Changes between Version 1 and Version 2 of TracModWSGI
- Timestamp:
- 04/22/15 15:35:16 (10 years ago)
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TracModWSGI
v1 v2 1 = Trac and mod_wsgi = 2 3 '''Important note:''' ''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. 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].'' 4 5 [http://code.google.com/p/modwsgi/ mod_wsgi] is an Apache module for running WSGI-compatible Python applications directly on top of Apache. The mod_wsgi adapter is written completely in C and provides significantly better performance than using existing WSGI adapters for mod_python or CGI. 6 7 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). This file can be created using '''trac-admin <env> deploy <dir>''' command which automatically substitutes required paths. 8 9 {{{ 10 #!python 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. 4 5 [[PageOutline(2-3,Overview,inline)]] 6 7 == The `trac.wsgi` script 8 9 Trac 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 11 A 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 13 If 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 15 def 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 }}} 20 21 === A very basic script 22 In its simplest form, the script could be: 23 24 {{{#!python 11 25 import os 12 26 … … 18 32 }}} 19 33 20 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. 21 22 '''Important note:''' 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. (The variable may be filled with the path of a previously viewed Trac environment.) To solve this problem, use the following `.wsgi` file instead: 23 24 {{{ 25 #!python 34 The `TRAC_ENV` variable should naturally be the directory for your Trac environment, and the `PYTHON_EGG_CACHE` should be a directory where Python can temporarily extract Python eggs. If you have several Trac environments in a directory, you can also use `TRAC_ENV_PARENT_DIR` instead of `TRAC_ENV`. 35 36 On Windows: 37 - If run under the user's session, the Python Egg cache can be found in `%AppData%\Roaming`, for example: 38 {{{#!python 39 os.environ['PYTHON_EGG_CACHE'] = r'C:\Users\Administrator\AppData\Roaming\Python-Eggs' 40 }}} 41 - If run under a Window service, you should create a directory for Python Egg cache: 42 {{{#!python 43 os.environ['PYTHON_EGG_CACHE'] = r'C:\Trac-Python-Eggs' 44 }}} 45 46 === A more elaborate script 47 48 If you are using multiple `.wsgi` files (for example one per Trac environment) you must ''not'' use `os.environ['TRAC_ENV']` to set the path to the Trac environment. Using this method may lead to Trac delivering the content of another Trac environment, as the variable may be filled with the path of a previously viewed Trac environment. 49 50 To solve this problem, use the following `.wsgi` file instead: 51 {{{#!python 26 52 import os 27 53 … … 34 60 }}} 35 61 36 For clarity, you should give this file a `.wsgi` extension. You should probably put the file in it's own directory, since you will open up its directory to Apache. You can create a .wsgi files which handles all this for you by running the TracAdmin command `deploy`. 37 38 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 on top of the wsgi script: 39 40 {{{ 41 #!python 62 For 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. 63 64 If you have installed Trac and Python eggs in a path different from the standard one, you should add that path by adding the following code at the top of the wsgi script: 65 66 {{{#!python 42 67 import site 43 68 site.addsitedir('/usr/local/trac/lib/python2.4/site-packages') 44 69 }}} 45 70 46 Change it according to the path you installed the trac libs at. 47 48 After you've done preparing your wsgi-script, add the following to your httpd.conf. 49 50 {{{ 71 Change it according to the path you installed the Trac libs at. 72 73 == Mapping requests to the script 74 75 After preparing your .wsgi script, add the following to your Apache configuration file, typically `httpd.conf`: 76 77 {{{#!apache 51 78 WSGIScriptAlias /trac /usr/local/trac/mysite/apache/mysite.wsgi 52 79 … … 58 85 }}} 59 86 60 Here, the script is in a subdirectory of the Trac environment. 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 subinterpreters 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. 61 62 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): 63 64 {{{ 87 Here, the script is in a subdirectory of the Trac environment. 88 89 If you followed the directions [TracInstall#cgi-bin Generating the Trac cgi-bin directory], your Apache configuration file should look like following: 90 91 {{{#!apache 92 WSGIScriptAlias /trac /usr/share/trac/cgi-bin/trac.wsgi 93 94 <Directory /usr/share/trac/cgi-bin> 95 WSGIApplicationGroup %{GLOBAL} 96 Order deny,allow 97 Allow from all 98 </Directory> 99 }}} 100 101 In order to let Apache run the script, access to the directory in which the script resides is opened up to all of Apache. Additionally, the `WSGIApplicationGroup` directive ensures that Trac is always run in the first Python interpreter created by mod_wsgi. This is necessary because the Subversion Python bindings, which are used by Trac, don't always work in other sub-interpreters and may cause requests to hang or cause Apache to crash. After adding this configuration, restart Apache, and then it should work. 102 103 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): 104 105 {{{#!python 65 106 def application(environ, start_response): 66 107 start_response('200 OK',[('Content-type','text/html')]) … … 68 109 }}} 69 110 70 See also the mod_wsgi [http://code.google.com/p/modwsgi/wiki/IntegrationWithTrac installation instructions] for Trac. 71 72 For troubleshooting tips, see 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. 