Check existence and state of a service on windows machine using win_service

[ishan jain]

I am trying to provision windows server 2012 R2 machine with ansible and for that i need to gather some custom facts about the running services. I tried getting the information via the win_service module like this:

---

- hosts: windows

  tasks:

    - name: check services

      win_service:

            name: test1

      register: result

      ignore_errors: yes

    - debug: msg="{{result}}"

    - debug: msg="service is running"

      when: result.state == 'running'

This works fine if the service exists but in case the service does not exist, i get ugly looking failed message in the win_service task and as there is no common member name in the registered variable 'result', i am not sure how to first check if the service really exist and then proceed to do something further. Is there a better way to check if service exists and if yes, what is its state ?

[J Hawkesworth]

I suggest you add a task, before your win_service task that installs the service if it is not yet installed.  Depending on what the service is, you might be able to use win_package to install it.  If it is already installed, there is not much to loose by running the win_package task a second time, as it will only install if not installed.

When provisioning, I like to write playbooks that drag the machine into the state that I want it in rather than trying to write playbooks that have to handle lots of different possiblities that might exist on the different machines.

Hope this helps,

Jon

[ishan jain]

Agreed with your point - we should drag the machine in the state we want. But in my case the number 1 priority is to make the script idempotent, which seems like quite a thing on windows end.

I not installing anything on the windows end and my application will run as standalone service, no installation required. I am using NSSM to install the services, so win_package is not going to be of any use to me.

To make my script idempotent, i must first check if the service exists, before i invoke NSSM to create the service. I can live with the complicated conditionals i will have in my scripts, but they must be idempotent in the end. 

The solution where i check the service with win_service works fine except that in the case it is not present, it will give me a lot of red statements. What i am looking for is a better way where i can simply check that if a given service is created or not. I wish NSSM had some API to check for that.

[J Hawkesworth]

You could run a raw powershell command like

Get-Service nameOfService -ErrorAction SilentlyContinue

and then register the result, then check 

You would need the '-ErrorAction SilentlyContinue' bit otherwise when the service doesn't exist, Get-Service will fail.

also if you prefer you could do something similar with the sc.exe like this

sc.exe query serviceName

Hope this helps.

[ishan jain]

Both get-service and sc.exe returns textual results. I will have to match strings to check if service exists and its state and i never like to base my conditions on pattern matching.

The best  solution i could thing of is to go with win_service and define a failed_when situation along with. At least i will have the results in proper json objects.

[CORLEONE##]

win_service returns values such as exists(which is false or true depending whether the service is absent or present).So you can just use something like

{when:  win_service_register.exists} to any task which u want to execute only if the service is present. .