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author | Nishanth Amuluru | 2011-01-11 22:41:51 +0530 |
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committer | Nishanth Amuluru | 2011-01-11 22:41:51 +0530 |
commit | b03203c8cb991c16ac8a3d74c8c4078182d0bb48 (patch) | |
tree | 7cf13b2deacbfaaec99edb431b83ddd5ea734a52 /parts/django/docs/howto/deployment/fastcgi.txt | |
parent | 0c50203cd9eb94b819883c3110922e873f003138 (diff) | |
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removed all the buildout files
Diffstat (limited to 'parts/django/docs/howto/deployment/fastcgi.txt')
-rw-r--r-- | parts/django/docs/howto/deployment/fastcgi.txt | 400 |
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diff --git a/parts/django/docs/howto/deployment/fastcgi.txt b/parts/django/docs/howto/deployment/fastcgi.txt deleted file mode 100644 index ea14b97..0000000 --- a/parts/django/docs/howto/deployment/fastcgi.txt +++ /dev/null @@ -1,400 +0,0 @@ -============================================ -How to use Django with FastCGI, SCGI, or AJP -============================================ - -.. highlight:: bash - -Although the current preferred setup for running Django is :doc:`Apache with -mod_wsgi </howto/deployment/modwsgi>`, many people use shared hosting, on -which protocols such as FastCGI, SCGI or AJP are the only viable options. In -some setups, these protocols may provide better performance than mod_wsgi_. - -.. admonition:: Note - - This document primarily focuses on FastCGI. Other protocols, such as SCGI - and AJP, are also supported, through the ``flup`` Python package. See the - Protocols_ section below for specifics about SCGI and AJP. - -Essentially, FastCGI is an efficient way of letting an external application -serve pages to a Web server. The Web server delegates the incoming Web requests -(via a socket) to FastCGI, which executes the code and passes the response back -to the Web server, which, in turn, passes it back to the client's Web browser. - -Like mod_python, FastCGI allows code to stay in memory, allowing requests to be -served with no startup time. Unlike mod_python_ (or `mod_perl`_), a FastCGI -process doesn't run inside the Web server process, but in a separate, -persistent process. - -.. _mod_wsgi: http://code.google.com/p/modwsgi/ -.. _mod_perl: http://perl.apache.org/ -.. _mod_python: http://www.modpython.org/ - -.. admonition:: Why run code in a separate process? - - The traditional ``mod_*`` arrangements in Apache embed various scripting - languages (most notably PHP, Python and Perl) inside the process space of - your Web server. Although this lowers startup time -- because code doesn't - have to be read off disk for every request -- it comes at the cost of - memory use. For mod_python, for example, every Apache process gets its own - Python interpreter, which uses up a considerable amount of RAM. - - Due to the nature of FastCGI, it's even possible to have processes that run - under a different user account than the Web server process. That's a nice - security benefit on shared systems, because it means you can secure your - code from other users. - -Prerequisite: flup -================== - -Before you can start using FastCGI with Django, you'll need to install flup_, a -Python library for dealing with FastCGI. Version 0.5 or newer should work fine. - -.. _flup: http://www.saddi.com/software/flup/ - -Starting your FastCGI server -============================ - -FastCGI operates on a client-server model, and in most cases you'll be starting -the FastCGI process on your own. Your Web server (be it Apache, lighttpd, or -otherwise) only contacts your Django-FastCGI process when the server needs a -dynamic page to be loaded. Because the daemon is already running with the code -in memory, it's able to serve the response very quickly. - -.. admonition:: Note - - If you're on a shared hosting system, you'll probably be forced to use - Web server-managed FastCGI processes. See the section below on running - Django with Web server-managed processes for more information. - -A Web server can connect to a FastCGI server in one of two