YAML line breaks (newlines) when performing lookups of files or templates

[Dmitriy Panteleyev]

I've been banging my head against this for two days.  Maybe I'm missing something.  When fetching a YAML file or template with lookup function, all the newlines are not preserved, but converted to '\n'.  This does not happen for other file types (like json).  Is this the expected behavior?  Is there a way around it?

Examples follow:

given file 'test.yml'

json:

  - rigid

  - better for data interchange

yaml:

  - slim and flexible

  - better for configuration

object:

  key: value

  array:

    - null_value:

    - boolean: true

    - integer: 1

paragraph: >

   Blank lines denote

   paragraph breaks

content: |-

   Or we

   can auto

   convert line breaks

   to save space

printing out a lookup: 

- debug:
    msg: "{{ lookup('file', test.yml') }}"

 

results in:

ok: [localhost] => {
    "msg": "json:\n  - rigid\n  - better for data interchange\nyaml:\n  - slim and flexible\n  - better for configuration\nobject:\n  key: value\n  array:\n    - null_value:\n    - boolean: true\n    - integer: 1\nparagraph: >\n   Blank lines denote\n\n   paragraph breaks\ncontent: |-\n   Or we\n   can auto\n   convert line breaks\n   to save space"
}

On the other hand, given the same info in JSON ('test.json'):

{

  "json": [

    "rigid",

    "better for data interchange"

  ],

  "yaml": [

    "slim and flexible",

    "better for configuration"

  ],

  "object": {

    "key": "value",

    "array": [

      {

        "null_value": null

      },

      {

        "boolean": true

      },

      {

        "integer": 1

      }

    ]

  },

  "paragraph": "Blank lines denote\nparagraph breaks\n",

  "content": "Or we\ncan auto\nconvert line breaks\nto save space"

}

and printing out the same lookup: 

- debug:
    msg: "{{ lookup('file', test.json') }}"

 

results in:

ok: [localhost] => {
    "msg": {
        "content": "Or we\ncan auto\nconvert line breaks\nto save space", 
        "json": [
            "rigid", 
            "better for data interchange"
        ], 
        "object": {
            "array": [
                {
                    "null_value": null
                }, 
                {
                    "boolean": true
                }, 
                {
                    "integer": 1
                }
            ], 
            "key": "value"
        }, 
        "paragraph": "Blank lines denote\nparagraph breaks\n", 
        "yaml": [
            "slim and flexible", 
            "better for configuration"
        ]
    }
}

[Kai Stian Olstad]

On Saturday, 13 October 2018 18.37.22 CEST Dmitriy Panteleyev wrote:
> I've been banging my head against this for two days. Maybe I'm missing
> something. When fetching a YAML file or template with lookup function, all
> the newlines are not preserved, but converted to '\n'.

They are not converted, this is just how the default callback plugin chooses to show the content in the debug module.

> This does not
> happen for other file types (like json). Is this the expected behavior?

Yes

> Is there a way around it?

Ansible is not a reporting tool, so if that is what you are looking for you probably need some other tool.
That being said you have many callback plugins to choose[1] and if non of them suites your need to can always create you own.


[1] https://docs.ansible.com/ansible/2.7/plugins/callback.html#plugin-list

--
Kai Stian Olstad

[Dmitriy Panteleyev]

Thanks for the insight.

Turns out the problem is in one of Ansible's modules, not the formatting of the lookup result.