111 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. 112 113 == Configuring Authentication 114 115 The following sections describe different methods for setting up authentication. See also [http://httpd.apache.org/docs/2.2/howto/auth.html Authentication, Authorization and Access Control] in the Apache guide. 116 117 === Using Basic Authentication 118 119 The simplest way to enable authentication with Apache is to create a password file. Use the `htpasswd` program as follows: 120 {{{#!sh 121 $ htpasswd -c /somewhere/trac.htpasswd admin 122 New password: <type password> 123 Re-type new password: <type password again> 124 Adding password for user admin 125 }}} 126 127 After the first user, you don't need the "-c" option anymore: 128 {{{#!sh 129 $ htpasswd /somewhere/trac.htpasswd john 130 New password: <type password> 131 Re-type new password: <type password again> 132 Adding password for user john 133 }}} 134 135 ''See the man page for `htpasswd` for full documentation.'' 136 137 After you've created the users, you can set their permissions using TracPermissions. 138 139 Now, you need to enable authentication against the password file in the Apache configuration: 140 {{{#!apache 141 <Location "/trac/login"> 142 AuthType Basic 143 AuthName "Trac" 144 AuthUserFile /somewhere/trac.htpasswd 145 Require valid-user 146 </Location> 147 }}} 148 149 If you are hosting multiple projects, you can use the same password file for all of them: 150 {{{#!apache 151 <LocationMatch "/trac/[^/]+/login"> 152 AuthType Basic 153 AuthName "Trac" 154 AuthUserFile /somewhere/trac.htpasswd 155 Require valid-user 156 </LocationMatch> 157 }}} 158 Note that neither a file nor a directory named 'login' needs to exist.[[BR]] 159 See also the [http://httpd.apache.org/docs/2.2/mod/mod_auth_basic.html mod_auth_basic] documentation. 160 161 === Using Digest Authentication 162 163 For better security, it is recommended that you either enable SSL or at least use the “digest” authentication scheme instead of “Basic”. 164 165 You 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 168 }}} 169 170 The "trac" parameter above is the "realm", and will have to be reused in the Apache configuration in the !AuthName directive: 171 172 {{{#!apache 173 <Location "/trac/login"> 174 AuthType Digest 175 AuthName "trac" 176 AuthDigestDomain /trac 177 AuthUserFile /somewhere/trac.htpasswd 178 Require valid-user 179 </Location> 180 }}} 181 182 For multiple environments, you can use the same `LocationMatch` as described with the previous method. 183 184 '''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. ''' 185 186 Don't forget to activate the mod_auth_digest. For example, on a Debian 4.0r1 (etch) system: 187 {{{#!apache 188 LoadModule auth_digest_module /usr/lib/apache2/modules/mod_auth_digest.so 189 }}} 190 191 See also the [http://httpd.apache.org/docs/2.2/mod/mod_auth_digest.html mod_auth_digest] documentation. 192 193 === Using LDAP Authentication 194 195 Configuration for [http://httpd.apache.org/docs/2.2/mod/mod_ldap.html mod_ldap] authentication in Apache is more involved (httpd 2.2.x and OpenLDAP: slapd 2.3.19). 196 197 1. 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 }}} 202 1. Your httpd.conf also needs to look something like: 203 {{{#!apache 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 192.168.11.0/24 209 AuthType Basic 210 AuthName "Trac" 211 AuthBasicProvider "ldap" 212 AuthLDAPURL "ldap://127.0.0.1/dc=example,dc=co,dc=ke?uid?sub?(objectClass=inetOrgPerson)" 213 authzldapauthoritative Off 214 Require valid-user 215 </Location> 216 }}} 217 1. 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 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 192.168.11.0/24 233 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 242 </Location> 243 }}} 244 245 Note 1: This is the case where the LDAP search will get around the multiple OUs, conecting to the Global Catalog Server portion of AD. Note the port is 3268, not the normal LDAP 389. The GCS is basically a "flattened" tree which allows searching for a user without knowing to which OU they belong. 246 247 Note 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 250 }}} 251 252 See 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. 256 257 === Using SSPI Authentication 258 259 If you are using Apache on Windows, you can use mod_auth_sspi to provide single-sign-on. Download the module from the !SourceForge [http://sourceforge.net/projects/mod-auth-sspi/ mod-auth-sspi project] and then add the following to your !VirtualHost: 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 }}} 273 274 Using the above, usernames in Trac will be of the form `DOMAIN\username`, so you may have to re-add permissions and such. If you do not want the domain to be part of the username, set `SSPIOmitDomain On` instead. 