fix: allow multiple docs in one yaml

[mirosval]

I was trying to follow the Typed Resources Docs to create a definition for IPAddressPools and L2Advertisements from MetalLB.

I was unable to find a better source of their CRDs other than this one: https://github.com/metallb/metallb/blob/aa2fa5744e4bcd7ce5c44c8d3ba60c4fa360d303/config/manifests/metallb-native.yaml which seems to contain all of the CRDs in one file.

This resulted in the following error:

error: builder for '/nix/store/vs429dhh4hm5h0kn0lqg6dh2a35i8m19-metallb-jsonschema.json.drv' failed with exit code 1;
       last 24 log lines:
       > Running phase: unpackPhase
       > unpacking source archive /nix/store/l4hh20lihcm07gxkjq254fadxg9ky821-source
       > source root is source
       > Running phase: installPhase
       > Traceback (most recent call last):
       >   File "/nix/store/m9dgdsksa5myjzkc09r2wsaq7dv80nqd-crd2jsonschema.py", line 228, in <module>
       >     schema = generate_jsonschema(prefix, files, attr_name_overrides)
       >   File "/nix/store/m9dgdsksa5myjzkc09r2wsaq7dv80nqd-crd2jsonschema.py", line 51, in generate_jsonschema
       >     data = yaml.safe_load(f)
       >   File "/nix/store/q6hizrxhfjfhk63ji8dfmkd0k05zya6g-python3-3.13.5-env/lib/python3.13/site-packages/yaml/__init__.py", line 125, in safe_load
       >     return load(stream, SafeLoader)
       >   File "/nix/store/q6hizrxhfjfhk63ji8dfmkd0k05zya6g-python3-3.13.5-env/lib/python3.13/site-packages/yaml/__init__.py", line 81, in load
       >     return loader.get_single_data()
       >            ~~~~~~~~~~~~~~~~~~~~~~^^
       >   File "/nix/store/q6hizrxhfjfhk63ji8dfmkd0k05zya6g-python3-3.13.5-env/lib/python3.13/site-packages/yaml/constructor.py", line 49, in get_single_data
       >     node = self.get_single_node()
       >   File "/nix/store/q6hizrxhfjfhk63ji8dfmkd0k05zya6g-python3-3.13.5-env/lib/python3.13/site-packages/yaml/composer.py", line 41, in get_single_node
       >     raise ComposerError("expected a single document in the stream",
       >             document.start_mark, "but found another document",
       >             event.start_mark)
       > yaml.composer.ComposerError: expected a single document in the stream
       >   in "charts/metallb/charts/crds/templates/crds.yaml", line 1, column 1
       > but found another document
       >   in "charts/metallb/charts/crds/templates/crds.yaml", line 121, column 1

I've noticed that you're using pyyaml.safe_load(), so I've just converted that piece of code to use pyyaml.safe_load_all() instead and then iterate over the documents within the file.

However this caused another issue, as there is no real detection that we're looking at a CRD, so I've added a basic check for that as well.

The PR is just these 3 lines:

docs = yaml.safe_load_all(f)

for data in docs:
    if "spec" in data and "kind" in data and data["kind"] == "CustomResourceDefinition":

the rest is just indented to match.

With this change I was able to properly generate and use the MetalLB resources.

[arnarg]

Thank you for this contribution! It looks good but could you also add a unit test for this change in ./pkgs/generators/crd/test_crd2jsonschema.py? :)

[mirosval]

@arnarg Thank you for the review and an amazing project! I've added a test, LMK if there's anything else you'd like me to look at.

[arnarg]

Looks good! Thank you!