saltstack - execute a state inside a reactor written in python

Question

I am trying to create a reactor in Python + Jinja to react to some event. The documentation has fairly good examples on how to create reactors using the YAML format. However, the documentation for creating a reactor in Python is quite lacking.

Here is what I got so far:

#!jinja|py

"""
reactors can be also complete Python programs instead of Jinja + YAML
"""


def run():
    '''
    I can have fairly complex logic here, but it is all executed on the
    master. 
    '''
    # I can define variable like this
    var = "{{ data['id'] }}"  # this is the id of the minion that sent the signal

    # I can call a salt module like this:
    __salt__['pkg.install']('figlet')  # this will install figlet on the master 
    return {}

The documentation states

The SLS file should contain a function called run which returns high state data.

But so far I fail to see how I can target the desired minion from this dictionary. I know I can use the salt API, but I would like to avoid this at the moment.

Can someone here give an example how you can call a state and target and a minion by returning the correct high state data?

I'm not that deep in the reactor topic, but based on your snippet, i would assume the API to be __salt__[moduleName](*args, **kwargs) and based on this is would expect that __salt__['state.highstate']() should call the highstate. — dahrens
oh - while rereading i understand - the above mentioned will highstate the master, right? — dahrens
Yes, this will highstate the master. And what I would like to do, is to cause the reactor to perform something on another node. The example regarding orchestrations are a bit limited. — oz123
hm - at which point your posted file is load? do you hook in as described there. How does your /etc/salt/master.d/reactor.conf looks like? — dahrens
My file is loaded after a signal is sent and the end of the execution of a certain state. — oz123

oz123 oz123 · Accepted Answer · 2016-10-14T08:15:09

So, it turns out, my way of accessing the context data was wrong. There is no need to wrap the python script in Jinja. Unfortunately this is undocumented at the moment. If you write a state or a returner in Python everything that was inside

{{ data }} # in Jinja + YAML

Is now available with a global variable called (not suprisingly) data. This variable is a dictionary too.

#!py

def run():
    '''
    '''
    # I can define variable like this
    var = data['id']   # this is the id of the minion that sent the signal

    return {}

saltstack - execute a state inside a reactor written in python

1 Answers