ConfigMap data keys with leading underscore get removed

[felixscheinost]

I need to populate a ConfigMap with a key that is starting with a underscore but the resulting ConfigMap doesn't contain the expected keys.

Example:

  kubernetes.resources.configMaps.foo.data._FOO = "_bar";

It seems this like is the culprit:

kubenix/modules/k8s.nix

Line 21 in e4d0365

then mapAttrs (_n: moduleToAttrs) (filterAttrs (n: v: v != null && !(hasPrefix "_" n)) value)

Do you know what the purpose of this filter is?

I tried going back the git history but I reached cbf84e2 (first commit).

[adrian-gierakowski]

possible reasons:

• kubernetes resource names are not allowed to start with _, and
• author used _ for resources\props which were used internally but where not meant to be part of generated yaml

ConfigMap data is most likely collateral damage

I'll test removal of this on my work configs to see if it causes any issues.