Changes between Version 1 and Version 2 of Trac Fast Cgi


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Timestamp:
02/06/14 20:46:04 (4 years ago)
Author:
trac
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  • Trac Fast Cgi

    v1 v2  
     1[[PageOutline]] 
     2 
    13= Trac with FastCGI = 
    24 
    3 Since version 0.9, Trac supports being run through the [http://www.fastcgi.com/ FastCGI] interface. Like [wiki:TracModPython mod_python], this allows Trac to remain resident, and is faster than external CGI interfaces which must start a new process for each request. However, unlike mod_python, it is able to support [http://httpd.apache.org/docs/suexec.html SuEXEC]. Additionally, it is supported by much wider variety of web servers. 
     5[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 much wider variety of web servers. 
     6 
     7Note that unlike mod_python, FastCGI supports [http://httpd.apache.org/docs/suexec.html Apache SuEXEC], i.e. run with different permissions than web server running with (`mod_wsgi` supports the `WSGIDaemonProcess` with user / group parameters to achieve the same effect). 
     8 
     9'''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]. 
     10 
     11[[PageOutline(2-3,Overview,inline)]] 
     12 
    413 
    514== Simple Apache configuration == 
    615 
    716There are two FastCGI modules commonly available for Apache: `mod_fastcgi` and 
    8 `mod_fcgid`.  The `FastCgiIpcDir` and `FastCgiConfig` directives discussed 
    9 below are `mod_fastcgi` directives; the `DefaultInitEnv` is a `mod_fgcid` 
    10 directive. 
    11  
    12 For `mod_fastcgi`, add the following to an appropriate Apache configuration 
    13 file: 
     17`mod_fcgid` (preferred). The latter is more up-to-date. 
     18 
     19The following sections focus on the FCGI specific setup, see also [wiki:TracModWSGI#ConfiguringAuthentication] for configuring the authentication in Apache. 
     20 
     21Regardless 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)  
     22 
     23=== Set up with `mod_fastcgi` === 
     24`mod_fastcgi` uses `FastCgiIpcDir` and `FastCgiConfig` directives that should be added to an appropriate Apache configuration file: 
    1425{{{ 
    1526# Enable fastcgi for .fcgi files 
     
    2738calling `trac.fcgi` instead of `trac.cgi`. 
    2839 
    29 You can set up the `TRAC_ENV` as an overall default: 
     40Add the following to the Apache configuration file (below the `FastCgiIpcDir` line) if you intend to set up the `TRAC_ENV` as an overall default: 
    3041{{{ 
    3142FastCgiConfig -initial-env TRAC_ENV=/path/to/env/trac 
    3243}}} 
    3344 
    34 Or you can serve multiple Trac projects in a directory like: 
     45Alternatively, you can serve multiple Trac projects in a directory by adding this: 
    3546{{{ 
    3647FastCgiConfig -initial-env TRAC_ENV_PARENT_DIR=/parent/dir/of/projects 
    3748}}} 
    3849 
    39 But neither of these will work for `mod_fcgid`.  A similar but partial 
    40 solution for `mod_fcgid` is: 
     50=== Set up with `mod_fcgid` === 
     51Configure `ScriptAlias` (see TracCgi for details), but call `trac.fcgi` 
     52instead of `trac.cgi`. Note that slash at the end - it is important. 
     53{{{ 
     54ScriptAlias /trac /path/to/www/trac/cgi-bin/trac.fcgi/ 
     55}}} 
     56 
     57To set up Trac environment for `mod_fcgid` it is necessary to use 
     58`DefaultInitEnv` directive. It cannot be used in `Directory` or 
     59`Location` context, so if you need to support multiple projects, try 
     60alternative environment setup below. 
     61 
    4162{{{ 
    4263DefaultInitEnv TRAC_ENV /path/to/env/trac/ 
    4364}}} 
    44 But this cannot be used in `Directory` or `Location` context, which makes it 
    45 difficult to support multiple projects. 
    46  
    47 A better method which works for both of these modules (and for  [http://www.lighttpd.net/ lighttpd] and CGI as well), because it involves 
    48 no server configuration settings for environment variables, is to set one 
    49 of the variables in `trac.fcgi`, e.g.: 
     65 
     66=== alternative environment setup === 
     67A better method to specify path to Trac environment is to embed the path 
     68into `trac.fcgi` script itself. That doesn't require configuration of server 
     69environment variables, works for both FastCgi modules 
     70(and for [http://www.lighttpd.net/ lighttpd] and CGI as well): 
    5071{{{ 
    5172import os 
     
