to_json filter (sometimes) turns values into strings

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1

Hi all,

It seems like the to_json filter behaves differently depending on:

  • Whether it’s passed the result of a template call directly, or whether the result of the template call is placed into a fact first
  • Whether the template call actually does any substitutions or not
  • Whether I’m using ansible community <=v4.10.0 or >=5.0.1

I’m including a test playbook that illustrates the behavior below, along with the relevant portions of the output. I’m relatively new to Ansible, so wanted to check in here before submitting a bug report – this may be just a nuance I’m not grasping.

When I run the playbook using Ansible 4.10.0, to_json turns the value into a JSON string, if and only if it’s passed the result of a template call which does no substitutions. If the template has a variable in it, or if the result of the template call is stored in a fact before being sent to to_json, the JSON looks how I’d expect.

When using Ansible 5.0.1, the value is turned into a string whenever to_json is passed the result of a template call, regardless of whether the template has a variable in it or not.

There’s a lot of permutations here, and I’m not sure which, if any, of these behaviors are unexpected. Thanks in advance for any help!

  • John

Test playbook:

2

Apologies - just noticed that my test playbook had an error in it (was trying to simplify and clarify the test case and forgot to change the template file name in a couple places). It doesn’t change the behavior I’m seeing, but this is the corrected version: