Changes between Version 2 and Version 3 of TracModWSGI


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Timestamp:
Jan 13, 2020, 11:54:45 PM (5 years ago)
Author:
trac
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  • TracModWSGI

    v2 v3  
    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 performances.
     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 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 (note that this directory should contain //only// Trac environments, no other sub-directories):
     14{{{#!python
     15def application(environ, start_request):
     16    # Add this when you have multiple projects
     17    environ.setdefault('trac.env_parent_dir', '/usr/share/trac/projects') 
     18    ..
     19}}}
    1120
    1221=== A very basic script
     22
    1323In its simplest form, the script could be:
    1424
    … …  
    2333}}}
    2434
    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.
     35The `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`.
     36
     37On Windows:
     38 - If run under the user's session, the Python Egg cache can be found in `%AppData%\Roaming`, for example:
     39{{{#!python
     40os.environ['PYTHON_EGG_CACHE'] = r'C:\Users\Administrator\AppData\Roaming\Python-Eggs'
     41}}}
     42 - If run under a Window service, you should create a directory for Python Egg cache:
     43{{{#!python
     44os.environ['PYTHON_EGG_CACHE'] = r'C:\Trac-Python-Eggs'
     45}}}
    2646
    2747=== A more elaborate script
    2848
    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.
     49If 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.
    3050
    3151To solve this problem, use the following `.wsgi` file instead:
    … …  
    4363For 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.
    4464
    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:
     65If 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:
    4666
    4767{{{#!python
    … …  
    5272Change it according to the path you installed the Trac libs at.
    5373
    54 === Recommended `trac.wsgi` script
    55 
    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 
    58 
    5974== Mapping requests to the script
    6075
    61 After you've done preparing your .wsgi script, add the following to your Apache configuration file (`httpd.conf` for example).
    62 
    63 {{{
     76After preparing your .wsgi script, add the following to your Apache configuration file, typically `httpd.conf`:
     77
     78{{{#!apache
    6479WSGIScriptAlias /trac /usr/local/trac/mysite/apache/mysite.wsgi
    6580
    6681<Directory /usr/local/trac/mysite/apache>
    6782    WSGIApplicationGroup %{GLOBAL}
    68     Order deny,allow
    69     Allow from all
     83    # For Apache 2.2
     84    <IfModule !mod_authz_core.c>
     85        Order deny,allow
     86        Allow from all
     87    </IfModule>
     88    # For Apache 2.4
     89    <IfModule mod_authz_core.c>
     90        Require all granted
     91    </IfModule>
    7092</Directory>
    7193}}}
    … …  
    7395Here, the script is in a subdirectory of the Trac environment.
    7496
    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:
    76 
    77 {{{
     97If you followed the directions [TracInstall#cgi-bin Generating the Trac cgi-bin directory], your Apache configuration file should look like following:
     98
     99{{{#!apache
    78100WSGIScriptAlias /trac /usr/share/trac/cgi-bin/trac.wsgi
    79101
    80102<Directory /usr/share/trac/cgi-bin>
    81103    WSGIApplicationGroup %{GLOBAL}
    82     Order deny,allow
    83     Allow from all
     104    # For Apache 2.2
     105    <IfModule !mod_authz_core.c>
     106        Order deny,allow
     107        Allow from all
     108    </IfModule>
     109    # For Apache 2.4
     110    <IfModule mod_authz_core.c>
     111        Require all granted
     112    </IfModule>
    84113</Directory>
    85114}}}
    86115
    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.
    88 
    89 To 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):
     116In 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.
     117
     118To 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):
    90119
    91120{{{#!python
    … …  
    95124}}}
    96125
    97 For 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.
    98 
     126For more information about using the mod_wsgi specific directives, see the [https://code.google.com/archive/p/modwsgi/wikis mod_wsgi's wiki] and more specifically the [https://code.google.com/archive/p/modwsgi/wikis/IntegrationWithTrac.wiki IntegrationWithTrac] page.
    99127
    100128== Configuring Authentication
    101129
    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.
