Context based variable substitution in Ansible 2.0

[Christian Kaps]

I have a role which contains tasks that are executed based on a variable set in a playbook. In my case I have a provisioning playbook and a configuration playbook. Both share a role named `ebs_single`. In this role I've tasks which should be executed only in the provisioning step and some other tasks which should be executed in the configuration step. 

- name: Some provisioning task
  ...
  with_items: "{{ ec2.instances }}"
  register: ec2_volumes
  when: ebs_single_provisioning

- name: Some configuration task
  ...
  when: ebs_single_configuration

Prior to 2.0 this wasn't an issue, because I've used a bare variable in `with_items`:

with_items: ec2.instances

But now if I try to fix the deprecation warning, I get an error that the variable `ec2` is not found.

I'm not sure if this is an issue or if it's by design. But how can I use such a concept with Ansible 2.0?

I've tried to default the variable if it's not set. But this doesn't work. I think also this would be the wrong way to fix this issue, because in the provisioning step an error should be thrown if the variable doesn't exists.

with_items: "{{ ec2.instances|default(omit) }}"

Any suggestions?

Best regards,

Christian

[Christian Kaps]

Sorry, I forgot to mention that it fails in the configuration step, because the e2c variable is only set in the provisioning step.

Anyway, I got it working with the include statement.

- include: provisioning.yml
  when: ebs_single_provisioning

- include: configuration.yml
  when: ebs_single_configuration

Best regards,

Christian

[Brian Coca]

Return an empty list and the task will be skipped, the `when` executes for EACH item, this 'worked' in 1.9 as the error was ignored and task skipped, not because the `when` was evaluated. 

You can remove the `when` on the second task, for the `with_` do this:

`with_items: "{{ (ec2|default({})).instances|default([]) }}"`

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Brian Coca