Paste Script
============

:author: Ian Bicking <ianb@colorstudy.com>
:revision: $Rev: 5844 $
:date: $LastChangedDate: 2006-10-22 15:31:05 -0500 (Sun, 22 Oct 2006) $

.. contents::

Introduction
------------

If you are developer, see the `Developer Documentation
<developer.html>`_; this will tell you how to add commands and
templates to ``paster``.  For a list of updates see the `news file
<news.html>`_.

Paste Script is released under the `MIT license
<http://www.opensource.org/licenses/mit-license.php>`_.

Status
------

Paste Script has passed version 1.0.  Paste Script is an actively
maintained project.  As of 1.0, we'll make a strong effort to maintain
backward compatibility.  This will include deprecation warnings when
necessary.  Major changes will take place under new functions or with
new entry points.

``paster serve``
----------------

The one useful command you may want to know about for ``paster`` is
``paster serve``.  This serves an application described in a `Paste
Deploy <http://pythonpaste.org/deploy>`_ configuration file.

Configuration
-------------

A quickstart (and example), if not complete explanation::

    [app:main]
    use = egg:PasteEnabledPackage
    option1 = foo
    option2 = bar

    [server:main]
    use = egg:PasteScript#wsgiutils
    host = 127.0.0.1
    port = 80

``egg:PasteEnabledPackage`` refers to some package that has been
prepared for use with paste.deploy, and options given to that
package.  If you are starting out with some framework, you'll have to
reference some documentation for that framework to paste-deploy-ify
your application (or read the paste.deploy documentation).

In the same file is a server description.
``egg:PasteScript#wsgiutils`` is a server (named ``wsgiutils``)
provided by this package, based on `WSGIUtils
<http://www.owlfish.com/software/wsgiutils/>`_.  And we pass various
options particular to that server.

Other packages can provide servers, but currently Paste Script
includes glue for these:

``wsgiutils``:

    A `SimpleHTTPServer
    <http://python.org/doc/current/lib/module-SimpleHTTPServer.html>`_
    based threaded HTTP server, using `WSGIUtils
    <http://www.owlfish.com/software/wsgiutils/>`_.

``flup_(scgi|fcgi|ajp)_(thread|fork)``:

    This set of servers supports `SCGI
    <http://www.mems-exchange.org/software/scgi/>`_, `FastCGI
    <http://www.fastcgi.com/>`_ and `AJP
    <http://jakarta.apache.org/tomcat/connectors-doc/common/ajpv13a.html>`_
    protocols, for connection an external web server (like Apache) to
    your application.  Both threaded and forking versions are
    available.  This is based on `flup
    <http://www.saddi.com/software/flup/>`_.

There is the start of support for `twisted.web2
<http://twistedmatrix.com/projects/web2/>`_ in
``paste.script.twisted_web2_server``; patches welcome.

Running the Server
------------------

``paster serve --help`` gives useful output::

  usage: /usr/local/bin/paster serve [options] CONFIG_FILE [start|stop|restart|status]
  Serve the described application

  If start/stop/restart is given, then it will start (normal
  operation), stop (--stop-daemon), or do both.  You probably want
  ``--daemon`` as well for stopping.

  Options:
    -h, --help            show this help message and exit
    -v, --verbose         
    -q, --quiet           
    -nNAME, --app-name=NAME
                          Load the named application (default main)
    -sSERVER_TYPE, --server=SERVER_TYPE
                          Use the named server.
    --server-name=SECTION_NAME
                          Use the named server as defined in the configuration
                          file (default: main)
    --daemon              Run in daemon (background) mode
    --pid-file=FILENAME   Save PID to file (default to paster.pid if running in
                          daemon mode)
    --log-file=LOG_FILE   Save output to the given log file (redirects stdout)
    --reload              Use auto-restart file monitor
    --reload-interval=RELOAD_INTERVAL
                          Seconds between checking files (low number can cause
                          significant CPU usage)
    --status              Show the status of the (presumably daemonized) server
    --user=USERNAME       Set the user (usually only possible when run as root)
    --group=GROUP         Set the group (usually only possible when run as root)
    --stop-daemon         Stop a daemonized server (given a PID file, or default
                          paster.pid file)

Basically you give it a configuration file.  If you don't do anything
else, it'll serve the ``[app:main]`` application with the
``[server:main]`` server.  You can pass in ``--server-name=foo`` to
serve the ``[server:foo]`` section (or even
``--server-name=config:foo.ini`` to use a separate configuration
file).

Similarly you can use ``--app-name=foo`` to serve ``[app:foo]``.

``--daemon`` will run the server in the backgroup, ``--user`` and
``--group`` will set the user, as you might want to do from a start
script (run as root).  If you don't give a ``--pid-file`` it will
write the pid to ``paster.pid`` (in the current directory).

``--stop-daemon`` will stop the daemon in ``paster.pid`` or whatever
``--pid-file`` you give.  ``--log-file`` will redirect stdout and
stderr to that file.

``--reload`` will start the reload monitor, and restart the server
whenever a file is edited.  This can be a little expensive, but is
very useful during development.

#! Scripts
----------

On Posix (Linux, Unix, etc) systems you can turn your configuration
files into executable scripts.

First make the file executable (``chmod +x config_file.ini``).  The
you should add a line like this to the top of the file::

    #!/usr/bin/env paster

You can include a command and command-line options in an ``[exe]``
section, like::

    [exe]
    command = serve
    daemon = true
    user = nobody
    group = nobody

(use ``true`` and ``false`` for options that don't take an argument).

If you use ``daemon = true`` then you'll be able to use the script as
an rc script, so you can do::

    $ sudo ./config_file.ini start
    $ sudo ./config_file.ini restart

and so forth.

Note that this is a little wonky still on some platforms and shells
(notably it doesn't work under `csh
<http://www.faqs.org/faqs/unix-faq/shell/csh-whynot/>`_).  If you get
an error about "Command config_file.ini not known" then this probably
won't work for you.  In the future an additional script to ``paster``
will be added just for this purpose.