    105 
    106 === Using Basic Authentication ===
    107 
    108 The simplest way to enable authentication with Apache is to create a password file. Use the `htpasswd` program to create the password file:
    109 {{{
     130The following sections describe different methods for setting up authentication. See also [http://httpd.apache.org/docs/2.4/howto/auth.html Authentication, Authorization and Access Control] in the Apache guide.
     131
     132=== Using Basic Authentication
     133
     134The simplest way to enable authentication with Apache is to create a password file. Use the `htpasswd` program as follows:
     135{{{#!sh
    110136$ htpasswd -c /somewhere/trac.htpasswd admin
    111137New password: <type password>
    … …  
    114140}}}
    115141
    116 After the first user, you dont need the "-c" option anymore:
    117 {{{
     142After the first user, you don't need the "-c" option anymore:
     143{{{#!sh
    118144$ htpasswd /somewhere/trac.htpasswd john
    119145New password: <type password>
    … …  
    122148}}}
    123149
    124   ''See the man page for `htpasswd` for full documentation.''
     150See the man page for `htpasswd` for full documentation.
    125151
    126152After you've created the users, you can set their permissions using TracPermissions.
    127153
    128 Now, you'll need to enable authentication against the password file in the Apache configuration:
    129 {{{
     154Now, you need to enable authentication against the password file in the Apache configuration:
     155{{{#!apache
    130156<Location "/trac/login">
    131157  AuthType Basic
    … …  
    136162}}}
    137163
    138 If you're hosting multiple projects you can use the same password file for all of them:
    139 {{{
     164If you are hosting multiple projects, you can use the same password file for all of them:
     165{{{#!apache
    140166<LocationMatch "/trac/[^/]+/login">
    141167  AuthType Basic
    … …  
    145171</LocationMatch>
    146172}}}
    147 Note that neither a file nor a directory named 'login' needs to exist.[[BR]]
    148 See also the [http://httpd.apache.org/docs/2.2/mod/mod_auth_basic.html mod_auth_basic] documentation.
    149 
    150 === Using Digest Authentication ===
    151 
    152 For better security, it is recommended that you either enable SSL or at least use the “digest” authentication scheme instead of “Basic”.
    153 
    154 You'll have to create your `.htpasswd` file with the `htdigest` command instead of `htpasswd`, as follows:
    155 {{{
    156 # htdigest -c /somewhere/trac.htpasswd trac admin
     173
     174Note that neither a file nor a directory named 'login' needs to exist. See also the [https://httpd.apache.org/docs/2.4/mod/mod_auth_basic.html mod_auth_basic] documentation.
     175
     176=== Using Digest Authentication
     177
     178For better security, it is recommended that you either enable SSL or at least use the "digest" authentication scheme instead of "Basic".
     179
     180You have to create your `.htpasswd` file with the `htdigest` command instead of `htpasswd`, as follows:
     181{{{#!sh
     182$ htdigest -c /somewhere/trac.htpasswd trac admin
    157183}}}
    158184
    159185The "trac" parameter above is the "realm", and will have to be reused in the Apache configuration in the !AuthName directive:
    160186
    161 {{{
     187{{{#!apache
    162188<Location "/trac/login">
    163 
    164     AuthType Digest
    165     AuthName "trac"
    166     AuthDigestDomain /trac
    167     AuthUserFile /somewhere/trac.htpasswd
    168     Require valid-user
     189  AuthType Digest
     190  AuthName "trac"
     191  AuthDigestDomain /trac
     192  AuthUserFile /somewhere/trac.htpasswd
     193  Require valid-user
    169194</Location>
    170195}}}
    … …  
    172197For multiple environments, you can use the same `LocationMatch` as described with the previous method.
    173198
     199'''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.
     200
    174201Don't forget to activate the mod_auth_digest. For example, on a Debian 4.0r1 (etch) system:
    175 {{{
    176     LoadModule auth_digest_module /usr/lib/apache2/modules/mod_auth_digest.so
    177 }}}
    178 
    179 
    180 See also the [http://httpd.apache.org/docs/2.2/mod/mod_auth_digest.html mod_auth_digest] documentation.
     202{{{#!apache
     203  LoadModule auth_digest_module /usr/lib/apache2/modules/mod_auth_digest.so
     204}}}
     205
     206See also the [https://httpd.apache.org/docs/2.4/mod/mod_auth_basic.html mod_auth_digest] documentation.
