Changes between Initial Version and Version 1 of TracFastCgi


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Timestamp:
Feb 14, 2019, 1:11:02 AM (22 months ago)
Author:
trac
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  • TracFastCgi

    v1 v1  
     1= Trac with FastCGI
     2
     3[[TracGuideToc]]
     4[[PageOutline(2-5, Contents, floated)]]
     5
     6[http://www.fastcgi.com/ FastCGI] interface allows Trac to remain resident much like with [wiki:TracModPython mod_python] or [wiki:TracModWSGI mod_wsgi]. It is faster than external CGI interfaces which must start a new process for each request. Additionally, it is supported by a much wider variety of web servers.
     7
     8Note that unlike mod_python, FastCGI supports [http://httpd.apache.org/docs/suexec.html Apache SuEXEC], ie run with different permissions than the web server runs with. `mod_wsgi` supports the `WSGIDaemonProcess` with user / group parameters to achieve the same effect.
     9
     10'''Note for Windows:''' Trac's FastCGI does not run under Windows, as Windows does not implement `Socket.fromfd`, which is used by `_fcgi.py`. If you want to connect to IIS, you may want to try [trac:TracOnWindowsIisAjp AJP]/[trac:TracOnWindowsIisAjp ISAPI].
     11
     12== Apache configuration
     13
     14There are two FastCGI modules commonly available for Apache: `mod_fastcgi` and `mod_fcgid` (preferred). The latter is more up-to-date.
     15
     16The following sections focus on the FCGI specific setup, see also [wiki:TracModWSGI#ConfiguringAuthentication] for configuring the authentication in Apache.
     17
     18Regardless of which cgi module is used, be sure the web server has executable permissions on the cgi-bin folder. While FastCGI will throw specific permissions errors, mod_fcgid will throw an ambiguous error if this has not been done: `Connection reset by peer: mod_fcgid: error reading data from FastCGI server`.
     19
     20=== Set up with `mod_fastcgi`
     21
     22`mod_fastcgi` uses `FastCgiIpcDir` and `FastCgiConfig` directives that should be added to an appropriate Apache configuration file:
     23{{{#!apache
     24# Enable fastcgi for .fcgi files
     25# (If you're using a distro package for mod_fcgi, something like
     26# this is probably already present)
     27<IfModule mod_fastcgi.c>
     28   AddHandler fastcgi-script .fcgi
     29   FastCgiIpcDir /var/lib/apache2/fastcgi
     30</IfModule>
     31LoadModule fastcgi_module /usr/lib/apache2/modules/mod_fastcgi.so
     32}}}
     33
     34Setting `FastCgiIpcDir` is optional if the default is suitable. Note that the `LoadModule` line must be after the `IfModule` group.
     35
     36Configure `ScriptAlias` or similar options as described in TracCgi, but calling `trac.fcgi` instead of `trac.cgi`.
     37
     38Add the following to the Apache configuration file (below the `FastCgiIpcDir` line) if you intend to set up the `TRAC_ENV` as an overall default:
     39{{{#!apache
     40FastCgiConfig -initial-env TRAC_ENV=/path/to/env/trac
     41}}}
     42
     43Alternatively, you can serve multiple Trac projects in a directory by adding this:
     44{{{#!apache
     45FastCgiConfig -initial-env TRAC_ENV_PARENT_DIR=/parent/dir/of/projects
     46}}}
     47
     48You can also specify the `PYTHON_EGG_CACHE` environment variable using a second `-initial-env` directive:
     49{{{#!apache
     50FastCgiConfig -initial-env TRAC_ENV=/var/lib/trac \
     51    -initial-env PYTHON_EGG_CACHE=/var/lib/trac/plugin-cache
     52}}}
     53
     54=== Set up with `mod_fcgid`
     55
     56Configure `ScriptAlias` (see TracCgi for details), but call `trac.fcgi` instead of `trac.cgi`:
     57{{{#!apache
     58ScriptAlias /trac /path/to/www/trac/cgi-bin/trac.fcgi/
     59}}}
     60
     61Note the slash at the end.
