Changes between Version 1 and Version 2 of TracModWSGI


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Timestamp:
Jan 16, 2015, 11:29:31 AM (9 years ago)
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trac
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  • TracModWSGI

    v1 v2  
    11= Trac and mod_wsgi =
    22
    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.
     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.
    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 the following application script, which is just a Python file, though usually saved with a `.wsgi` extension.
    1110
    1211=== A very basic script
     
    2322}}}
    2423
    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.
     24The `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
     26On Windows:
     27 - If run under the user's session, the Python Egg cache can be found in `%AppData%\Roaming`, for example:
     28{{{#!python
     29os.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
     33os.environ['PYTHON_EGG_CACHE'] = r'C:\Trac-Python-Eggs'
     34}}}
    2635
    2736=== A more elaborate script
    2837
    29 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.
     38If 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.
    3039
    3140To solve this problem, use the following `.wsgi` file instead:
     
    4352For 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.
    4453
    45 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:
     54If 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:
    4655
    4756{{{#!python
     
    5463=== Recommended `trac.wsgi` script
    5564
    56 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).
    57 
     65A 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
     67If 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}}}
    5876
    5977== Mapping requests to the script
    6078
    61 After you've done preparing your .wsgi script, add the following to your Apache configuration file (`httpd.conf` for example).
     79After preparing your .wsgi script, add the following to your Apache configuration file, typically `httpd.conf`:
    6280
    6381{{{
     
    7391Here, the script is in a subdirectory of the Trac environment.
    7492
    75 If 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:
     93If you followed the directions [TracInstall#cgi-bin Generating the Trac cgi-bin directory], your Apache configuration file should look like following:
    7694
    7795{{{
     
    85103}}}
    86104
    87 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.
     105In 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.
    88106
    89107To 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):
     
    97115For 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.
    98116
    99 
    100117== Configuring Authentication
    101118
    102 We describe in the the following sections different methods for setting up authentication.
    103 
    104 See also [http://httpd.apache.org/docs/2.2/howto/auth.html Authentication, Authorization and Access Control] in the Apache guide.
     119The 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.
    105120
    106121=== Using Basic Authentication ===
    107122
    108 The simplest way to enable authentication with Apache is to create a password file. Use the `htpasswd` program to create the password file:
     123The simplest way to enable authentication with Apache is to create a password file. Use the `htpasswd` program as follows:
    109124{{{
    110125$ htpasswd -c /somewhere/trac.htpasswd admin
     
    114129}}}
    115130
    116 After the first user, you dont need the "-c" option anymore:
     131After the first user, you don't need the "-c" option anymore:
    117132{{{
    118133$ htpasswd /somewhere/trac.htpasswd john
     
    126141After you've created the users, you can set their permissions using TracPermissions.
    127142
    128 Now, you'll need to enable authentication against the password file in the Apache configuration:
     143Now, you need to enable authentication against the password file in the Apache configuration:
    129144{{{
    130145<Location "/trac/login">
     
    136151}}}
    137152
    138 If you're hosting multiple projects you can use the same password file for all of them:
     153If you are hosting multiple projects, you can use the same password file for all of them:
    139154{{{
    140155<LocationMatch "/trac/[^/]+/login">
     
    152167For better security, it is recommended that you either enable SSL or at least use the “digest” authentication scheme instead of “Basic”.
    153168
    154 You'll have to create your `.htpasswd` file with the `htdigest` command instead of `htpasswd`, as follows:
     169You have to create your `.htpasswd` file with the `htdigest` command instead of `htpasswd`, as follows:
    155170{{{
    156171# htdigest -c /somewhere/trac.htpasswd trac admin
     
    172187For multiple environments, you can use the same `LocationMatch` as described with the previous method.
    173188
     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
    174191Don't forget to activate the mod_auth_digest. For example, on a Debian 4.0r1 (etch) system:
    175192{{{
     
    177194}}}
    178195
    179 
    180196See also the [http://httpd.apache.org/docs/2.2/mod/mod_auth_digest.html mod_auth_digest] documentation.
    181197
    182198=== Using LDAP Authentication
    183199
    184 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)
    185 
    186 1. You need to load the following modules in Apache httpd.conf
     200Configuration 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
     2021. You need to load the following modules in Apache httpd.conf:
    187203{{{
    188204LoadModule ldap_module modules/mod_ldap.so
     
    207223}}}
    208224
    209 
    2102253. You can use the LDAP interface as a way to authenticate to a Microsoft Active Directory:
    211226
    212 
    213227Use the following as your LDAP URL:
    214228{{{
     
    216230}}}
    217231
    218 You will also need to provide an account for Apache to use when checking
    219 credentials. As this password will be listed in plaintext in the
    220 config, you should be sure to use an account specifically for this task:
     232You 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:
    221233{{{
    222234    AuthLDAPBindDN ldap-auth-user@example.com
     