    5879}}} 
    5980 
    60 Using this method, different projects can be supported by using different 
    61 `.fcgi` scripts with different `ScriptAliases`, copying and appropriately 
    62 renaming `trac.fcgi` and adding the above code to create each such script. 
     81With this method different projects can be supported by using different 
     82`.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{{{ 
     86ScriptAlias / /srv/tracsite/cgi-bin/trac.fcgi/ 
     87}}} 
     88 
     89== Simple Cherokee Configuration == 
     90 
     91The configuration on Cherokee's side is quite simple. You will only need to know that you can spawn Trac as an SCGI process. 
     92You can either start it manually, or better yet, automatically by letting Cherokee spawn the server whenever it is down. 
     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 
     108Note:\\ 
     109If 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.\\ 
     110Python-flup is a dependency which provides trac with SCGI capability. You can install it on debian based systems with: 
     111{{{ 
     112sudo apt-get install python-flup 
     113}}} 
     114 
    63115 
    64116== Simple Lighttpd Configuration == 
     
    69121environments.  It has a very low memory footprint compared to other web servers and takes care of CPU load. 
    70122 
    71 For using `trac.fcgi` with lighttpd add the following to your lighttpd.conf: 
    72 {{{ 
     123For using `trac.fcgi`(prior to 0.11) / fcgi_frontend.py (0.11) with lighttpd add the following to your lighttpd.conf: 
     124{{{ 
     125#var.fcgi_binary="/usr/bin/python /path/to/fcgi_frontend.py" # 0.11 if installed with easy_setup, it is inside the egg directory 
     126var.fcgi_binary="/path/to/cgi-bin/trac.fcgi" # 0.10 name of prior fcgi executable 
    73127fastcgi.server = ("/trac" => 
     128    
    74129                   ("trac" => 
    75130                     ("socket" => "/tmp/trac-fastcgi.sock", 
    76                       "bin-path" => "/path/to/cgi-bin/trac.fcgi", 
     131                      "bin-path" => fcgi_binary, 
    77132                      "check-local" => "disable", 
    78133                      "bin-environment" => 
     
    87142using `bin-environment` (as in the section above on Apache configuration). 
    88143 
     144Note 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. 
     145 
    89146For using two projects with lighttpd add the following to your `lighttpd.conf`: 
    90147{{{ 
     
    92149                   ("first" => 
    93150                    ("socket" => "/tmp/trac-fastcgi-first.sock", 
    94                      "bin-path" => "/path/to/cgi-bin/trac.fcgi", 
     151                     "bin-path" => fcgi_binary, 
    95152                     "check-local" => "disable", 
    96153                     "bin-environment" => 
     
    101158                    ("second" => 
    102159                    ("socket" => "/tmp/trac-fastcgi-second.sock", 
    103                      "bin-path" => "/path/to/cgi-bin/trac.fcgi", 
     160                     "bin-path" => fcgi_binary, 
    104161                     "check-local" => "disable", 
    105162                     "bin-environment" => 
     
    114171Note that the above will result in different processes in any event, even 
    115172if both are running from the same `trac.fcgi` script. 
    116 {{{ 
    117 #!html 
    118 <p style="background: #fdc; border: 2px solid #d00; font-style: italic; padding: 0 .5em; margin: 1em 0;"> 
    119 <strong>Note from c00i90wn:</strong> It's very important the order on which server.modules are loaded, if mod_auth is not loaded <strong>BEFORE</strong> mod_fastcgi, then the server will fail to authenticate the user. 
    120 </p> 
    121 }}} 
     173 
     174{{{ 
     175#!div class=important 
     176'''Note''' It's very important the order on which server.modules are loaded, if mod_auth is not loaded '''BEFORE''' mod_fastcgi, then the server will fail to authenticate the user. 
     177}}} 
     178 
    122179For authentication you should enable mod_auth in lighttpd.conf 'server.modules', select auth.backend and auth rules: 
    123180{{{ 
     
    167224server.modules += ("mod_alias") 
    168225 
    169 # Setup an alias for the static resources 
     226# Set up an alias for the static resources 
    170227alias.url = ("/trac/chrome/common" => "/usr/share/trac/htdocs") 
    171228 
     
    177234                   ("trac" => 
    178235                     ("socket" => "/tmp/trac-fastcgi.sock", 
    179                       "bin-path" => "/path/to/cgi-bin/trac.fcgi", 
     236                      "bin-path" => fcgi_binary, 
    180237                      "check-local" => "disable", 
    181238                      "bin-environment" => 
     
    196253                        ( 
    197254                          "socket" => "/tmp/trac.sock", 
    198                           "bin-path" => "/path/to/cgi-bin/trac.fcgi", 
     255                          "bin-path" => fcgi_binary, 
    199256                          "check-local" => "disable", 
    200257                          "bin-environment" => 
     
