Jinja non rendering blocks adds whitespaces to next rendering block

Question

I have the following import on a jinja template that is rendered by ansible:

      labels:
      {% set name = 'jellyfin' %}
      {% set port = '8096' %}
      {% filter indent(width=8, first=True) %}
      {% include './labels.yml.jinja' %}
      {% endfilter %}

As you can see, there are some non rendering blocks to set some local variables and stuff. When the template is rendered by ansible, the first row of the template is shifted by the same amount of spaces that the non rendering blocks sum + 2 (32 in this case = 5 blocks with 6 spaces + 2).

For example:

      labels:
                                # this are the labels, fools
        - "traefik.enable=true"
        - "traefik.backend=jellyfin"

I can remove the indentation of ALL the {% %} blocks, and then it will work properly, but looks ugly and off place.

Even if I add a minus sign to remove whitespaces to the non rendering blocks like this:

      {% set name = 'jellyfin' -%}
      {% set port = '8096' -%}
      {% filter indent(width=8, first=True) -%}
      {% include './labels.yml.jinja' -%}
      {% endfilter -%}

The first line is still shifted (albeit much less)

How can I fix this?

Answer 1

I just had to add #jinja2: lstrip_blocks: "True" to the very top of the importing template, and that did the trick.

I gathered that information from this article, explaining my exact problem and showing a solution: https://radeksprta.eu/posts/control-whitespace-in-ansible-templates/

But I have to say that the default behaviour is very confusing.