    181207
    182208=== Using LDAP Authentication
    183209
    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
    187 {{{
    188 LoadModule ldap_module modules/mod_ldap.so
    189 LoadModule authnz_ldap_module modules/mod_authnz_ldap.so
    190 }}}
    191 
    192 2. Your httpd.conf also needs to look something like:
    193 
    194 {{{
     210Configuration for [https://httpd.apache.org/docs/2.4/mod/mod_ldap.html mod_ldap] authentication in Apache is more involved (httpd 2.2+ and OpenLDAP: slapd 2.3.19).
     211
     2121. You need to load the following modules in Apache httpd.conf:
     213{{{#!apache
     214  LoadModule ldap_module modules/mod_ldap.so
     215  LoadModule authnz_ldap_module modules/mod_authnz_ldap.so
     216}}}
     2171. Your httpd.conf also needs to look something like:
     218{{{#!apache
    195219<Location /trac/>
    196220  # (if you're using it, mod_python specific settings go here)
    … …  
    206230</Location>
    207231}}}
    208 
    209 
    210 3. You can use the LDAP interface as a way to authenticate to a Microsoft Active Directory:
    211 
    212 
    213 Use the following as your LDAP URL:
    214 {{{
    215     AuthLDAPURL "ldap://directory.example.com:3268/DC=example,DC=com?sAMAccountName?sub?(objectClass=user)"
    216 }}}
    217 
    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:
    221 {{{
    222     AuthLDAPBindDN ldap-auth-user@example.com
    223     AuthLDAPBindPassword "password"
    224 }}}
    225 
    226 The whole section looks like:
    227 {{{
     2321. You can use the LDAP interface as a way to authenticate to a Microsoft Active Directory. Use the following as your LDAP URL:
     233{{{#!apache
     234  AuthLDAPURL "ldap://directory.example.com:3268/DC=example,DC=com?sAMAccountName?sub?(objectClass=user)"
     235}}}
     236 You will also need to provide an account for Apache to use when checking credentials. As this password will be listed in plain text in the configuration, you need to use an account specifically for this task:
     237{{{#!apache
     238  AuthLDAPBindDN ldap-auth-user@example.com
     239  AuthLDAPBindPassword "password"
     240}}}
     241 The whole section looks like:
     242{{{#!apache
    228243<Location /trac/>
    229244  # (if you're using it, mod_python specific settings go here)
    … …  
    239254  authzldapauthoritative Off
    240255  # require valid-user
    241   require ldap-group CN=Trac Users,CN=Users,DC=company,DC=com
     256  Require ldap-group CN=Trac Users,CN=Users,DC=company,DC=com
    242257</Location>
    243258}}}
    244259
    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:
    249 {{{
    250     Require ldap-group CN=Trac Users,CN=Users,DC=example,DC=com
     260Note 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.
     261
     262Note 2: You can also require the user be a member of a certain LDAP group, instead of just having a valid login:
     263{{{#!apache
     264  Require ldap-group CN=Trac Users,CN=Users,DC=example,DC=com
    251265}}}
    252266
    253267See also:
    254   - [http://httpd.apache.org/docs/2.2/mod/mod_authnz_ldap.html mod_authnz_ldap], documentation for mod_authnz_ldap
    255    
    256  - [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.
    257  - [http://trac-hacks.org/wiki/LdapPlugin TracHacks:LdapPlugin] for storing TracPermissions in LDAP.
     268 - [https://httpd.apache.org/docs/2.4/mod/mod_authnz_ldap.html mod_authnz_ldap], documentation for mod_authnz_ldap.   
     269 - [https://httpd.apache.org/docs/2.4/mod/mod_ldap.html mod_ldap], documentation for mod_ldap, which provides connection pooling and a shared cache.
     270 - [https://trac-hacks.org/wiki/LdapPlugin TracHacks:LdapPlugin] for storing TracPermissions in LDAP.