     62
     63To set up Trac environment for `mod_fcgid` it is necessary to use `DefaultInitEnv` directive. It cannot be used in `Directory` or `Location` context, so if you need to support multiple projects, try the alternative environment setup below:
     64{{{#!apache
     65DefaultInitEnv TRAC_ENV /path/to/env/trac/
     66}}}
     67
     68=== Alternative environment setup
     69
     70A better method to specify the path to the Trac environment is to embed the path into `trac.fcgi` script itself. That doesn't require configuration of the server environment variables, works for both [trac:FastCgi] modules as well as for [http://www.lighttpd.net/ lighttpd] and CGI:
     71{{{#!python
     72import os
     73os.environ['TRAC_ENV'] = "/path/to/projectenv"
     74}}}
     75
     76or:
     77{{{#!python
     78import os
     79os.environ['TRAC_ENV_PARENT_DIR'] = "/path/to/project/parent/dir"
     80}}}
     81
     82With this method different projects can be supported by using different `.fcgi` scripts with different `ScriptAliases`.
     83
     84See [https://coderanger.net/~coderanger/httpd/fcgi_example.conf this fcgid example config] which uses a !ScriptAlias directive with trac.fcgi with a trailing / like this:
     85{{{#!apache
     86ScriptAlias / /srv/tracsite/cgi-bin/trac.fcgi/
     87}}}
     88
     89== Cherokee Configuration
     90
     91Configuring [http://cherokee-project.com/ Cherokee] with Trac is straightforward, if you spawn Trac as an SCGI process. You can either start it manually, or better yet, automatically by letting Cherokee spawn the server whenever it is down.
     92
     93First set up an information source in cherokee-admin with a local interpreter:
     94
     95{{{
     96Host:
     97localhost:4433
     98
     99Interpreter:
     100/usr/bin/tracd —single-env —daemonize —protocol=scgi —hostname=localhost —port=4433 /path/to/project/
     101}}}
     102
     103If the port was not reachable, the interpreter command would be launched. Note that, in the definition of the information source, you will have to manually launch the spawner if you use a ''Remote host'' as ''Information source'' instead of a ''Local interpreter''.
     104
     105After doing this, we will just have to create a new rule managed by the SCGI handler to access Trac. It can be created in a new virtual server, trac.example.net for instance, and will only need two rules. The '''default''' one will use the SCGI handler associated to the previously created information source.
     106The second rule will be there to serve the few static files needed to correctly display the Trac interface. Create it as ''Directory rule'' for ''/common'' and just set it to the ''Static files'' handler and with a ''Document root'' that points to the appropriate files: ''$TRAC_LOCAL/htdocs/'' (where $TRAC_LOCAL is a directory defined by the user or the system administrator to place local Trac resources).
     107
     108'''Note:''' If the tracd process fails to start up, and Cherokee displays a 503 error page, you might be missing the [http://trac.saddi.com/flup python-flup] package ([trac:#9903]). Python-flup is a dependency which provides Trac with SCGI capability. You can install it on Debian based systems with:
     109{{{#!sh
     110sudo apt-get install python-flup
     111}}}
     112
     113== Lighttpd Configuration
     114
     115The FastCGI front-end was developed primarily for use with alternative webservers, such as [http://www.lighttpd.net/ Lighttpd].
     116
     117Lighttpd is a secure, fast, compliant and very flexible web-server that has been optimized for high-performance environments. It has a very low memory footprint compared to other web servers and takes care of CPU load.
