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2019-07-31 Stackstorm

Python Action Runner

Python Action Runner Overview#

The official stackstorm docs don’t really go into detail into using the python-action-runners

The first port of call is to read that documentation but when you need a little more, check below.

Need to Know#

The python action runner uses python 2, that is what it is. So your python code should be compatible.

You need to create a class that extends st2common.runners.base_action.Action

So create your class with:

from st2common.runners.base_action import Action


class MyTestActionAction(Action):
    def run(self):

Check the examples at stackstorm action examples, which has an example to print out the python version.

When you install a pack, a virtualenv is automatically created. If you are developing a pack that is already installed, you might need to initialise the virtualenv with:

st2 run packs.setup_virtualenv packs=my-pack-name

Virtualenvs are stored at /opt/stackstorm/virtualenvs on a per pack basis

If you are using any external python packages, these need to be specified in requirements.txt in the base directory of the pack, as show in the docs

If the library is not in your packs virtualenv, an attempt will be made to load it from stackstorms default libraries

Action extends st2client.models.core.Resource, which import six and from __future__ import absolute_import. So I think you can do print(x) the python 3 way…but not 100% on this.

If you want parameters you set them in the action definition:

---
name: "delete-domain"
runner_type: "python-script"
description: "Action to delete a domain"
enabled: true
entry_point: "python2_actions/delete_domain.py"
parameters:
domain:
    type: "string"
    description: "domain name to delete"
    required: true

Then ensure your run() method takes additional paramters:

def run(self, domain):
    ...

Developing Pack New Requirements not Picked Up#

The recommended way is to use git to version control your pack, in /opt/stackstorm/packs/my-pack-name.

So commit everything (make sure you have commited your requirements.txt and pack.yaml)

git add .
git commit

Then install your pack after making changes.

st2 pack install file://$PWD