ways: It can use -either a Unix domain socket (a "named pipe" on Win32 systems), or it can use a -TCP socket. What you choose is a manner of preference; a TCP socket is usually -easier due to permissions issues. - -To start your server, first change into the directory of your project (wherever -your :doc:`manage.py </ref/django-admin>` is), and then run the -:djadmin:`runfcgi` command:: - - ./manage.py runfcgi [options] - -If you specify ``help`` as the only option after :djadmin:`runfcgi`, it'll -display a list of all the available options. - -You'll need to specify either a :djadminopt:`socket`, a :djadminopt:`protocol` -or both :djadminopt:`host` and :djadminopt:`port`. Then, when you set up your -Web server, you'll just need to point it at the host/port or socket you -specified when starting the FastCGI server. See the examples_, below. - -Protocols ---------- - -Django supports all the protocols that flup_ does, namely fastcgi_, `SCGI`_ and -`AJP1.3`_ (the Apache JServ Protocol, version 1.3). Select your preferred -protocol by using the :djadminopt:`protocol=\<protocol_name\> <protocol>` option -with ``./manage.py runfcgi`` -- where ``<protocol_name>`` may be one of: -``fcgi`` (the default), ``scgi`` or ``ajp``. For example:: - - ./manage.py runfcgi protocol=scgi - -.. _flup: http://www.saddi.com/software/flup/ -.. _fastcgi: http://www.fastcgi.com/ -.. _SCGI: http://python.ca/scgi/protocol.txt -.. _AJP1.3: http://tomcat.apache.org/connectors-doc/ajp/ajpv13a.html - -Examples --------- - -Running a threaded server on a TCP port:: - - ./manage.py runfcgi method=threaded host=127.0.0.1 port=3033 - -Running a preforked server on a Unix domain socket:: - - ./manage.py runfcgi method=prefork socket=/home/user/mysite.sock pidfile=django.pid - -.. admonition:: Socket security - - Django's default umask requires that the webserver and the Django fastcgi - process be run with the same group **and** user. For increased security, - you can run them under the same group but as different users. If you do - this, you will need to set the umask to 0002 using the ``umask`` argument - to ``runfcgi``. - -Run without daemonizing (backgrounding) the process (good for debugging):: - - ./manage.py runfcgi daemonize=false socket=/tmp/mysite.sock maxrequests=1 - -Stopping the FastCGI daemon ---------------------------- - -If you have the process running in the foreground, it's easy enough to stop it: -Simply hitting ``Ctrl-C`` will stop and quit the FastCGI server. However, when -you're dealing with background processes, you'll need to resort to the Unix -``kill`` command. - -If you specify the :djadminopt:`pidfile` option to :djadmin:`runfcgi`, you can -kill the running FastCGI daemon like this:: - - kill `cat $PIDFILE` - -...where ``$PIDFILE`` is the ``pidfile`` you specified. - -To easily restart your FastCGI daemon on Unix, try this small shell script:: - - #!/bin/bash - - # Replace these three settings. - PROJDIR="/home/user/myproject" - PIDFILE="$PROJDIR/mysite.pid" - SOCKET="$PROJDIR/mysite.sock" - - cd $PROJDIR - if [ -f $PIDFILE ]; then - kill `cat -- $PIDFILE` - rm -f -- $PIDFILE - fi - - exec /usr/bin/env - \ - PYTHONPATH="../python:.." \ - ./manage.py runfcgi socket=$SOCKET pidfile=$PIDFILE - -Apache setup -============ - -To use Django with Apache and FastCGI, you'll need Apache installed and -configured, with `mod_fastcgi`_ installed and enabled. Consult the Apache -documentation for instructions. - -Once you've got that set up, point Apache at your Django FastCGI instance by -editing the ``httpd.conf`` (Apache configuration) file. You'll need to do two -things: - - * Use the ``FastCGIExternalServer`` directive to specify the location of - your FastCGI server. - * Use ``mod_rewrite`` to point URLs at FastCGI as appropriate. - -.. _mod_fastcgi: http://www.fastcgi.com/mod_fastcgi/docs/mod_fastcgi.html - -Specifying the location of the FastCGI server ---------------------------------------------- - -The ``FastCGIExternalServer`` directive tells Apache how to find your FastCGI -server. As the `FastCGIExternalServer docs`_ explain, you can specify either a -``socket`` or a ``host``. Here are examples of both: - -.. code-block:: apache - - # Connect to FastCGI via a socket / named pipe. - FastCGIExternalServer /home/user/public_html/mysite.fcgi -socket /home/user/mysite.sock - - # Connect to FastCGI via a TCP host/port. - FastCGIExternalServer /home/user/public_html/mysite.fcgi -host 127.0.0.1:3033 - -In either case, the file ``/home/user/public_html/mysite.fcgi`` doesn't -actually have to exist. It's just a URL used by the Web server internally -- a -hook for signifying which requests at a URL should be handled by FastCGI. (More -on this in the next section.) - -.. _FastCGIExternalServer docs: http://www.fastcgi.com/mod_fastcgi/docs/mod_fastcgi.html#FastCgiExternalServer - -Using mod_rewrite to point URLs at FastCGI ------------------------------------------- - -The second step is telling Apache to use FastCGI for URLs that match a certain -pattern. To do this, use the `mod_rewrite`_ module and rewrite URLs to -``mysite.fcgi`` (or whatever you specified in the ``FastCGIExternalServer`` -directive, as explained in the previous section). - -In this example, we tell Apache to use FastCGI to handle any request that -doesn't represent a file on the filesystem and doesn't start with ``/media/``. -This is probably the most common case, if you're using Django's admin site: - -.. code-block:: apache - - <VirtualHost 12.34.56.78> - ServerName example.com - DocumentRoot /home/user/public_html - Alias /media /home/user/python/django/contrib/admin/media - RewriteEngine On - RewriteRule ^/(media.*)$ /$1 [QSA,L,PT] - RewriteCond %{REQUEST_FILENAME} !-f - RewriteRule ^/(.*)$ /mysite.fcgi/$1 [QSA,L] - </VirtualHost> - -.. _mod_rewrite: http://httpd.apache.org/docs/2.0/mod/mod_rewrite.html - -Django will automatically use the pre-rewrite version of the URL when -constructing URLs with the ``{% url %}`` template tag (and similar methods). - -lighttpd setup -============== - -lighttpd_ is a lightweight Web server commonly used for serving static files. It -supports FastCGI natively and, thus, is a good choice for serving both static -and dynamic pages, if your site doesn't have any Apache-specific needs. - -.. _lighttpd: http://www.lighttpd.net/ - -Make sure ``mod_fastcgi`` is in your modules list, somewhere after -``mod_rewrite`` and ``mod_access``, but not after ``mod_accesslog``. You'll -probably want ``mod_alias`` as well, for serving admin media. - -Add the following to your lighttpd config file: - -.. code-block:: lua - - server.document-root = "/home/user/public_html" - fastcgi.server = ( - "/mysite.fcgi" => ( - "main" => ( - # Use host / port instead of socket for TCP fastcgi - # "host" => "127.0.0.1", - # "port" => 3033, - "socket" => "/home/user/mysite.sock", - "check-local" => "disable", - ) - ), - ) - alias.url = ( - "/media" => "/home/user/django/contrib/admin/media/", - ) - - url.rewrite-once = ( - "^(/media.*)$" => "$1", - "^/favicon\.ico$" => "/media/favicon.ico", - "^(/.*)$" => "/mysite.fcgi$1", - ) - -Running multiple Django sites on one lighttpd ---------------------------------------------- - -lighttpd lets you use "conditional configuration" to allow configuration to be -customized per host. To specify multiple FastCGI sites, just add a conditional -block around your FastCGI config for each site:: - - # If the hostname is 'www.example1.com'... - $HTTP["host"] == "www.example1.com" { - server.document-root = "/foo/site1" - fastcgi.server = ( - ... - ) - ... - } - - # If the hostname is 'www.example2.com'... - $HTTP["host"] == "www.example2.com" { - server.document-root = "/foo/site2" - fastcgi.server = ( - ... - ) - ... - } - -You can also run multiple Django installations on the same site simply by -specifying multiple entries in the ``fastcgi.server`` directive. Add one -FastCGI host for each. - -Cherokee setup -============== - -Cherokee is a very fast, flexible and easy to configure Web Server. It -supports the widespread technologies nowadays: FastCGI, SCGI, PHP, CGI, SSI, -TLS and SSL encrypted connections, Virtual hosts, Authentication, on the fly -encoding, Load Balancing, Apache compatible log