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     1= Trac and mod_wsgi
     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.
     7== The `trac.wsgi` script
     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.
     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].
     13If you are using Trac with multiple projects, you can specify their common parent directory using the `TRAC_ENV_PARENT_DIR` in trac.wsgi:
     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    ..
     21=== A very basic script
     22In its simplest form, the script could be:
     25import os
     27os.environ['TRAC_ENV'] = '/usr/local/trac/mysite'
     28os.environ['PYTHON_EGG_CACHE'] = '/usr/local/trac/mysite/eggs'
     30import trac.web.main
     31application = trac.web.main.dispatch_request
     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`.
     36On Windows:
     37 - If run under the user's session, the Python Egg cache can be found in `%AppData%\Roaming`, for example:
     39os.environ['PYTHON_EGG_CACHE'] = r'C:\Users\Administrator\AppData\Roaming\Python-Eggs'
     41 - If run under a Window service, you should create a directory for Python Egg cache:
     43os.environ['PYTHON_EGG_CACHE'] = r'C:\Trac-Python-Eggs'
     46=== A more elaborate script
     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.
     50To solve this problem, use the following `.wsgi` file instead:
     52import os
     54os.environ['PYTHON_EGG_CACHE'] = '/usr/local/trac/mysite/eggs'
     56import trac.web.main
     57def application(environ, start_response):
     58  environ['trac.env_path'] = '/usr/local/trac/mysite'
     59  return trac.web.main.dispatch_request(environ, start_response)
     62For 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.
     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:
     67import site
     71Change it according to the path you installed the Trac libs at.
     73== Mapping requests to the script
     75After preparing your .wsgi script, add the following to your Apache configuration file, typically `httpd.conf`:
     78WSGIScriptAlias /trac /usr/local/trac/mysite/apache/mysite.wsgi
     80<Directory /usr/local/trac/mysite/apache>
     81    WSGIApplicationGroup %{GLOBAL}
     82    Order deny,allow
     83    Allow from all
     87Here, the script is in a subdirectory of the Trac environment.
     89If you followed the directions [TracInstall#cgi-bin Generating the Trac cgi-bin directory], your Apache configuration file should look like following:
     92WSGIScriptAlias /trac /usr/share/trac/cgi-bin/trac.wsgi
     94<Directory /usr/share/trac/cgi-bin>
     95    WSGIApplicationGroup %{GLOBAL}
     96    Order deny,allow
     97    Allow from all
     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.
     103To 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):
     106def application(environ, start_response):
     107        start_response('200 OK',[('Content-type','text/html')])
     108        return ['<html><body>Hello World!</body></html>']
     111For 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.
     113== Configuring Authentication
     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.
     117=== Using Basic Authentication
     119The simplest way to enable authentication with Apache is to create a password file. Use the `htpasswd` program as follows:
     121$ htpasswd -c /somewhere/trac.htpasswd admin
     122New password: <type password>
     123Re-type new password: <type password again>
     124Adding password for user admin
     127After the first user, you don't need the "-c" option anymore:
     129$ htpasswd /somewhere/trac.htpasswd john
     130New password: <type password>
     131Re-type new password: <type password again>
     132Adding password for user john
     135  ''See the man page for `htpasswd` for full documentation.''
     137After you've created the users, you can set their permissions using TracPermissions.
     139Now, you need to enable authentication against the password file in the Apache configuration:
     141<Location "/trac/login">
     142  AuthType Basic
     143  AuthName "Trac"
     144  AuthUserFile /somewhere/trac.htpasswd
     145  Require valid-user
     149If you are hosting multiple projects, you can use the same password file for all of them:
     151<LocationMatch "/trac/[^/]+/login">
     152  AuthType Basic
     153  AuthName "Trac"
     154  AuthUserFile /somewhere/trac.htpasswd
     155  Require valid-user
     158Note that neither a file nor a directory named 'login' needs to exist.[[BR]]
     159See also the [http://httpd.apache.org/docs/2.2/mod/mod_auth_basic.html mod_auth_basic] documentation.
