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# Changes between Version 3 and Version 4 of TracFastCgi

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Jul 17, 2018, 3:10:47 PM (23 months ago)
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 v3 [[PageOutline]] = Trac with FastCGI = [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. Note 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). = Trac with FastCGI [[TracGuideToc]] [[PageOutline(2-5, Contents, floated)]] [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. Note 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. '''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]. [[PageOutline(2-3,Overview,inline)]] == Simple Apache configuration == There are two FastCGI modules commonly available for Apache: mod_fastcgi and mod_fcgid (preferred). The latter is more up-to-date. == Apache configuration There are two FastCGI modules commonly available for Apache: mod_fastcgi and mod_fcgid (preferred). The latter is more up-to-date. The following sections focus on the FCGI specific setup, see also [wiki:TracModWSGI#ConfiguringAuthentication] for configuring the authentication in Apache. Regardless 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) === Set up with mod_fastcgi === Regardless 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. === Set up with mod_fastcgi mod_fastcgi uses FastCgiIpcDir and FastCgiConfig directives that should be added to an appropriate Apache configuration file: {{{ {{{#!apache # Enable fastcgi for .fcgi files # (If you're using a distro package for mod_fcgi, something like LoadModule fastcgi_module /usr/lib/apache2/modules/mod_fastcgi.so }}} Setting FastCgiIpcDir is optional if the default is suitable. Note that the LoadModule line must be after the IfModule group. Configure ScriptAlias or similar options as described in TracCgi, but calling trac.fcgi instead of trac.cgi. Configure ScriptAlias or similar options as described in TracCgi, but calling trac.fcgi instead of trac.cgi. Add the following to the Apache configuration file (below the FastCgiIpcDir line) if you intend to set up the TRAC_ENV as an overall default: {{{ {{{#!apache FastCgiConfig -initial-env TRAC_ENV=/path/to/env/trac }}} Alternatively, you can serve multiple Trac projects in a directory by adding this: {{{ {{{#!apache FastCgiConfig -initial-env TRAC_ENV_PARENT_DIR=/parent/dir/of/projects }}} === Set up with mod_fcgid === Configure ScriptAlias (see TracCgi for details), but call trac.fcgi instead of trac.cgi. Note that slash at the end - it is important. {{{ You can also specify the PYTHON_EGG_CACHE environment variable using a second -initial-env directive: {{{#!apache FastCgiConfig -initial-env TRAC_ENV=/var/lib/trac \ -initial-env PYTHON_EGG_CACHE=/var/lib/trac/plugin-cache }}} === Set up with mod_fcgid Configure ScriptAlias (see TracCgi for details), but call trac.fcgi instead of trac.cgi: {{{#!apache ScriptAlias /trac /path/to/www/trac/cgi-bin/trac.fcgi/ }}} To 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 alternative environment setup below. {{{ Note the slash at the end. To 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: {{{#!apache DefaultInitEnv TRAC_ENV /path/to/env/trac/ }}} === alternative environment setup === A better method to specify path to Trac environment is to embed the path into trac.fcgi script itself. That doesn't require configuration of server environment variables, works for both FastCgi modules (and for [http://www.lighttpd.net/ lighttpd] and CGI as well): {{{ === Alternative environment setup A 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: {{{#!python import os os.environ['TRAC_ENV'] = "/path/to/projectenv" }}} or {{{ or: {{{#!python import os os.environ['TRAC_ENV_PARENT_DIR'] = "/path/to/project/parent/dir" }}} With this method different projects can be supported by using different .fcgi scripts with different ScriptAliases. With this method different projects can be supported by using different .fcgi scripts with different ScriptAliases. See [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: {{{ {{{#!apache ScriptAlias / /srv/tracsite/cgi-bin/trac.fcgi/ }}} == Simple Cherokee Configuration == The configuration on Cherokee's side is quite simple. You will only need to know that you can 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. First set up an information source in cherokee-admin with a local interpreter. == Cherokee Configuration Configuring [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. First set up an information source in cherokee-admin with a local interpreter: {{{ After 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. The 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). 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.