isotoma.recipe.postdeploy 0.0.6

Basic use

Consider a simple yaybu configuration:

resources.append:
    - Execute:
        name: some-script
        command: ${buildout.buildout.directory}/bin/somescript
        user: root
        creates: ${buildout.buildout.directory}/stuff.cfg

You could wire this into buildout like so:

[buildout]
parts =
    postdeploy

[postdeploy]
recipe = isotoma.recipe.postdeploy
config = config.yay

To look at the ‘expanded’ form of your configuration - with all the variables filled in - you can now (after running buildout) do:

$ ./bin/postdeploy show
resources:
  - Execute:
      name: /var/somedir/bin/somescript
      user: root
      creates: /var/somedir/stuff.cfg

This command optionally takes -v which shows a more verbose dump of your configuration.

You can simulate what would happen if the config was applied without harming the system using the simulate command:

$ ./bin/postdeploy simulate
/---------------------------- Execute[some-script] -----------------------------
| # /var/somedir/bin/somescript
\-------------------------------------------------------------------------------

This command will have an exit code of 254 if it thinks no changes are required, 0 if it successfully simulated applying some changes and anything else indicates a problem with your configuration. It makes an ideal monitoring tool as it can warn of manual hacks or incomplete deployments.

Finally you can apply the configuration with apply:

$ ./bin/postdeploy simulate
/---------------------------- Execute[some-script] -----------------------------
| # /var/somedir/bin/somescript
| Here is the stdout from your command
| ....
| ....
| Success!
\-------------------------------------------------------------------------------

Mandatory Parameters

config

A Yay file to apply to this computer. It will have access to metadata in your buildout.

Optional Parameters

searchpath

A set of directories or URLs to search for assets needed to full configure this site.

history.track

A list of values to monitor. This is useful when you have a list of parts that are buildout managed but need symlinking in postdeploy. Using history tracking you can make sure they are removed from the system if they are removed from buildout.

For example:

[buildout]
parts =
    ${parts:apache}
    postdeploy

[vhost1]
<snip>

[parts]
apache =
    vhost1
    vhost2

[postdeploy]
recipe = isotoma.recipe.postdeploy
history.track =
    parts:apache

And in your Yaybu configuration:

resources.append:
  .foreach vhost in history.parts.apache:
    - Link:
          name: /etc/apache2/sites-enabled/${buildout.sitename}-${vhost}
          policy: remove

The first time you run buildout a datafile with the current state is created, Now if you remove vhost2 from your buildout and run postdeploy Yaybu will ensure your symlink is removed. This data persists across multiple buildouts so is safe even if you forget to run postdeploy.

There are multiple history types. The default is removed. Another example is max which will keep track of the largest value a field has ever held. This is useful if you have buildout with a scaleable number of services and want to make sure old services are stopped when you update buildout:

[postdeploy]
history.track =
    environment:zopes max

I could then do something like this from my Yaybu configuration:

.foreach i in range(buildout.environment.zopes, history.environment.zopes):
  - Execute:
      name: stop-forgotten-zope-${i}
      command: kill-command zope${i}
      unless: some-manual-pid-check

history.db

You don’t normally need to change this setting.

Because this recipe has to support Python 2.4 it can’t use Yay as its main datastore. This is the path to a Python shelf.

The default is ${buildout:directory}/var/${partname}-history.db

history.yay

You don’t normally need to change this setting.

The data from history.db is persisted as yay, it is loaded from here when you run bin/postdeploy.

The default is ${buildout:directory}/var/${partname}-history.yay

executable

A python executable to use. Defaults to the same one used to invoke buildout. This is to support Python 2.4 buildouts as Yaybu requires 2.6 or 2.7.

Repository

This software is available from our recipe repository on github.

License

Copyright 2012 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.

0.0.6 (2012-04-08)

• Nothing changed yet.

0.0.5 (2012-04-07)

• Don’t include empty mappings in output

0.0.4 (2012-04-03)

• Process command line options first.

0.0.3 (2012-03-20)

• Now supports tracking maximum versions of fields:

  [postdeploy]
  history.track =
      environment:zopes max

  The default tracking action is called removed.

  In this example, history.environment.zopes would be the largest number of zopes this buildout deployment has had. The use case for this is that your buildout just destroyed the start/stop scripts for those olds zopes and you want to make sure they were actually stopped. I could then do something like this from my Yaybu configuration:

  .foreach i in range(buildout.environment.zopes, history.environment.zopes):
    - Execute:
        name: stop-forgotten-zope-${i}
        command: kill-command zope${i}
        unless: some-manual-pid-check

0.0.2 (2012-03-17)

• Any sections that are simple metadata and not referenced from a part will now be available in postdeploy configuration. Note that if a section isn’t referenced by an installed part and uses variables then it can’t be included: the act of inspecting it might cause additional buildout recipes to be executed.

0.0.1 (2012-03-16)

• Fix packaging

0.0.0 (2012-03-16)

• Initial release.