac
     177  AuthUserFile /somewhere/trac.htpasswd
     178  Require valid-user
    179179</Location>
    180180}}}
     
    185185
    186186Don't forget to activate the mod_auth_digest. For example, on a Debian 4.0r1 (etch) system:
    187 {{{
    188     LoadModule auth_digest_module /usr/lib/apache2/modules/mod_auth_digest.so
    189 }}}
    190 
     187{{{#!apache
     188  LoadModule auth_digest_module /usr/lib/apache2/modules/mod_auth_digest.so
     189}}}
    191190
    192191See also the [http://httpd.apache.org/docs/2.2/mod/mod_auth_digest.html mod_auth_digest] documentation.
     
    194193=== Using LDAP Authentication
    195194
    196 Configuration 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)
    197 
    198 1. You need to load the following modules in Apache httpd.conf
    199 {{{
    200 LoadModule ldap_module modules/mod_ldap.so
    201 LoadModule authnz_ldap_module modules/mod_authnz_ldap.so
    202 }}}
    203 
    204 2. Your httpd.conf also needs to look something like:
    205 
    206 {{{
     195Configuration 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).
     196
     1971. You need to load the following modules in Apache httpd.conf:
     198{{{#!apache
     199  LoadModule ldap_module modules/mod_ldap.so
     200  LoadModule authnz_ldap_module modules/mod_authnz_ldap.so
     201}}}
     2021. Your httpd.conf also needs to look something like:
     203{{{#!apache
    207204<Location /trac/>
    208205  # (if you're using it, mod_python specific settings go here)
     
    218215</Location>
    219216}}}
    220 
    221 
    222 3. You can use the LDAP interface as a way to authenticate to a Microsoft Active Directory:
    223 
    224 
    225 Use the following as your LDAP URL:
    226 {{{
    227     AuthLDAPURL "ldap://directory.example.com:3268/DC=example,DC=com?sAMAccountName?sub?(objectClass=user)"
    228 }}}
    229 
    230 You will also need to provide an account for Apache to use when checking
    231 credentials. As this password will be listed in plaintext in the
    232 config, you should be sure to use an account specifically for this task:
    233 {{{
    234     AuthLDAPBindDN ldap-auth-user@example.com
    235     AuthLDAPBindPassword "password"
    236 }}}
    237 
    238 The whole section looks like:
    239 {{{
     2171. You can use the LDAP interface as a way to authenticate to a Microsoft Active Directory. Use the following as your LDAP URL:
     218{{{#!apache
     219  AuthLDAPURL "ldap://directory.example.com:3268/DC=example,DC=com?sAMAccountName?sub?(objectClass=user)"
     220}}}
     221 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:
     222{{{#!apache
     223  AuthLDAPBindDN ldap-auth-user@example.com
     224  AuthLDAPBindPassword "password"
     225}}}
     226 The whole section looks like:
     227{{{#!apache
    240228<Location /trac/>
    241229  # (if you're using it, mod_python specific settings go here)
     
    251239  authzldapauthoritative Off
    252240  # require valid-user
    253   require ldap-group CN=Trac Users,CN=Users,DC=company,DC=com
    254 </Location>
    255 }}}
    256 
    257 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.
    258 
    259 Note 2: You can also require the user be a member of a certain LDAP group, instead of
    260 just having a valid login:
    261 {{{
    262     Require ldap-group CN=Trac Users,CN=Users,DC=example,DC=com
     241  Require ldap-group CN=Trac Users,CN=Users,DC=company,DC=com
     242</Location>
     243}}}
     244
     245Note 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.
     246
     247Note 2: You can also require the user be a member of a certain LDAP group, instead of just having a valid login:
     248{{{#!apache
     249  Require ldap-group CN=Trac Users,CN=Users,DC=example,DC=com
    263250}}}
    264251
    265252See also:
    266   - [http://httpd.apache.org/docs/2.2/mod/mod_authnz_ldap.html mod_authnz_ldap], documentation for mod_authnz_ldap
    267    
     253 - [http://httpd.apache.org/docs/2.2/mod/mod_authnz_ldap.html mod_authnz_ldap], documentation for mod_authnz_ldap.   
    268254 - [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.
    269255 - [http://trac-hacks.org/wiki/LdapPlugin TracHacks:LdapPlugin] for storing TracPermissions in LDAP.
     