\\ Python-flup is a dependency which provides trac with SCGI capability. You can install it on debian based systems with: {{{ The 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). '''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: {{{#!sh sudo apt-get install python-flup }}} == Simple Lighttpd Configuration == The FastCGI front-end was developed primarily for use with alternative webservers, such as [http://www.lighttpd.net/ lighttpd]. lighttpd 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. For using trac.fcgi(prior to 0.11) / fcgi_frontend.py (0.11) with lighttpd add the following to your lighttpd.conf: == Lighttpd Configuration The FastCGI front-end was developed primarily for use with alternative webservers, such as [http://www.lighttpd.net/ Lighttpd]. Lighttpd 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. For using trac.fcgi(prior to 0.11) / fcgi_frontend.py (0.11) with Lighttpd add the following to your lighttpd.conf: {{{ #var.fcgi_binary="/usr/bin/python /path/to/fcgi_frontend.py" # 0.11 if installed with easy_setup, it is inside the egg directory }}} Note 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). Note 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 should be fixed since lighttpd 1.4.23, and you may need to add "fix-root-scriptname" => "enable" as parameter of fastcgi.server. Note 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. Note 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. For using two projects with lighttpd add the following to your lighttpd.conf: ) }}} Note that field values are different.  If you prefer setting the environment variables in the .fcgi scripts, then copy/rename trac.fcgi, e.g., to first.fcgi and second.fcgi, and reference them in the above settings. Note that the above will result in different processes in any event, even if both are running from the same trac.fcgi script. {{{ #!div class=important '''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. Note 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. Note that the above will result in different processes in any event, even if both are running from the same trac.fcgi script. {{{#!div class=important '''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. }}} ) }}} Note that lighttpd (I use version 1.4.3) stopped if password file doesn't exist. Note that lighttpd doesn't support 'valid-user' in versions prior to 1.3.16. Conditional configuration is also useful for mapping static resources, i.e. serving out images and CSS directly instead of through FastCGI: }}} Note that Lighttpd (v1.4.3) stops if the password file doesn't exist. Note that Lighttpd doesn't support 'valid-user' in versions prior to 1.3.16. Conditional configuration is also useful for mapping static resources, ie serving out images and CSS directly instead of through FastCGI: {{{ # Aliasing functionality is needed } }}} The 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. Also there is another way to handle multiple projects and it's to use TRAC_ENV_PARENT_DIR instead of TRAC_ENV and use global auth, let's see an example: Also there is another way to handle multiple projects and it uses TRAC_ENV_PARENT_DIR instead of TRAC_ENV as well as global authentication: {{{ #  This is for handling multiple projects }}} Changing date/time format also supported by lighttpd over environment variable LC_TIME Changing date/time format also supported by lighttpd over environment variable LC_TIME: {{{ fastcgi.server = ("/trac" => ) }}} For details about languages specification see [trac:TracFaq TracFaq] question 2.13. Other important information like the [wiki:TracInstall#MappingStaticResources mapping static resources advices] are useful for non-fastcgi specific installation aspects. ] Relaunch lighttpd, and browse to http://yourhost.example.org/trac to access Trac. Note 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. == Simple !LiteSpeed Configuration == Relaunch Lighttpd and browse to http://yourhost.example.org/trac to access Trac. Note 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. == !LiteSpeed Configuration The FastCGI front-end was developed primarily for use with alternative webservers, such as [http://www.litespeedtech.com/ LiteSpeed]. !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. 1. Please make sure you have first have a working install of a Trac project. Test install with “tracd” first. 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: 1. Please make sure you have a working install of a Trac project. Test install with "tracd" first. 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: {{{ http://yourdomain.com/trac/ }}} 3. Go “!TracVhost → External Apps” tab and create a new “External Application”. 