files, Data Base Balancer, -Reverse HTTP Proxy and much more. - -The Cherokee project provides a documentation to `setting up Django`_ with Cherokee. - -.. _setting up Django: http://www.cherokee-project.com/doc/cookbook_django.html - -Running Django on a shared-hosting provider with Apache -======================================================= - -Many shared-hosting providers don't allow you to run your own server daemons or -edit the ``httpd.conf`` file. In these cases, it's still possible to run Django -using Web server-spawned processes. - -.. admonition:: Note - - If you're using Web server-spawned processes, as explained in this section, - there's no need for you to start the FastCGI server on your own. Apache - will spawn a number of processes, scaling as it needs to. - -In your Web root directory, add this to a file named ``.htaccess``: - -.. code-block:: apache - - AddHandler fastcgi-script .fcgi - RewriteEngine On - RewriteCond %{REQUEST_FILENAME} !-f - RewriteRule ^(.*)$ mysite.fcgi/$1 [QSA,L] - -Then, create a small script that tells Apache how to spawn your FastCGI -program. Create a file ``mysite.fcgi`` and place it in your Web directory, and -be sure to make it executable: - -.. code-block:: python - - #!/usr/bin/python - import sys, os - - # Add a custom Python path. - sys.path.insert(0, "/home/user/python") - - # Switch to the directory of your project. (Optional.) - # os.chdir("/home/user/myproject") - - # Set the DJANGO_SETTINGS_MODULE environment variable. - os.environ['DJANGO_SETTINGS_MODULE'] = "myproject.settings" - - from django.core.servers.fastcgi import runfastcgi - runfastcgi(method="threaded", daemonize="false") - -Restarting the spawned server ------------------------------ - -If you change any Python code on your site, you'll need to tell FastCGI the -code has changed. But there's no need to restart Apache in this case. Rather, -just reupload ``mysite.fcgi``, or edit the file, so that the timestamp on the -file will change. When Apache sees the file has been updated, it will restart -your Django application for you. - -If you have access to a command shell on a Unix system, you can accomplish this -easily by using the ``touch`` command:: - - touch mysite.fcgi - -Serving admin media files -========================= - -Regardless of the server and configuration you eventually decide to use, you -will also need to give some thought to how to serve the admin media files. The -advice given in the :ref:`modpython <serving-the-admin-files>` documentation -is also applicable in the setups detailed above. - -Forcing the URL prefix to a particular value -============================================ - -Because many of these fastcgi-based solutions require rewriting the URL at -some point inside the Web server, the path information that Django sees may not -resemble the original URL that was passed in. This is a problem if the Django -application is being served from under a particular prefix and you want your -URLs from the ``{% url %}`` tag to look like the prefix, rather than the -rewritten version, which might contain, for example, ``mysite.fcgi``. - -Django makes a good attempt to work out what the real script name prefix -should be. In particular, if the Web server sets the ``SCRIPT_URL`` (specific -to Apache's mod_rewrite), or ``REDIRECT_URL`` (set by a few servers, including -Apache + mod_rewrite in some situations), Django will work out the original -prefix automatically. - -In the cases where Django cannot work out the prefix correctly and where you -want the original value to be used in URLs, you can set the -:setting:`FORCE_SCRIPT_NAME` setting in your main ``settings`` file. This sets the -script name uniformly for every URL served via that settings file. Thus you'll -need to use different settings files if you want different sets of URLs to -have different script names in this case, but that is a rare situation. - -As an example of how to use it, if your Django configuration is serving all of -the URLs under ``'/'`` and you wanted to use this setting, you would set -``FORCE_SCRIPT_NAME = ''`` in your settings file. |