3

I have an Ansible role which uses handlers to restart services via the systemd module.

- name: restart ntp
  systemd:
    name: ntp
    enabled: yes
    state: restarted
  become: true

- name: restart web server
  systemd:
    name: nginx
    enabled: yes
    state: restarted
  become: true

- name: restart grafana
  systemd:
    name: grafana
    enabled: yes
    state: restarted
  become: true

Is there a way so I could parameterize the three separate handlers into something like this?:

- name: restart {{svcname}}
  systemd:
    name: '{{svcname}}'
    enabled: yes
    state: restarted
  become: true
0xC0000022L
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2 Answers2

4

In ansible 2.7 and earlier versions, variables in handlers name are not populated.
This bug was reported and a correction was lately pushed to devel version.

You need to run ansible from devel, and hope they publish this fix in the next release.

storm
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1

You could set a fact to be the list of services you need restarted by the handlers: 

- name: Tag services to restart
  set_fact:
    services_to_restart:
     - ntp
     - nginx
     - grafana

then your handler becomes:

- name: Restart tagged services
  service:
    name: "{{ item }}"
    state: restarted
  loop: "{{ services_to_restart }} | default('nginx')"

I suggest using a sane default there in case you send an empty list to the service module.

Bruce Becker
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    This will restart all the services for each notification – storm Nov 27 '18 at 12:55
  • That's why you only put the ones you want in the variable – Bruce Becker Nov 27 '18 at 12:56
  • But if a task needs only a restart of ntp, nginx and grafana will be restarted too .. – storm Nov 27 '18 at 13:06
  • @BruceBecker thank you. But this defies the whole purpose of handlers, doesn't it? In order to figure out whether I have to place a particular service name into the list, I'd have to first register a uniquely-named variable and then check whether that task changed anything in a subsequent set_fact task. The point of handlers is to make this whole process seamless and low-maintenance. I'd lose all that by using something like your proposed method, even though it may be technically viable. – 0xC0000022L Nov 27 '18 at 13:24
  • ok, good points. The answer by @storm is also more correct, so I suggest you accept that one as the "correct" one. – Bruce Becker Nov 27 '18 at 14:26