    258271
    259272=== Using SSPI Authentication
    260273
    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:
    264 {{{
    265     <Location /trac/login>
    266         AuthType SSPI
    267         AuthName "Trac Login"
    268         SSPIAuth On
    269         SSPIAuthoritative On
    270         SSPIDomain MyLocalDomain
    271         SSPIOfferBasic On
    272         SSPIOmitDomain Off
    273         SSPIBasicPreferred On
    274         Require valid-user
    275     </Location>
    276 }}}
    277 
    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.
     274If 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:
     275{{{#!apache
     276<Location /trac/login>
     277  AuthType SSPI
     278  AuthName "Trac Login"
     279  SSPIAuth On
     280  SSPIAuthoritative On
     281  SSPIDomain MyLocalDomain
     282  SSPIOfferBasic On
     283  SSPIOmitDomain Off
     284  SSPIBasicPreferred On
     285  Require valid-user
     286</Location>
     287}}}
     288
     289Using 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.
    281290
    282291Some common problems with SSPI authentication: [trac:#1055], [trac:#1168] and [trac:#3338].
    … …  
    284293See also [trac:TracOnWindows/Advanced].
    285294
    286 === Using Apache authentication with the Account Manager plugin's Login form ===
    287 
    288 To 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].
    289 
    290 '''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.
    291 
    292 Here is an example (from the !HttpAuthStore link) using acct_mgr-0.4 for hosting a single project:
    293 {{{
    294 [components]
    295 ; be sure to enable the component
    296 acct_mgr.http.HttpAuthStore = enabled
    297 
    298 [account-manager]
    299 ; configure the plugin to use a page that is secured with http authentication
    300 authentication_url = /authFile
    301 password_store = HttpAuthStore
    302 }}}
    303 This will generally be matched with an Apache config like:
    304 {{{
    305 <Location /authFile>
    306    …HTTP authentication configuration…
    307    Require valid-user
    308 </Location>
    309 }}}
    310 Note that '''authFile''' need not exist. See the !HttpAuthStore link above for examples where multiple Trac projects are hosted on a server.
     295=== Using CA !SiteMinder Authentication
     296
     297Setup CA !SiteMinder to protect your Trac login URL, for example `/trac/login`. Also, make sure the policy is set to include the HTTP_REMOTE_USER variable. If your site allows it, you can set this in `LocalConfig.conf`:
     298{{{#!apache
     299RemoteUserVar="WHATEVER_IT_SHOULD_BE"
     300SetRemoteUser="YES"
     301}}}
     302
     303The specific variable is site-dependent. Ask your site administrator. If your site does not allow the use of `LocalConfig.conf` for security reasons, have your site administrator set the policy on the server to set REMOTE_USER.
     304
     305Also add a !LogOffUri parameter to the agent configuration, for example `/trac/logout`.
     306
     307Then modify the trac.wsgi script generated using `trac-admin <env> deploy <dir>` to add the following lines, which extract the `HTTP_REMOTE_USER` variable and set it to `REMOTE_USER`:
     308
     309{{{#!python
     310def application(environ, start_request):
     311    # Set authenticated username on CA SiteMinder to REMOTE_USER variable
     312    # strip() is used to remove any spaces on the end of the string
     313    if 'HTTP_SM_USER' in environ:
     314        environ['REMOTE_USER'] = environ['HTTP_REMOTE_USER'].strip()
     315    ...
     316}}}
     317
     318You do not need any Apache "Location" directives.
    311319
    312320=== Example: Apache/mod_wsgi with Basic Authentication, Trac being at the root of a virtual host
    313321
    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 
    316 
    317 If 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:
     322Per the mod_wsgi documentation linked to above, here is an example Apache configuration that:
     323 - serves the Trac instance from a virtualhost subdomain
     324 - uses Apache basic authentication for Trac authentication.
     325
     326If you want your Trac to be served from eg !http://trac.my-proj.my-site.org, then from the folder eg `/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:
    318327
    319328Create the htpasswd file:
    320 {{{
     329{{{#!sh
    321330cd /home/trac-for-my-proj/the-env
    322331htpasswd -c htpasswd firstuser
    … …  
    324333htpasswd htpasswd seconduser
    325334}}}
    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:
    329 
    330 {{{
     335
     336Keep the file above your document root for security reasons.
