support environment variable expansion in log config

[wasim-nihal]

we have a use case where we spin up 3 different kiwigrid k8s-sidecars. And each of this sidecar has its own log config mounted as a config map. It would be better if there is a feature in kiwigrid-k8s sidecar to expand environment variables and populate the log config at the startup. This would enable users to have only only log config for multiple k8s sidecars and the values can be configurable via environment variables.

Example:
The expansion can happen based on a specific placeholder in the log config (To instance $(<some_env_variable>).

The user can configure the log config in the below way:

version: 1
disable_existing_loggers: false

root:
    level: $(LOG_LEVEL)
    handlers: [console]

And in different sidecars, the value of the environment variable can be different according to needs.

Note: This feature will not be limited to LOG_LEVEL. It shall be generic enough to look up any environment variable enclosed within the placeholder $().

[ChristianGeie]

Hi @wasim-nihal thx for contributing. Unfortunately, I only now had time to look at your PR. Looks good to me. Can you add a scenario to the existing tests that represents your added functionality?

[wasim-nihal]

Hi @wasim-nihal thx for contributing. Unfortunately, I only now had time to look at your PR. Looks good to me. Can you add a scenario to the existing tests that represents your added functionality?

Hello @ChristianGeie , thanks for taking a look. I have added the test for this feature. Could you please review this? #344

[github-actions]

This issue has been automatically marked as stale because it has not had any activity in the last 60 days. Thank you for your contributions.

[wasim-nihal]

This issue has been automatically marked as stale because it has not had any activity in the last 60 days. Thank you for your contributions.

commenting to remove stale marker