Condition before lookup

[Daniel Schroeder]

Hello list,

I'm having a problem with adding a condition before a lookup plugin.

A simplified example that everyone can reproduce is this:

- debug: msg="This debug message should not be triggerd since some_dict is not defined"
  when: some_dict is defined
  with_dict: some_dict

That doesn't work because with_dict is processed before the condition is checked. That's not wrong, that's a good feature, because it enables you to do things like this:

- debug: msg="Only process item a"
  when: item == "a"
  with_items:
    - a
    - b

How could I solve my problem with having a condition before the task fails, because some_dict is not defined in my first example?

Not even an ignore_errors: yes helps in this case. I guess because it is a fatal error raised by the plugin and not simply a failed task.

TASK: [debug msg="This debug message should not be triggerd since some_dict is not defined"] ***
fatal: [test1.local] => with_dict expects a dict


FATAL: all hosts have already failed -- aborting

Thanks,

Daniel

[Daniel Schroeder]

OK, I found a workaround. My task actually is inside a role. Therefore I was able to define a default value for some_dict.

myRole/defaults/main.yml:

some_dict: {}

The condition still is ignored, but with no elements nothing is processed, obviously.

Is there another solution to this? If this task would not be inside a role (yes, I know you always should work with roles ;)) I wouldn't be able to define a default value.

Cheers,

Daniel

[Brian Coca]

conditionals are for tasks, not for lookups, these always get executed

[Daniel Schroeder]

Not really a solution for the problem, is it? ;)

Am Montag, 22. September 2014 12:44:54 UTC+2 schrieb Daniel Schroeder:

[Brian Coca]

actually the solution is what you already used or

with_dict: some_dict|default({})

[Daniel Schroeder]

Ah, great, didn't know you can use default in the yml itself. Only had been using it in jinja templates. Thanks, that works and is more elegant that creating the additional defaults file.

[Brian Coca]

"with_" fields are 'auto templated', you can use jinja2 in all fields
that are so

[Michael DeHaan]

For some further elucidation, it should be pointed out that the "when" gets evaluated for every step of the loop, which is why it can't be applied to decide whether to loop in the first place.

when: foo is defined and <insert conditional here on the loop item>

with_items: foo

Will work as a looping construct, if you don't want to the default trick.   

On Mon, Sep 22, 2014 at 9:42 AM, Brian Coca <bria...@gmail.com> wrote:

"with_" fields are 'auto templated', you can use jinja2 in all fields
that are so

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