     337
     338Create this file for example `/etc/apache2/sites-enabled/trac.my-proj.my-site.org.conf` on Ubuntu with the following content:
     339
     340{{{#!apache
    331341<Directory /home/trac-for-my-proj/the-deploy/cgi-bin/trac.wsgi>
    332342  WSGIApplicationGroup %{GLOBAL}
    … …  
    349359}}}
    350360
    351 Note: for subdomains to work you would probably also need to alter `/etc/hosts` and add A-Records to your host's DNS.
    352 
     361For subdomains to work you would probably also need to alter `/etc/hosts` and add A-Records to your host's DNS.
    353362
    354363== Troubleshooting
    … …  
    356365=== Use a recent version
    357366
    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].
    359 
    360 ''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''
    361 
    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).
    363 
    364 === 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:
     367Please 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 [https://code.google.com/archive/p/modwsgi/issues/100 #100] and [https://code.google.com/archive/p/modwsgi/issues/132 #132].
     368
     369'''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
     370
     371If 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.
     372
     373=== Getting Trac to work nicely with SSPI and 'Require Group'
     374
     375If 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'.
     376
     377This WSGI script fixes that:
    368378{{{#!python
    369379import os
    … …  
    379389}}}
    380390
    381 
    382 === Trac with PostgreSQL ===
    383 
    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 {{{
     391=== Trac with PostgreSQL
     392
     393When 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.
     394
     395A 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.
     396
     397But it is not necessary to edit the source of Trac. The following lines in `trac.wsgi` will also work:
     398
     399{{{#!python
    391400import trac.db.postgres_backend
    392401trac.db.postgres_backend.PostgreSQLConnection.poolable = False
    … …  
    395404or
    396405
    397 {{{
     406{{{#!python
    398407import trac.db.mysql_backend
    399408trac.db.mysql_backend.MySQLConnection.poolable = False
    400409}}}
    401410
    402 Now Trac drops the connection after serving a page and the connection count on the database will be kept minimal.
    403 
    404 //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.//
     411Now Trac drops the connection after serving a page and the connection count on the database will be kept low.
     412
     413//This is not a recommended approach though. See also the notes at the bottom of the [https://code.google.com/archive/p/modwsgi/wikis/IntegrationWithTrac.wiki mod_wsgi's IntegrationWithTrac] wiki page.//
     414
     415=== Missing Headers and Footers
     416
     417If python optimizations are enabled, then headers and footers will not be rendered. An error will be raised in Trac 1.0.11 and later when optimizations are enabled.
     418
     419In your WSGI configuration file, the `WSGIPythonOptimize` setting must be set to `0` (`1` or `2` will not work):
     420
     421{{{#!apache
     422    WSGIPythonOptimize 0
     423}}}
     424
     425On Ubuntu, the WSGI mod configuration is at `/etc/apache2/mods-enabled/wsgi.conf`.
     426
     427The same issue is seen with `PythonOptimize On` in [TracModPython#Pagelayoutissues ModPython].
    405428
    406429=== Other resources
    407430
    408 For 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.
    409 
     431For more troubleshooting tips, see also the [TracModPython#Troubleshooting mod_python troubleshooting] section, as most Apache-related issues are quite similar, plus discussion of potential [https://code.google.com/archive/p/modwsgi/wikis/ApplicationIssues.wiki application issues] when using mod_wsgi. The wsgi page also has a [https://code.google.com/archive/p/modwsgi/wikis/IntegrationWithTrac.wiki Integration With Trac] document.
    410432
    411433----
    412 See also:  TracGuide, TracInstall, [wiki:TracFastCgi FastCGI], [wiki:TracModPython ModPython], [trac:TracNginxRecipe TracNginxRecipe]
     434See also: TracGuide, TracInstall, [wiki:TracFastCgi FastCGI], [wiki:TracModPython ModPython], [trac:TracNginxRecipe TracNginxRecipe]