     161=== Using Digest Authentication
     163For better security, it is recommended that you either enable SSL or at least use the “digest” authentication scheme instead of “Basic”.
     165You have to create your `.htpasswd` file with the `htdigest` command instead of `htpasswd`, as follows:
     167$ htdigest -c /somewhere/trac.htpasswd trac admin
     170The "trac" parameter above is the "realm", and will have to be reused in the Apache configuration in the !AuthName directive:
     173<Location "/trac/login">
     174  AuthType Digest
     175  AuthName "trac"
     176  AuthDigestDomain /trac
     177  AuthUserFile /somewhere/trac.htpasswd
     178  Require valid-user
     182For multiple environments, you can use the same `LocationMatch` as described with the previous method.
     184'''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. '''
     186Don't forget to activate the mod_auth_digest. For example, on a Debian 4.0r1 (etch) system:
     188  LoadModule auth_digest_module /usr/lib/apache2/modules/mod_auth_digest.so
     191See also the [http://httpd.apache.org/docs/2.2/mod/mod_auth_digest.html mod_auth_digest] documentation.
     193=== Using LDAP Authentication
     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).
     1971. You need to load the following modules in Apache httpd.conf:
     199  LoadModule ldap_module modules/mod_ldap.so
     200  LoadModule authnz_ldap_module modules/mod_authnz_ldap.so
     2021. Your httpd.conf also needs to look something like:
     204<Location /trac/>
     205  # (if you're using it, mod_python specific settings go here)
     206  Order deny,allow
     207  Deny from all
     208  Allow from
     209  AuthType Basic
     210  AuthName "Trac"
     211  AuthBasicProvider "ldap"
     212  AuthLDAPURL "ldap://,dc=co,dc=ke?uid?sub?(objectClass=inetOrgPerson)"
     213  authzldapauthoritative Off
     214  Require valid-user
     2171. You can use the LDAP interface as a way to authenticate to a Microsoft Active Directory. Use the following as your LDAP URL:
     219  AuthLDAPURL "ldap://directory.example.com:3268/DC=example,DC=com?sAMAccountName?sub?(objectClass=user)"
     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:
     223  AuthLDAPBindDN ldap-auth-user@example.com
     224  AuthLDAPBindPassword "password"
     226 The whole section looks like:
     228<Location /trac/>
     229  # (if you're using it, mod_python specific settings go here)
     230  Order deny,allow
     231  Deny from all
     232  Allow from
     233  AuthType Basic
     234  AuthName "Trac"
     235  AuthBasicProvider "ldap"
     236  AuthLDAPURL "ldap://adserver.company.com:3268/DC=company,DC=com?sAMAccountName?sub?(objectClass=user)"
     237  AuthLDAPBindDN       ldap-auth-user@company.com
     238  AuthLDAPBindPassword "the_password"
     239  authzldapauthoritative Off
     240  # require valid-user
     241  Require ldap-group CN=Trac Users,CN=Users,DC=company,DC=com
     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.
     247Note 2: You can also require the user be a member of a certain LDAP group, instead of just having a valid login:
     249  Require ldap-group CN=Trac Users,CN=Users,DC=example,DC=com
     252See also:
     253 - [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_ldap.html mod_ldap], documentation for mod_ldap, which provides connection pooling and a shared cache.
     255 - [http://trac-hacks.org/wiki/LdapPlugin TracHacks:LdapPlugin] for storing TracPermissions in LDAP.
     257=== Using SSPI Authentication
     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:
     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
     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.
     276Some common problems with SSPI authentication: [trac:#1055], [trac:#1168] and [trac:#3338].
     278See also [trac:TracOnWindows/Advanced].