     118
     119For using `trac.fcgi`(prior to 0.11) / fcgi_frontend.py (0.11) with Lighttpd add the following to your lighttpd.conf:
     120{{{
     121#var.fcgi_binary="/usr/bin/python /path/to/fcgi_frontend.py" # 0.11 if installed with easy_setup, it is inside the egg directory
     122var.fcgi_binary="/path/to/cgi-bin/trac.fcgi" # 0.10 name of prior fcgi executable
     123fastcgi.server = ("/trac" =>
     124   
     125                   ("trac" =>
     126                     ("socket" => "/tmp/trac-fastcgi.sock",
     127                      "bin-path" => fcgi_binary,
     128                      "check-local" => "disable",
     129                      "bin-environment" =>
     130                        ("TRAC_ENV" => "/path/to/projenv")
     131                     )
     132                   )
     133                 )
     134}}}
     135
     136Note that you will need to add a new entry to `fastcgi.server` for each separate Trac instance that you wish to run. Alternatively, you may use the `TRAC_ENV_PARENT_DIR` variable instead of `TRAC_ENV` as described above, and you may set one of the two in `trac.fcgi` instead of in `lighttpd.conf` using `bin-environment`, as in the section above on Apache configuration.
     137
     138Note that Lighttpd has a bug related to 'SCRIPT_NAME' and 'PATH_INFO' when the uri of fastcgi.server is '/' instead of '/trac' in this example (see [trac:#2418]). This is fixed in Lighttpd 1.5, and under Lighttpd 1.4.23 or later the workaround is to add `"fix-root-scriptname" => "enable"` as a parameter of fastcgi.server.
     139
     140For using two projects with lighttpd add the following to your `lighttpd.conf`:
     141{{{
     142fastcgi.server = ("/first" =>
     143                   ("first" =>
     144                    ("socket" => "/tmp/trac-fastcgi-first.sock",
     145                     "bin-path" => fcgi_binary,
     146                     "check-local" => "disable",
     147                     "bin-environment" =>
     148                       ("TRAC_ENV" => "/path/to/projenv-first")
     149                    )
     150                  ),
     151                  "/second" =>
     152                    ("second" =>
     153                    ("socket" => "/tmp/trac-fastcgi-second.sock",
     154                     "bin-path" => fcgi_binary,
     155                     "check-local" => "disable",
     156                     "bin-environment" =>
     157                       ("TRAC_ENV" => "/path/to/projenv-second")
     158                    )
     159                  )
     160                )
     161}}}
     162
     163Note that the field values are different. If you prefer setting the environment variables in the `.fcgi` scripts, then copy/rename `trac.fcgi`, eg to `first.fcgi` and `second.fcgi`, and reference them in the above settings.
     164Note that the above will result in different processes in any event, even if both are running from the same `trac.fcgi` script.
     165
     166{{{#!div class=important
     167'''Note:''' The order in which the server.modules are loaded is very important: if mod_auth is not loaded '''before''' mod_fastcgi, then the server will fail to authenticate the user.
     168}}}
     169
     170For authentication you should enable mod_auth in lighttpd.conf 'server.modules', select auth.backend and auth rules:
     171{{{
     172server.modules              = (
     173...
     174  "mod_auth",
     175...
     176)
     177
     178auth.backend               = "htpasswd"
     179
     180# Separated password files for each project
     181# See "Conditional Configuration" in
     182# http://trac.lighttpd.net/trac/file/branches/lighttpd-merge-1.4.x/doc/configuration.txt
     183
     184$HTTP["url"] =~ "^/first/" {
     185  auth.backend.htpasswd.userfile = "/path/to/projenv-first/htpasswd.htaccess"
     186}
     187$HTTP["url"] =~ "^/second/" {
     188  auth.backend.htpasswd.userfile = "/path/to/projenv-second/htpasswd.htaccess"
     189}
     190
     191# Enable auth on trac URLs, see
     192# http://trac.lighttpd.net/trac/file/branches/lighttpd-merge-1.4.x/doc/authentication.txt
     193
     194auth.require = ("/first/login" =>
     195                ("method"  => "basic",
     196                 "realm"   => "First project",
     197                 "require" => "valid-user"
     198                ),
     199                "/second/login" =>
     200                ("method"  => "basic",
     201                 "realm"   => "Second project",
     202                 "require" => "valid-user"
     203                )
     204               )
     205
     206}}}
     207
     208Note that Lighttpd (v1.4.3) stops if the password file doesn't exist.
