Restart only changed services when using with_items

Archives Ansible Project
1

Hi,

We have a bunch of services, defined as a list of {{ app.name }} and {{ app.version }} variables. We template our upstart files so ansible knows if a new version is being deployed or not (the file only changes if the version number increments). What I’d like to do is only bounce the services whose versions have changed. Here’s what we have at present:

  • name: create upstart configs
    template: src=upstart.conf
    dest=/etc/init/{{ item.name }}.conf
    sudo: yes
    with_items: apps
    register: app_upstart_config

  • name: stop
    with_items: apps
    when: app_upstart_config.changed
    shell: stop {{ item.name }}
    sudo: yes
    ignore_errors: yes

  • name: start
    with_items: apps
    when: app_upstart_config.changed
    shell: start {{ item.name }}
    sudo: yes

What this seems to be doing at present is bouncing all the apps if any of them change. If none of them change it doesn’t bounce them, so it’s nearly there! I suspect that with_items is interacting with register in an unanticipated way. Any help would be gratefully appreciated!

Thanks,
-Darren

2

Take a look at handlers in Ansible for the most elegant way to fire events on change - what you have here is fairly non-idiomatic.

Also the repeating of “sudo” here can be simplified by moving “sudo” up to the play level.

Also you should be using the service module and declaring state versus running explicit commands.

There was a minor bug on the most recent 1.6.X with handlers that would bounce them all on a single change which is already fixed in the development branch, and we’re cutting another small update after we close a few more larger tickets.