Is it possible to add new jinja2 filter?

[funbiscuit]

In my use case I want to generate configmap with config in yaml that is generated from variables in context.
For example, in my vars file I write this:

service:
  config:
    someVar: 12
    someDict:
      list:
        - 12
        - 13

And then in configmap manifest I add something like this:

apiVersion: v1
kind: ConfigMap
metadata:
  name: test-configmap
data:
  config.yaml: |
    {{ service.config|toyaml|indent(4) }}

But there is no filter toyaml in builtin filters of jinja2, so this doesn't work. There is a tojson filter, but target service supports only yamls.
So the question is, is it possible to add extra filter? Or maybe I'm missing some other solution. Or this can be done only inside go-jinja2 library (and then I can open an issue there). I can try to implement such filter and create a PR if this okay.

[funbiscuit]

There is also this plugin: jinja2-ansible-filter. So maybe it's possible to add that to go-jinja2 library and use to_nice_yaml filter. But it's GPL3 licensed so maybe that's not an option

[funbiscuit]

Oh, I've found to_yaml in docs, it seems to work as expected

[codablock]

Cool that you found it on your own. Btw, json is also valid yaml (google for "yaml superset of json"), so even if there wouldn't be a to_yaml filter, you could have just used tojson. to_yaml is just more convenient as it's pretty-printed by default and because you can combine it with other templating features.

[netthier]

to_json also has the advantage that it doesn't need special indentation. Consider

data:
  config.yaml: '{{ service.config | to_json }}'