     209
     210Note that Lighttpd doesn't support 'valid-user' in versions prior to 1.3.16.
     211
     212Conditional configuration is also useful for mapping static resources, ie serving out images and CSS directly instead of through FastCGI:
     213{{{
     214# Aliasing functionality is needed
     215server.modules += ("mod_alias")
     216
     217# Set up an alias for the static resources
     218alias.url = ("/trac/chrome/common" => "/usr/share/trac/htdocs")
     219
     220# Use negative lookahead, matching all requests that ask for any resource under /trac, EXCEPT in
     221# /trac/chrome/common, and use FastCGI for those
     222$HTTP["url"] =~ "^/trac(?!/chrome/common)" {
     223# Even if you have other fastcgi.server declarations for applications other than Trac, do NOT use += here
     224fastcgi.server = ("/trac" =>
     225                   ("trac" =>
     226                     ("socket" => "/tmp/trac-fastcgi.sock",
     227                      "bin-path" => fcgi_binary,
     228                      "check-local" => "disable",
     229                      "bin-environment" =>
     230                        ("TRAC_ENV" => "/path/to/projenv")
     231                     )
     232                   )
     233                 )
     234}
     235}}}
     236
     237The technique can be easily adapted for use with multiple projects by creating aliases for each of them, and wrapping the fastcgi.server declarations inside conditional configuration blocks.
     238
     239Also there is another way to handle multiple projects and it uses `TRAC_ENV_PARENT_DIR` instead of `TRAC_ENV` as well as global authentication:
     240{{{
     241#  This is for handling multiple projects
     242  alias.url       = ( "/trac/" => "/path/to/trac/htdocs/" )
     243
     244  fastcgi.server += ("/projects"  =>
     245                      ("trac" =>
     246                        (
     247                          "socket" => "/tmp/trac.sock",
     248                          "bin-path" => fcgi_binary,
     249                          "check-local" => "disable",
     250                          "bin-environment" =>
     251                            ("TRAC_ENV_PARENT_DIR" => "/path/to/parent/dir/of/projects/" )
     252                        )
     253                      )
     254                    )
     255#And here starts the global auth configuration
     256  auth.backend = "htpasswd"
     257  auth.backend.htpasswd.userfile = "/path/to/unique/htpassword/file/trac.htpasswd"
     258  $HTTP["url"] =~ "^/projects/.*/login$" {
     259    auth.require = ("/" =>
     260                     (
     261                       "method"  => "basic",
     262                       "realm"   => "trac",
     263                       "require" => "valid-user"
     264                     )
     265                   )
     266  }
     267}}}
     268
     269Changing date/time format also supported by lighttpd over environment variable LC_TIME:
     270{{{
     271fastcgi.server = ("/trac" =>
     272                   ("trac" =>
     273                     ("socket" => "/tmp/trac-fastcgi.sock",
     274                      "bin-path" => fcgi_binary,
     275                      "check-local" => "disable",
     276                      "bin-environment" =>
     277                        ("TRAC_ENV" => "/path/to/projenv",
     278                        "LC_TIME" => "ru_RU")
     279                     )
     280                   )
     281                 )
     282}}}
     283
     284For details about languages specification see [trac:TracFaq TracFaq] question 2.13.
     285
     286Other important information like the [wiki:TracInstall#MappingStaticResources mapping static resources advices] are useful for non-fastcgi specific installation aspects.
     287
     288Relaunch Lighttpd and browse to `http://yourhost.example.org/trac` to access Trac.
     289
     290Note about running Lighttpd with reduced permissions: If nothing else helps and trac.fcgi doesn't start with Lighttpd settings `server.username = "www-data"`, `server.groupname = "www-data"`, then in the `bin-environment` section set `PYTHON_EGG_CACHE` to the home directory of `www-data` or some other directory accessible to this account for writing.
     291
     292== !LiteSpeed Configuration
     293
     294The FastCGI front-end was developed primarily for use with alternative webservers, such as [http://www.litespeedtech.com/ LiteSpeed].