    271257=== Using SSPI Authentication
    272258
    273 If you are using Apache on Windows, you can use mod_auth_sspi to provide
    274 single-sign-on. Download the module from the !SourceForge [http://sourceforge.net/projects/mod-auth-sspi/ mod-auth-sspi project] and then add the
    275 following to your !VirtualHost:
    276 {{{
    277     <Location /trac/login>
    278         AuthType SSPI
    279         AuthName "Trac Login"
    280         SSPIAuth On
    281         SSPIAuthoritative On
    282         SSPIDomain MyLocalDomain
    283         SSPIOfferBasic On
    284         SSPIOmitDomain Off
    285         SSPIBasicPreferred On
    286         Require valid-user
    287     </Location>
    288 }}}
    289 
    290 Using the above, usernames in Trac will be of the form `DOMAIN\username`, so
    291 you may have to re-add permissions and such. If you do not want the domain to
    292 be part of the username, set `SSPIOmitDomain On` instead.
     259If 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:
     260{{{#!apache
     261<Location /trac/login>
     262  AuthType SSPI
     263  AuthName "Trac Login"
     264  SSPIAuth On
     265  SSPIAuthoritative On
     266  SSPIDomain MyLocalDomain
     267  SSPIOfferBasic On
     268  SSPIOmitDomain Off
     269  SSPIBasicPreferred On
     270  Require valid-user
     271</Location>
     272}}}
     273
     274Using 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.
    293275
    294276Some common problems with SSPI authentication: [trac:#1055], [trac:#1168] and [trac:#3338].
     
    303285
    304286Here is an example (from the !HttpAuthStore link) using acct_mgr-0.4 for hosting a single project:
    305 {{{
     287{{{#!ini
    306288[components]
    307289; be sure to enable the component
     
    314296}}}
    315297This will generally be matched with an Apache config like:
    316 {{{
     298{{{#!apache
    317299<Location /authFile>
    318300   …HTTP authentication configuration…
     
    324306=== Example: Apache/mod_wsgi with Basic Authentication, Trac being at the root of a virtual host
    325307
    326 Per 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.
    327 
     308Per the mod_wsgi documentation linked to above, here is an example Apache configuration that:
     309 - serves the Trac instance from a virtualhost subdomain
     310 - uses Apache basic authentication for Trac authentication.
    328311
    329312If 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:
    330313
    331314Create the htpasswd file:
    332 {{{
     315{{{#!sh
    333316cd /home/trac-for-my-proj/the-env
    334317htpasswd -c htpasswd firstuser
     
    336319htpasswd htpasswd seconduser
    337320}}}
    338 (keep the file above your document root for security reasons)
    339 
    340 Create this file e.g. (ubuntu) `/etc/apache2/sites-enabled/trac.my-proj.my-site.org.conf` with the following contents:
    341 
    342 {{{
     321Keep the file above your document root for security reasons.
     322
     323Create this file e.g. (ubuntu) `/etc/apache2/sites-enabled/trac.my-proj.my-site.org.conf` with the following content:
     324
     325{{{#!apache
    343326<Directory /home/trac-for-my-proj/the-deploy/cgi-bin/trac.wsgi>
    344327  WSGIApplicationGroup %{GLOBAL}
     
    363346Note: for subdomains to work you would probably also need to alter `/etc/hosts` and add A-Records to your host's DNS.
    364347
    365 
    366348== Troubleshooting
    367349
    368350=== Use a recent version
    369351
    370 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].
     352Please 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].
    371353
    372354''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''
    373355
    374 If 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).
    375 
    376 === Getting Trac to work nicely with SSPI and 'Require Group' ===
    377 If 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'.
    378 
    379 This WSGI script 'fixes' things, hope it helps:
     356If 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.
     357
     358=== Getting Trac to work nicely with SSPI and 'Require Group'
     359
     360If 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'.
     361
     362This WSGI script 'fixes' that:
    380363{{{#!python
    381364import os
     
    391374}}}
    392375
    393 
    394 === Trac with PostgreSQL ===
    395 
    396 When 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.
    397 
    398 A 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.
    399 
    400 But it's not necessary to edit the source of Trac, the following lines in `trac.wsgi` will also work:
     376=== Trac with PostgreSQL
     377
     378When 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.
     379
     380A 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.
     381
     382But it is not necessary to edit the source of Trac. The following lines in `trac.wsgi` will also work:
    401383
    402384{{{#!python
     
    412394}}}
    413395
    414 Now Trac drops the connection after serving a page and the connection count on the database will be kept minimal.
     396Now Trac drops the connection after serving a page and the connection count on the database will be kept low.
    415397
    416398//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.//
     
    420402For 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.
    421403
    422 
    423404----
    424 See also:  TracGuide, TracInstall, [wiki:TracFastCgi FastCGI], [wiki:TracModPython ModPython], [trac:TracNginxRecipe TracNginxRecipe]
     405See also: TracGuide, TracInstall, [wiki:TracFastCgi FastCGI], [wiki:TracModPython ModPython], [trac:TracNginxRecipe TracNginxRecipe]