Either/or tasks

[Jon Warbrick]

Apologies if this is a FAQ, but I haven't found been able to find it
anywhere.

I keep wanting a pattern where something happens if a variable is true and
something positively doesn't happen if the variable is false (or unset).
For example having a service running or not running. Is there any way to
achieve this other than having pairs of tasks with inverted when clauses?

e.g:

- name: be sure openais is running and enabled
service: name=openais state=running enabled=yes
when: enable_service_address is defined and enable_service_address

- name: be sure openais is NOT running and NOT enabled
service: name=openais state=stopped enabled=no
when: enable_service_address is not defined or not enable_service_address

Or, as an other example, creating or removing a marker file (which seems
to be further complicated by needing 'copy' for create and 'file' for
remove):

- name: Set standalone marker file
copy: content='' dest=/var/role-standalone
when: '"standalone" in group_names'

- name: Unset standalone marker file
file: path=/var/role-standalone state=absent
when: '"standalone" not in group_names'

Jon.

--
Jon Warbrick
Information Systems Manager, University of Cambridge Information Services

[Brian Coca]

not currently, what you have is what works.

--
Brian Coca

[Jon Warbrick]

On Wed, 17 Dec 2014, Brian Coca wrote:

> not currently, what you have is what works.

Ta. At least I wasn't missing something obvious...

[Michael DeHaan]

Alternatively, something like this:

vars:

   openais_enabled: "{% if enable_service_address is defined and enable_service_address %}yes{% else %}no{% endif %}

   openais_running: "{% if enable_service_address is defined and enable_service_address %}running{% else %}stopped{% endif %}

and in tasks:

- name: be sure openais is running and enabled

  service: name=openais state={{ openais_running }} enabled={{ openais_enabled }}

I'm not sure I really like that, as the conditional is a bit thick, though.

More so just sharing for completeness.

[Christian Thiemann]

I like to use the ternary operator in cases like these (not as "thick" as the conditionals):

vars:

  openais_enabled: "{{ 'yes' if enable_service_address is defined and enable_service_address else 'no' }}"

  openais_running: "{{ 'running' if enable_service_address is defined and enable_service_address else 'stopped' }}"

Or, to avoid variables and have the logic all in the task definition:

- name: be sure openais is running and enabled

  service:
    name: openais

    state: "{{ 'running' if enable_service_address is defined and enable_service_address else 'stopped' }}"

    enabled: "{{ 'yes' if enable_service_address is defined and enable_service_address else 'no' }}"

Cheers,
Christian