1. Go "!TracVhost → External Apps" tab and create a new "External Application": {{{ Name: MyTracFCGI Instances: 10 }}} 4. Optional. If you need to use htpasswd based authentication. Go to “!TracVhost → Security” tab and create a new security “Realm”. {{{ 1. Optional: If you need to use htpasswd based authentication. Go to "!TracVhost → Security" tab and create a new security Realm: {{{ DB Type: Password File Realm Name: MyTracUserDB               <--- any name you wish and referenced later User DB Location: /fullpathto/htpasswd <--- path to your htpasswd file }}} 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. 5. Go to “!PythonVhost → Contexts” and create a new “FCGI Context”. {{{ 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. 1. Go to "!PythonVhost → Contexts" and create a new FCGI Context: {{{ URI: /trac/                              <--- URI path to bind to python fcgi app we created Fast CGI App: [VHost Level] MyTractFCGI  <--- select the trac fcgi extapp we just created Fast CGI App: [VHost Level] MyTractFCGI  <--- select the Trac fcgi extapp we just created Realm: TracUserDB                        <--- only if (4) is set. select realm created in (4) }}} 6. Modify /fullpathto/mytracproject/conf/trac.ini {{{ 1. Modify /fullpathto/mytracproject/conf/trac.ini: {{{ #find/set base_rul, url, and link variables base_url = http://yourdomain.com/trac/ <--- base url to generate correct links to link = http://yourdomain.com/trac/     <--- link of graphic logo }}} 7. Restart !LiteSpeed, “lswsctrl restart”, and access your new Trac project at: {{{ http://yourdomain.com/trac/ }}} == Simple Nginx Configuration == Nginx is able to communicate with FastCGI processes, but can not spawn them. So you need to start FastCGI server for Trac separately. 1. Restart !LiteSpeed: lswsctrl restart, and access your new Trac project at {{{http://yourdomain.com/trac/}}}. == Nginx Configuration [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. 1. Nginx configuration with basic authentication handled by Nginx - confirmed to work on 0.6.32 {{{ {{{#!nginx server { listen       10.9.8.7:443; ssl_prefer_server_ciphers   on; # (Or ^/some/prefix/(.*). if ($uri ~ ^/(.*)) { set$path_info /$1; # it makes sense to serve static resources through Nginx (or ~ [/some/prefix]/chrome/(.*)) location ~ /chrome/(.*) { alias /home/trac/instance/static/htdocs/$1; } # it makes sense to serve static resources through Nginx location /chrome/ { alias /home/trac/instance/static/htdocs/; } # You can copy this whole location to location [/some/prefix]/login # You can copy this whole location to location [/some/prefix](/login) # and remove the auth entries below if you want Trac to enforce # authorization where appropriate instead of needing to authenticate # for accessing the whole site. # (Or location /some/prefix.) location / { # (Or ~ location /some/prefix(/.*).) location ~ (/.*) { auth_basic            "trac realm"; auth_basic_user_file /home/trac/htpasswd; # (Or fastcgi_param  SCRIPT_NAME  /some/prefix.) fastcgi_param  SCRIPT_NAME        ""; fastcgi_param  PATH_INFO          $path_info; fastcgi_param PATH_INFO$1; ## WSGI NEEDED VARIABLES - trac warns about them } }}} 2. Modified trac.fcgi: {{{ 1. Modified trac.fcgi: {{{#!python #!/usr/bin/env python import os }}} 3. reload nginx and launch trac.fcgi like that: {{{ 1. Reload nginx and launch trac.fcgi: {{{#!sh trac@trac.example ~ \$ ./trac-standalone-fcgi.py }}} The above assumes that: * There is a user named 'trac' for running trac instances and keeping trac environments in its home directory. * /home/trac/instance contains a trac environment * There is a user named 'trac' for running Trac instances and keeping Trac environments in its home directory * /home/trac/instance contains a Trac environment * /home/trac/htpasswd contains authentication information * /home/trac/run is owned by the same group the nginx runs under * /home/trac/run is owned by the same group the Nginx runs under * and if your system is Linux the /home/trac/run has setgid bit set (chmod g+s run) * and patch from ticket #T7239 is applied, or you'll have to fix the socket file permissions every time Unfortunately nginx does not support variable expansion in fastcgi_pass directive. Thus it is not possible to serve multiple trac instances from one server block. If you worry enough about security, run trac instances under separate users. Another way to run trac as a FCGI external application is offered in ticket #T6224 * and patch from [trac:#7239] is applied, or you'll have to fix the socket file permissions every time Unfortunately Nginx does not support variable expansion in fastcgi_pass directive. Thus it is not possible to serve multiple Trac instances from one server block. If you worry enough about security, run Trac instances under separate users. Another way to run Trac as a FCGI external application is offered in [trac:#6224]. ---- See also:  TracGuide, TracInstall, [wiki:TracModWSGI ModWSGI], [wiki:TracCgi CGI], [wiki:TracModPython ModPython], [trac:TracNginxRecipe TracNginxRecipe] See also: TracGuide, TracInstall, [wiki:TracModWSGI ModWSGI], [wiki:TracCgi CGI], [wiki:TracModPython ModPython], [trac:TracNginxRecipe TracNginxRecipe]