isotoma.recipe.gocaptain 0.0.9

Starting and stopping daemons

The GoCaptain [1] buildout recipe produces a script to start and stop daemons, similar to those you find in /etc/init.d. By default it will inspect your system and either write a “simple” script, such as you might produce yourself or produce a LinuxStandard Base variation, that provides more tooling.

In particular the LSB scripts will try multiple times to shut down your daemon, and will not start it if it is already running.

This package also provides a simple way to produce these scripts from other buildout recipes - see isotoma.recipe.varnish for an example.

The buildout recipe

A simple example would be:

[example]
recipe = isotoma.recipe.gocaptain
daemon = /usr/bin/example
name = example
description = example daemon for that thing i did that time
pidfile = /var/tmp/example.pid
args =
    -P ${example:pidfile}
    -w /var/tmp/example.log

This will produce a script in bin/example that launches your daemon, and shuts it down again later, using the PID in the pidfile.

Options

The mandatory options this recipe accepts are:

daemon

The path to the daemon executable file

name

The name of the daemon, displayed in log messages

description

A longer description, shown on the console during start and stop

pidfile

A path to a file to store the PID of the new daemon in

args

The arguments for the daemon. These will be formatted in the output script as you provide them, with continuations provided as needed

In addition you can provide:

template

A path to the template for your start/stop script. This will be used in preference to the templates provided with this package.

Calling from other code

If you wish to use this from one of your own recipes, I suggest you do something like:

from isotoma.recipe import gocaptain
gc = gocaptain.Automatic()
f = open("/path/to/script", "w")
gc.write(f, daemon="/usr/sbin/thing",
         args="-D -P /path/to/pid",
         name="my thing", description="thing")
f.close()
os.chmod(target, 0755)

The Automatic module will select the Simple or LinuxStandardBase variants, by inspecting your system (very simplisticly!).

License

Copyright 2010 Isotoma Limited

Licensed under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

[1]

The name comes from Cordwainer Smith