How to store a particular node from an output of a state.sls file in a variable for SaltStack - salt-stack

Question

I'm working on a project where I need to check the status of a service, let's call it RunningService on multiple(more than 500 machines) Windows servers. We are using Saltstack extensively for our deployments.
I'm able to check the status of my service using the below code
status_ser:
module.run:
- name: service.status
- m_name: RunningService
The response that I'm getting on running via this particular code is as below:
----------
ID: status_ser
Function: module.run
Name: service.status
**Result: True**
Comment: Module function service.status executed
Started: 16:20:58.295237
Duration: 78.124 ms
Changes:
----------
ret:
True
Summary for minion-3
------------
Succeeded: 1 (changed=1)
Failed: 0
------------
Total states run: 1
Total run time: 78.124 ms
However, I only want the result part(which could be True or False) out of this in a bigger code probably saved in a variable. And then I'll verify
if var == 'False'
then start RunningService
else
do nothing
endif
How can I get only the result of the service as True or False?
Or a more generic question would be how to store one part of the output as variable or input to something else?
Thanks in advance.

Answer 1

To store the output of a command or salt module as variable (the short answer) is that you use set in a Jinja expression. Like:
{% set service_status = salt['service.status']('RunningService') %}
Either True or False will now be stored in service_status. This can be used in conditional statements. Start service taking example from your question:
{% if not service_status %}
start_service:
module.run:
- service.start:
- name: RunningService
{% endif %}
However, there are few things to consider:
All Jinja expression is evaluated before the States are run
Saltstack can be better used to define the state of service, i.e. if you want a particular service to be running, just define it so.
So, its better to use the Salt state service, which does such checks internally. Then this is all the code you'll need.
start_service:
service.running:
- name: RunningService
Now, whenever you run this state. The service will be started if its not running, and nothing will be done if its already running.