     295
     296!LiteSpeed web server is an event-driven asynchronous Apache replacement designed from the ground-up to be secure, scalable, and operate with minimal resources. !LiteSpeed can operate directly from an Apache config file and is targeted for business-critical environments.
     297
     298 1. Please make sure you have a working install of a Trac project. Test install with "tracd" first.
     299 1. Create a Virtual Host for this setup. From now on we will refer to this vhost as !TracVhost. For this tutorial we will be assuming that your Trac project will be accessible via:
     300{{{
     301http://yourdomain.com/trac/
     302}}}
     303 1. Go "!TracVhost → External Apps" tab and create a new "External Application":
     304{{{
     305Name: MyTracFCGI       
     306Address: uds://tmp/lshttpd/mytracfcgi.sock
     307Max Connections: 10
     308Environment: TRAC_ENV=/fullpathto/mytracproject/ <--- path to root folder of trac project
     309Initial Request Timeout (secs): 30
     310Retry Timeout (secs): 0
     311Persistent Connection   Yes
     312Connection Keepalive Timeout: 30
     313Response Bufferring: No
     314Auto Start: Yes
     315Command: /usr/share/trac/cgi-bin/trac.fcgi  <--- path to trac.fcgi
     316Back Log: 50
     317Instances: 10
     318}}}
     319 1. Optional: If you need to use htpasswd based authentication. Go to "!TracVhost → Security" tab and create a new security Realm:
     320 {{{
     321DB Type: Password File
     322Realm Name: MyTracUserDB               <--- any name you wish and referenced later
     323User DB Location: /fullpathto/htpasswd <--- path to your htpasswd file
     324}}}
     325 If you don’t have a htpasswd file or don’t know how to create the entries within one, go to http://sherylcanter.com/encrypt.php, to generate the user:password combos.
     326 1. Go to "!PythonVhost → Contexts" and create a new FCGI Context:
     327 {{{
     328URI: /trac/                              <--- URI path to bind to python fcgi app we created   
     329Fast CGI App: [VHost Level] MyTractFCGI  <--- select the Trac fcgi extapp we just created
     330Realm: TracUserDB                        <--- only if (4) is set. select realm created in (4)
     331}}}
     332 1. Modify `/fullpathto/mytracproject/conf/trac.ini`:
     333 {{{
     334#find/set base_rul, url, and link variables
     335base_url = http://yourdomain.com/trac/ <--- base url to generate correct links to
     336url = http://yourdomain.com/trac/      <--- link of project
     337link = http://yourdomain.com/trac/     <--- link of graphic logo
     338}}}
     339 1. Restart !LiteSpeed: `lswsctrl restart`, and access your new Trac project at {{{http://yourdomain.com/trac/}}}.
     340
     341== Nginx Configuration
     342
     343[http://nginx.org/en/ Nginx] is able to communicate with FastCGI processes, but can not spawn them. So you need to start FastCGI server for Trac separately.
     344
     345 1. Nginx configuration with basic authentication handled by Nginx - confirmed to work on 0.6.32
     346 {{{#!nginx
     347    server {
     348        listen       10.9.8.7:443;
     349        server_name  trac.example;
     350
     351        ssl                  on;
     352        ssl_certificate      /etc/ssl/trac.example.crt;
     353        ssl_certificate_key  /etc/ssl/trac.example.key;
     354
     355        ssl_session_timeout  5m;
     356
     357        ssl_protocols  SSLv2 SSLv3 TLSv1;
     358        ssl_ciphers  ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP;
     359        ssl_prefer_server_ciphers   on;
     360
     361        # it makes sense to serve static resources through Nginx (or ``~ [/some/prefix]/chrome/(.*)``)
     362        location ~ /chrome/(.*) {
     363             alias /home/trac/instance/static/htdocs/$1;
     364        }
     365
     366        # You can copy this whole location to ``location [/some/prefix](/login)``
     367        # and remove the auth entries below if you want Trac to enforce
     368        # authorization where appropriate instead of needing to authenticate
     369        # for accessing the whole site.