     280=== Using Apache authentication with the Account Manager plugin's Login form ===
     282To begin with, see the basic instructions for using the Account Manager plugin's [http://trac-hacks.org/wiki/AccountManagerPlugin/Modules#LoginModule Login module] and its [http://trac-hacks.org/wiki/AccountManagerPlugin/AuthStores#HttpAuthStore HttpAuthStore authentication module].
     284'''Note:''' If is difficult to get !HttpAuthStore to work with WSGI when using any Account Manager version prior to acct_mgr-0.4. Upgrading is recommended.
     286Here is an example (from the !HttpAuthStore link) using acct_mgr-0.4 for hosting a single project:
     289; be sure to enable the component
     290acct_mgr.http.HttpAuthStore = enabled
     293; configure the plugin to use a page that is secured with http authentication
     294authentication_url = /authFile
     295password_store = HttpAuthStore
     297This will generally be matched with an Apache config like:
     299<Location /authFile>
     300   …HTTP authentication configuration…
     301   Require valid-user
     304Note 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.
     306=== Example: Apache/mod_wsgi with Basic Authentication, Trac being at the root of a virtual host
     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.
     312If 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:
     314Create the htpasswd file:
     316cd /home/trac-for-my-proj/the-env
     317htpasswd -c htpasswd firstuser
     318### and add more users to it as needed:
     319htpasswd htpasswd seconduser
     321Keep the file above your document root for security reasons.
     323Create this file e.g. (ubuntu) `/etc/apache2/sites-enabled/trac.my-proj.my-site.org.conf` with the following content:
     326<Directory /home/trac-for-my-proj/the-deploy/cgi-bin/trac.wsgi>
     327  WSGIApplicationGroup %{GLOBAL}
     328  Order deny,allow
     329  Allow from all
     332<VirtualHost *:80>
     333  ServerName trac.my-proj.my-site.org
     334  DocumentRoot /home/trac-for-my-proj/the-env/htdocs/
     335  WSGIScriptAlias / /home/trac-for-my-proj/the-deploy/cgi-bin/trac.wsgi
     336  <Location '/'>
     337    AuthType Basic
     338    AuthName "Trac"
     339    AuthUserFile /home/trac-for-my-proj/the-env/htpasswd
     340    Require valid-user
     341  </Location>
     346Note: for subdomains to work you would probably also need to alter `/etc/hosts` and add A-Records to your host's DNS.
     348== Troubleshooting
     350=== Use a recent version
     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].
     354''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 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''
     356If you plan to use `mod_wsgi` in embedded mode on Windows or with the MPM worker on Linux, then you will need version 3.4 or greater. See [trac:#10675] for details.
     358=== Getting Trac to work nicely with SSPI and 'Require Group'
     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'.
     362This WSGI script 'fixes' that:
     364import os
     365import trac.web.main
     367os.environ['TRAC_ENV'] = '/usr/local/trac/mysite'
     368os.environ['PYTHON_EGG_CACHE'] = '/usr/local/trac/mysite/eggs'
     370def application(environ, start_response):
     371    if "\\" in environ['REMOTE_USER']:
     372        environ['REMOTE_USER'] = environ['REMOTE_USER'].split("\\", 1)[1]
     373    return trac.web.main.dispatch_request(environ, start_response)
     376=== Trac with PostgreSQL
     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.
     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.
     382But it is not necessary to edit the source of Trac. The following lines in `trac.wsgi` will also work:
     385import trac.db.postgres_backend
     386trac.db.postgres_backend.PostgreSQLConnection.poolable = False
     392import trac.db.mysql_backend
     393trac.db.mysql_backend.MySQLConnection.poolable = False
     396Now Trac drops the connection after serving a page and the connection count on the database will be kept low.
     398//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.//
     400=== Other resources
     402For 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.
     405See also: TracGuide, TracInstall, [wiki:TracFastCgi FastCGI], [wiki:TracModPython ModPython], [trac:TracNginxRecipe TracNginxRecipe]
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