275 276 Some common problems with SSPI authentication: [trac:#1055], [trac:#1168] and [trac:#3338]. 277 278 See also [trac:TracOnWindows/Advanced]. 279 280 === Using Apache authentication with the Account Manager plugin's Login form === 281 282 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]. 283 284 '''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. 285 286 Here is an example (from the !HttpAuthStore link) using acct_mgr-0.4 for hosting a single project: 287 {{{#!ini 288 [components] 289 ; be sure to enable the component 290 acct_mgr.http.HttpAuthStore = enabled 291 292 [account-manager] 293 ; configure the plugin to use a page that is secured with http authentication 294 authentication_url = /authFile 295 password_store = HttpAuthStore 296 }}} 297 This will generally be matched with an Apache config like: 298 {{{#!apache 299 <Location /authFile> 300 …HTTP authentication configuration… 301 Require valid-user 302 </Location> 303 }}} 304 Note that '''authFile''' need not exist (unless you are using Account Manager older than 0.4). See the !HttpAuthStore link above for examples where multiple Trac projects are hosted on a server. 305 306 === Example: Apache/mod_wsgi with Basic Authentication, Trac being at the root of a virtual host 307 308 Per 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. 311 312 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: 313 314 Create the htpasswd file: 315 {{{#!sh 316 cd /home/trac-for-my-proj/the-env 317 htpasswd -c htpasswd firstuser 318 ### and add more users to it as needed: 319 htpasswd htpasswd seconduser 320 }}} 321 Keep the file above your document root for security reasons. 322 323 Create this file e.g. (ubuntu) `/etc/apache2/sites-enabled/trac.my-proj.my-site.org.conf` with the following content: 324 325 {{{#!apache 326 <Directory /home/trac-for-my-proj/the-deploy/cgi-bin/trac.wsgi> 327 WSGIApplicationGroup %{GLOBAL} 328 Order deny,allow 329 Allow from all 330 </Directory> 331 332 <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> 342 </VirtualHost> 343 344 }}} 345 346 Note: for subdomains to work you would probably also need to alter `/etc/hosts` and add A-Records to your host's DNS. 347 348 == Troubleshooting 349 350 === Use a recent version 351 352 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]. 73 353 74 354 ''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 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'' 75 355 76 == Trac with PostgreSQL == 77 78 When using the mod_wsgi adapter with multiple Trac instances and PostgreSQL (or MySQL?) as a database back-end the server can get a lot of open database connections. (and thus PostgreSQL processes) 79 80 A workable solution is to disabled connection pooling in Trac. This is done by setting poolable = False in trac.db.postgres_backend on the PostgreSQLConnection class. 81 82 But it's not necessary to edit the source of trac, the following lines in trac.wsgi will also work: 83 84 {{{ 85 import trac.db.postgres_backend 86 trac.db.postgres_backend.PostgreSQLConnection.poolable = False 87 }}} 88 89 Now Trac drops the connection after serving a page and the connection count on the database will be kept minimal. 90 91 == Getting Trac to work nicely with SSPI and 'Require Group' == 92 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'. 93 94 This WSGI script 'fixes' things, hope it helps: 95 {{{ 356 If you plan to use `mod_wsgi` in embedded mode on Windows or with the MPM worker on Linux, then you will need version 0.3.4 or greater. See [trac:#10675] for details. 357 358 === Getting Trac to work nicely with SSPI and 'Require Group' 359 360 If you have set Trac up on Apache, Win32 and configured SSPI, but added a 'Require group' option to your apache configuration, then the SSPIOmitDomain option is probably not working. If it is not working, your usernames in Trac probably look like 'DOMAIN\user' rather than 'user'. 361 362 This WSGI script 'fixes' that: 363 {{{#!python 96 364 import os 97 365 import trac.web.main … … 105 373 return trac.web.main.dispatch_request(environ, start_response) 106 374 }}} 375 376 === Trac with PostgreSQL 377 378 When using the mod_wsgi adapter with multiple Trac instances and PostgreSQL (or MySQL?) as the database, the server ''may'' create a lot of open database connections and thus PostgreSQL processes. 379 380 A somewhat brutal workaround is to disable connection pooling in Trac. This is done by setting `poolable = False` in `trac.db.postgres_backend` on the `PostgreSQLConnection` class. 381 382 But it is not necessary to edit the source of Trac. The following lines in `trac.wsgi` will also work: 383 384 {{{#!python 385 import trac.db.postgres_backend 386 trac.db.postgres_backend.PostgreSQLConnection.poolable = False 387 }}} 388 389 or 390 391 {{{#!python 392 import trac.db.mysql_backend 393 trac.db.mysql_backend.MySQLConnection.poolable = False 394 }}} 395 396 Now Trac drops the connection after serving a page and the connection count on the database will be kept low. 397 398 //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.// 399 400 === Other resources 401 402 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. 403 107 404 ---- 108 See also: 405 See also: TracGuide, TracInstall, [wiki:TracFastCgi FastCGI], [wiki:TracModPython ModPython], [trac:TracNginxRecipe TracNginxRecipe]