    243255}}}
    244256
    245 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.
    246 
    247 Note 2: You can also require the user be a member of a certain LDAP group, instead of
    248 just having a valid login:
     257Note 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
     259Note 2: You can also require the user be a member of a certain LDAP group, instead of just having a valid login:
    249260{{{
    250261    Require ldap-group CN=Trac Users,CN=Users,DC=example,DC=com
     
    252263
    253264See also:
    254   - [http://httpd.apache.org/docs/2.2/mod/mod_authnz_ldap.html mod_authnz_ldap], documentation for mod_authnz_ldap
    255    
     265 - [http://httpd.apache.org/docs/2.2/mod/mod_authnz_ldap.html mod_authnz_ldap], documentation for mod_authnz_ldap.   
    256266 - [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.
    257267 - [http://trac-hacks.org/wiki/LdapPlugin TracHacks:LdapPlugin] for storing TracPermissions in LDAP.
     
    259269=== Using SSPI Authentication
    260270
    261 If you are using Apache on Windows, you can use mod_auth_sspi to provide
    262 single-sign-on. Download the module from the !SourceForge [http://sourceforge.net/projects/mod-auth-sspi/ mod-auth-sspi project] and then add the
    263 following to your !VirtualHost:
     271If 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:
    264272{{{
    265273    <Location /trac/login>
     
    276284}}}
    277285
    278 Using the above, usernames in Trac will be of the form `DOMAIN\username`, so
    279 you may have to re-add permissions and such. If you do not want the domain to
    280 be part of the username, set `SSPIOmitDomain On` instead.
     286Using 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.
    281287
    282288Some common problems with SSPI authentication: [trac:#1055], [trac:#1168] and [trac:#3338].
     
    308314</Location>
    309315}}}
    310 Note that '''authFile''' need not exist. See the !HttpAuthStore link above for examples where multiple Trac projects are hosted on a server.
     316Note 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.
    311317
    312318=== Example: Apache/mod_wsgi with Basic Authentication, Trac being at the root of a virtual host
    313319
    314 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.
    315 
     320Per 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.
    316323
    317324If 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:
     
    324331htpasswd htpasswd seconduser
    325332}}}
    326 (keep the file above your document root for security reasons)
    327 
    328 Create this file e.g. (ubuntu) `/etc/apache2/sites-enabled/trac.my-proj.my-site.org.conf` with the following contents:
     333Keep the file above your document root for security reasons.
     334
     335Create this file e.g. (ubuntu) `/etc/apache2/sites-enabled/trac.my-proj.my-site.org.conf` with the following content:
    329336
    330337{{{
     
    351358Note: for subdomains to work you would probably also need to alter `/etc/hosts` and add A-Records to your host's DNS.
    352359
    353 
    354360== Troubleshooting
    355361
    356362=== Use a recent version
    357363
    358 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].
     364Please 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].
    359365
    360366''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''
    361367
    362 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).
     368If 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.
    363369
    364370=== Getting Trac to work nicely with SSPI and 'Require Group' ===
    365 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'.
    366 
    367 This WSGI script 'fixes' things, hope it helps:
     371
     372If 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
     374This WSGI script 'fixes' that:
    368375{{{#!python
    369376import os
     
    379386}}}
    380387
    381 
    382388=== Trac with PostgreSQL ===
    383389
    384 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.
    385 
    386 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.
    387 
    388 But it's not necessary to edit the source of Trac, the following lines in `trac.wsgi` will also work:
    389 
    390 {{{
     390When 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
     392A 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
     394But it is not necessary to edit the source of Trac. The following lines in `trac.wsgi` will also work:
     395
     396{{{#!python
    391397import trac.db.postgres_backend
    392398trac.db.postgres_backend.PostgreSQLConnection.poolable = False
     
    395401or
    396402
    397 {{{
     403{{{#!python
    398404import trac.db.mysql_backend
    399405trac.db.mysql_backend.MySQLConnection.poolable = False
    400406}}}
    401407
    402 Now Trac drops the connection after serving a page and the connection count on the database will be kept minimal.
     408Now Trac drops the connection after serving a page and the connection count on the database will be kept low.
    403409
    404410//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.//
     
    408414For 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.
    409415
    410 
    411416----
    412 See also:  TracGuide, TracInstall, [wiki:TracFastCgi FastCGI], [wiki:TracModPython ModPython], [trac:TracNginxRecipe TracNginxRecipe]
     417See also: TracGuide, TracInstall, [wiki:TracFastCgi FastCGI], [wiki:TracModPython ModPython], [trac:TracNginxRecipe TracNginxRecipe]