ashd-wsgi(1)

Table of Contents

1. NAME
2. SYNOPSIS
3. DESCRIPTION
4. OPTIONS
5. PROTOCOL
6. EXAMPLES
7. AUTHOR
8. SEE ALSO

1. NAME

ashd-wsgi - WSGI adapter for ashd(7)

2. SYNOPSIS

ashd-wsgi [-hA] [-p MODPATH] [-l LIMIT] HANDLER-MODULE [ARGS…]

3. DESCRIPTION

The ashd-wsgi handler translates ashd(7) requests to WSGI requests, and passes them to a specified Python handler module. The precise Python convention for doing so is described in the PROTOCOL section, below.

ashd-wsgi is a persistent handler, as defined in ashd(7). It uses multithreaded dispatching in a single Python interpreter, which means that WSGI applications that use it need to be thread-safe, but that they can also share all Python data structures and global variables between requests.

The Python module that ashd-wsgi comes with also contains a standard handler module, ashd.wsgidir, which serves individual WSGI applications directly from the files in which they reside and as such makes this program useful as a dirplex(1) handler. Please see its Python documentation for further details.

ashd-wsgi requires the ashd.proto and ashd.util modules, which are only available for CPython. If you want to use some other Python implementation instead, you may want to use the scgi-wsgi(1) program instead, along with callscgi(1).

4. OPTIONS

-h: Print a brief help message to standard output and exit.
-A: Use the convention used by Apache’s mod_wsgi module to find the WSGI application object. See the PROTOCOL section, below, for details.
-p MODPATH: Prepend MODPATH to Python’s sys.path; can be given multiple times. Note that the working directory of ashd-wsgi is not on Python’s module path by default, so if you want to use a module in that directory, you will need to specify "-p .".
-l LIMIT: Allow at most LIMIT requests to run concurrently. If a new request is made when LIMIT requests are executing, the new request will wait up to ten seconds for one of them to complete; if none does, ashd-wsgi will assume that the process is foobar and abort(3).

5. PROTOCOL

When starting, ashd-wsgi will attempt to import the module named by HANDLER-MODULE, look for an object named wmain in that module, call that object passing the ARGS (as Python strings) as positional parameters, and use the returned object as the WSGI application object. If the -A option was specified, it will look for an object named application instead of wmain, and use that object directly as the WSGI application object.

When calling the WSGI application, a new thread is started for each request, in which the WSGI application object is called. All requests run in the same interpreter, so it is guaranteed that data structures and global variables can be shared between requests.

The WSGI environment is the standard CGI environment, including the SCRIPT_FILENAME variable whenever the X-Ash-File header was included in the request.

6. EXAMPLES

The following dirplex(1) configuration can be used for serving WSGI modules directly from the filesystem.

child wsgidir
  exec ashd-wsgi ashd.wsgidir
match
  filename *.wsgi
  handler wsgidir

Since ashd-wsgi is a persistent handler, it can be used directly as a root handler for htparser(1). For instance, if the directory /srv/www/foo contains a wsgi.py file, which declares a standard WSGI application object, it can be served with the following command:

htparser plain:port=8080 -- ashd-wsgi -Ap /srv/www/foo wsgi

7. AUTHOR

Fredrik Tolf <fredrik@dolda2000.com>

8. SEE ALSO

scgi-wsgi(1), ashd(7), http://wsgi.org/