    222279                   ("trac" => 
    223280                     ("socket" => "/tmp/trac-fastcgi.sock", 
    224                       "bin-path" => "/path/to/cgi-bin/trac.fcgi", 
     281                      "bin-path" => fcgi_binary, 
    225282                      "check-local" => "disable", 
    226283                      "bin-environment" => 
     
    231288                 ) 
    232289}}} 
    233 For details about languages specification see TracFaq question 2.13. 
    234  
    235 Other important information like [http://trac.lighttpd.net/trac/wiki/TracInstall this updated TracInstall page], [wiki:TracCgi#MappingStaticResources and this] are useful for non-fastcgi specific installation aspects. 
    236  
    237 If you use trac-0.9, read [http://lists.edgewall.com/archive/trac/2005-November/005311.html about small bug] 
     290For details about languages specification see [trac:TracFaq TracFaq] question 2.13. 
     291 
     292Other important information like the [wiki:TracInstall#MappingStaticResources mapping static resources advices] are useful for non-fastcgi specific installation aspects. 
     293] 
    238294 
    239295Relaunch lighttpd, and browse to `http://yourhost.example.org/trac` to access Trac. 
     
    241297Note about running lighttpd with reduced permissions: 
    242298 
    243   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. 
    244  
    245  
    246 == Simple LiteSpeed Configuration == 
     299If 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. 
     300 
     301 
     302== Simple !LiteSpeed Configuration == 
    247303 
    248304The FastCGI front-end was developed primarily for use with alternative webservers, such as [http://www.litespeedtech.com/ LiteSpeed]. 
    249305 
    250 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. 
    251  
    252 Setup 
    253  
    254 1) Please make sure you have first have a working install of a Trac project. Test install with “tracd” first. 
    255  
    256 2) 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: 
     306!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. 
     307 
     308 1. Please make sure you have first have a working install of a Trac project. Test install with “tracd” first. 
     309 
     310 2. 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: 
    257311 
    258312{{{ 
     
    260314}}} 
    261315 
    262 3) Go “TracVhost → External Apps” tab and create a new “External Application”. 
     316 3. Go “!TracVhost → External Apps” tab and create a new “External Application”. 
    263317 
    264318{{{ 
     
    278332}}} 
    279333 
    280 4) Optional. If you need to use htpasswd based authentication. Go to “TracVhost → Security” tab and create a new security “Realm”. 
     334 4. Optional. If you need to use htpasswd based authentication. Go to “!TracVhost → Security” tab and create a new security “Realm”. 
    281335 
    282336{{{ 
     
    288342If 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. 
    289343 
    290 5) Go to “PythonVhost → Contexts” and create a new “FCGI Context”. 
     344 5. Go to “!PythonVhost → Contexts” and create a new “FCGI Context”. 
    291345 
    292346{{{ 
    293347URI: /trac/                              <--- URI path to bind to python fcgi app we created     
    294348Fast CGI App: [VHost Level] MyTractFCGI  <--- select the trac fcgi extapp we just created 
    295 Realm: TracUserDB                        <--- only if (4) is set. select ream created in (4) 
    296 }}} 
    297  
    298 6) Modify /fullpathto/mytracproject/conf/trac.ini 
     349Realm: TracUserDB                        <--- only if (4) is set. select realm created in (4) 
     350}}} 
     351 
     352 6. Modify `/fullpathto/mytracproject/conf/trac.ini` 
    299353 
    300354{{{ 
     
    305359}}} 
    306360 
    307 7) Restart LiteSpeed, “lswsctrl restart”, and access your new Trac project at:  
     361 7. Restart !LiteSpeed, “lswsctrl restart”, and access your new Trac project at:  
    308362 
    309363{{{ 
     
