isotoma.recipe.pound 0.1.12

isotoma.recipe.pound provides buildout_recipes for the configuration of pound. This is a more fully featured recipe than others we've found on PyPI, and supports things like 500 error pages, emergency servers and configurable affinity.

We use the system pound, so this recipe will not install pound for you. If you wish to install pound, use zc.recipe.cmmi perhaps.

An example of a standard setup:

[pound]
recipe = isotoma.recipe.pound
address = 127.0.0.1
port = 8080
session = COOKIE:_ZopeID:3600
err500 = /var/www/emergency/index.html
emergency = 127.0.0.1:8090
backends =
 127.0.0.1:8081
 127.0.0.1:8082
 127.0.0.1:8083

If you use pound or another loadbalancer, you might find isotoma.recipe.portmap useful too.

Mandatory parameters

address
 The address on which to listen for connections
port
 The port on which to listen for connections
backends
 A list of backends, supplied as address:port pairs, separated by whitespace

Optional parameters

executable
 The path to the pound binary. Defaults to /usr/sbin/pound.
poundctl
 The path to the poundctl binary. Defaults to /usr/sbin/poundctl.
user
 The user to run pound as. Defaults to www-data.
group
 The group to run pound as. Defaults to www-data.
logfacility
 The syslog facility to which to send log output. Defaults to local0.
loglevel
 The logging level. Defaults to '2'.
alive
 The number of seconds between checks for aliveness of previously dead backends. Defaults to '30'.
timeout
 The timeout for HTTP requests to a backend. Defaults to '60'.
xHTTP
 Which verbs are accepted. See the pound manual for more details. Defaults to '0' (accept only standard verbs).
template
 The full path to the configuration file template, if you want to customise further. Defaults to pound.cfg template in this package.
session
 If you wish to have session affinity, provide the configuration here as type:id:TTL.
emergency
 If you use an emergency server, provide the configuration here as address:port.
err500
 If you wish to provide an error 500 page, provide the full path here.

Emergency Servers

Recipes are also included to help construct emergency pages. Pound's support for emergency serving is pretty rudimentary, so it needs some help to provide a decent service. The emergency recipe:

- provides an apache configuration suitable for use in this situation
- processes the index page of the emergency content with a simple string substitution, so the image and css resources can be located

The index page of the emergency server is suitable for using in the err500 directive as well.

To use this, you should first create a directory containing an index.html page, and whatever resources are needed to serve this page from apache. In the template, refer to all resouces using $baseurl. For example, if we have:

htdocs/index.html
htdocs/images/logo.png

then in index.html put:

< html >
 < body >
 < img src="$baseurl/images/logo.png" / >
 < /body >
< /html >

Then provide a recipe like:

[emergency]
recipe = isotoma.recipe.pound:emergency
path = /path/to/htdocs
interfaces =
 127.0.0.1:8090
 32.32.32.32:emerg.example.com:80
listen = yes
public = http://www.emerg.example.com
access_log = /var/log/apache2/help.help.access.log
error_log = /var/log/apache2/help.help.error.log
substitute = index.html

$baseurl will be replaced with the value of public.

This might seem like an overly convoluted way of setting up something relatively simple, but if you want valid and testable configurations in continuous integration, staging and production environments this is worth the effort.


Product's homepage

Requirements:

· Python

What's New in This Release: [ read full changelog ]

· Make sure the cycle script is run as run and only when there is a pound socket.