     370        # (Or ``~ location /some/prefix(/.*)``.)
     371        location ~ (/.*) {
     372            auth_basic            "trac realm";
     373            auth_basic_user_file /home/trac/htpasswd;
     374
     375            # socket address
     376            fastcgi_pass   unix:/home/trac/run/instance.sock;
     377
     378            # python - wsgi specific
     379            fastcgi_param HTTPS on;
     380
     381            ## WSGI REQUIRED VARIABLES
     382            # WSGI application name - trac instance prefix.
     383            # (Or ``fastcgi_param  SCRIPT_NAME  /some/prefix``.)
     384            fastcgi_param  SCRIPT_NAME        "";
     385            fastcgi_param  PATH_INFO          $1;
     386
     387            ## WSGI NEEDED VARIABLES - trac warns about them
     388            fastcgi_param  REQUEST_METHOD     $request_method;
     389            fastcgi_param  SERVER_NAME        $server_name;
     390            fastcgi_param  SERVER_PORT        $server_port;
     391            fastcgi_param  SERVER_PROTOCOL    $server_protocol;
     392            fastcgi_param  QUERY_STRING       $query_string;
     393
     394            # For Nginx authentication to work - do not forget to comment these
     395            # lines if not using Nginx for authentication
     396            fastcgi_param  AUTH_USER          $remote_user;
     397            fastcgi_param  REMOTE_USER        $remote_user;
     398
     399            # for ip to work
     400            fastcgi_param REMOTE_ADDR         $remote_addr;
     401
     402            # For attchments to work
     403            fastcgi_param    CONTENT_TYPE     $content_type;
     404            fastcgi_param    CONTENT_LENGTH   $content_length;
     405        }
     406    }
     407}}}
     408 1. Modified trac.fcgi:
     409 {{{#!python
     410#!/usr/bin/env python
     411import os
     412sockaddr = '/home/trac/run/instance.sock'
     413os.environ['TRAC_ENV'] = '/home/trac/instance'
     414
     415try:
     416     from trac.web.main import dispatch_request
     417     import trac.web._fcgi
     418
     419     fcgiserv = trac.web._fcgi.WSGIServer(dispatch_request,
     420          bindAddress = sockaddr, umask = 7)
     421     fcgiserv.run()
     422
     423except SystemExit:
     424    raise
     425except Exception, e:
     426    print 'Content-Type: text/plain\r\n\r\n',
     427    print 'Oops...'
     428    print
     429    print 'Trac detected an internal error:'
     430    print
     431    print e
     432    print
     433    import traceback
     434    import StringIO
     435    tb = StringIO.StringIO()
     436    traceback.print_exc(file=tb)
     437    print tb.getvalue()
     438
     439}}}
     440 1. Reload nginx and launch trac.fcgi:
     441 {{{#!sh
     442trac@trac.example ~ $ ./trac-standalone-fcgi.py
     443}}}
     444
     445The above assumes that:
     446 * There is a user named 'trac' for running Trac instances and keeping Trac environments in its home directory
     447 * `/home/trac/instance` contains a Trac environment
     448 * `/home/trac/htpasswd` contains authentication information
     449 * `/home/trac/run` is owned by the same group the Nginx runs under
     450  * and if your system is Linux the `/home/trac/run` has setgid bit set (`chmod g+s run`)
     451  * and patch from [trac:#7239] is applied, or you'll have to fix the socket file permissions every time
     452
     453Unfortunately Nginx does not support variable expansion in fastcgi_pass directive.
     454Thus it is not possible to serve multiple Trac instances from one server block.
     455
     456If you worry enough about security, run Trac instances under separate users.
     457
     458Another way to run Trac as a FCGI external application is offered in [trac:#6224].
     459
     460----
     461See also: TracGuide, TracInstall, [wiki:TracModWSGI ModWSGI], [wiki:TracCgi CGI], [wiki:TracModPython ModPython], [trac:TracNginxRecipe TracNginxRecipe]