    311365}}} 
    312366 
     367 
     368== Simple Nginx Configuration == 
     369 
     370Nginx is able to communicate with FastCGI processes, but can not spawn them. So you need to start FastCGI server for Trac separately. 
     371 
     372 1. Nginx configuration with basic authentication handled by Nginx - confirmed to work on 0.6.32 
     373{{{ 
     374    server { 
     375        listen       10.9.8.7:443; 
     376        server_name  trac.example; 
     377 
     378        ssl                  on; 
     379        ssl_certificate      /etc/ssl/trac.example.crt; 
     380        ssl_certificate_key  /etc/ssl/trac.example.key; 
     381 
     382        ssl_session_timeout  5m; 
     383 
     384        ssl_protocols  SSLv2 SSLv3 TLSv1; 
     385        ssl_ciphers  ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP; 
     386        ssl_prefer_server_ciphers   on; 
     387 
     388        # (Or ``^/some/prefix/(.*)``. 
     389        if ($uri ~ ^/(.*)) { 
     390             set $path_info /$1; 
     391        } 
     392 
     393        # it makes sense to serve static resources through Nginx 
     394        location /chrome/ { 
     395             alias /home/trac/instance/static/htdocs/; 
     396        } 
     397 
     398        # You can copy this whole location to ``location [/some/prefix]/login`` 
     399        # and remove the auth entries below if you want Trac to enforce 
     400        # authorization where appropriate instead of needing to authenticate 
     401        # for accessing the whole site. 
     402        # (Or ``location /some/prefix``.) 
     403        location / { 
     404            auth_basic            "trac realm"; 
     405            auth_basic_user_file /home/trac/htpasswd; 
     406 
     407            # socket address 
     408            fastcgi_pass   unix:/home/trac/run/instance.sock; 
     409 
     410            # python - wsgi specific 
     411            fastcgi_param HTTPS on; 
     412 
     413            ## WSGI REQUIRED VARIABLES 
     414            # WSGI application name - trac instance prefix. 
     415            # (Or ``fastcgi_param  SCRIPT_NAME  /some/prefix``.) 
     416            fastcgi_param  SCRIPT_NAME        ""; 
     417            fastcgi_param  PATH_INFO          $path_info; 
     418 
     419            ## WSGI NEEDED VARIABLES - trac warns about them 
     420            fastcgi_param  REQUEST_METHOD     $request_method; 
     421            fastcgi_param  SERVER_NAME        $server_name; 
     422            fastcgi_param  SERVER_PORT        $server_port; 
     423            fastcgi_param  SERVER_PROTOCOL    $server_protocol; 
     424            fastcgi_param  QUERY_STRING       $query_string; 
     425 
     426            # For Nginx authentication to work - do not forget to comment these 
     427            # lines if not using Nginx for authentication 
     428            fastcgi_param  AUTH_USER          $remote_user; 
     429            fastcgi_param  REMOTE_USER        $remote_user; 
     430 
     431            # for ip to work 
     432            fastcgi_param REMOTE_ADDR         $remote_addr; 
     433 
     434            # For attchments to work 
     435            fastcgi_param    CONTENT_TYPE     $content_type; 
     436            fastcgi_param    CONTENT_LENGTH   $content_length; 
     437        } 
     438    } 
     439}}} 
     440 
     441 2. Modified trac.fcgi: 
     442 
     443{{{ 
     444#!/usr/bin/env python 
     445import os 
     446sockaddr = '/home/trac/run/instance.sock' 
     447os.environ['TRAC_ENV'] = '/home/trac/instance' 
     448 
     449try: 
     450     from trac.web.main import dispatch_request 
     451     import trac.web._fcgi 
     452 
     453     fcgiserv = trac.web._fcgi.WSGIServer(dispatch_request,  
     454          bindAddress = sockaddr, umask = 7) 
     455     fcgiserv.run() 
     456 
     457except SystemExit: 
     458    raise 
     459except Exception, e: 
     460    print 'Content-Type: text/plain\r\n\r\n', 
     461    print 'Oops...' 
     462    print 
     463    print 'Trac detected an internal error:' 
     464    print 
     465    print e 
     466    print 
     467    import traceback 
     468    import StringIO 
     469    tb = StringIO.StringIO() 
     470    traceback.print_exc(file=tb) 
     471    print tb.getvalue() 
     472 
     473}}} 
     474 
     475 3. reload nginx and launch trac.fcgi like that: 
     476 
     477{{{ 
     478trac@trac.example ~ $ ./trac-standalone-fcgi.py  
     479}}} 
     480 
     481The above assumes that: 
     482 * There is a user named 'trac' for running trac instances and keeping trac environments in its home directory. 
     483 * `/home/trac/instance` contains a trac environment 
     484 * `/home/trac/htpasswd` contains authentication information 
     485 * `/home/trac/run` is owned by the same group the nginx runs under 
     486  * and if your system is Linux the `/home/trac/run` has setgid bit set (`chmod g+s run`) 
     487  * and patch from ticket #T7239 is applied, or you'll have to fix the socket file permissions every time 
     488 
     489Unfortunately nginx does not support variable expansion in fastcgi_pass directive.  
     490Thus it is not possible to serve multiple trac instances from one server block.  
     491 
     492If you worry enough about security, run trac instances under separate users.  
     493 
     494Another way to run trac as a FCGI external application is offered in ticket #T6224 
     495 
    313496---- 
    314 See also TracCgi, TracModPython, TracInstall, TracGuide 
     497See also:  TracGuide, TracInstall, [wiki:TracModWSGI ModWSGI], [wiki:TracCgi CGI], [wiki:TracModPython ModPython], [trac:TracNginxRecipe TracNginxRecipe]