feat: add airflow.defaultContainerSecurityContext value

[zartstrom]

Signed-off-by: Philipp Hitzler philipp.hitzler@idealo.de

What issues does your PR fix?

• fixes add airflow.defaultContainerSecurityContext value  #578 (except for Postgres and Redis)

What does your PR do?

This PR adds the following values:

• airflow.defaultContainerSecurityContext (default: {})
  • Sets the Container SecurityContext of all airflow containers (including PGBouncer)
  • Does not set runAsUser and runAsGroup (those are set per-image with the *.image.uid and *.image.gid values)
  • Will NOT set Container SecurityContext of embedded Postgres or Redis due to still using the old charts:
    • stop using embedded stable/postgres chart #303
    • stop using embedded stable/redis chart #304

@thesuperzapper all code is taken from your #578 (comment)

Checklist

For all Pull Requests

• Commits are signed off
• Commits have semantic messages
• Documentation updated
• Passes ct linting

For releasing ONLY

• Chart.yaml version bumped
• CHANGELOG.md updated

[stale]

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It will be closed in 7 days if no further activity occurs.

Thank you for your contributions.

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[kshekhar-outra]

seems like a good feature to use, will this approved?

[thesuperzapper]

@zartstrom sorry about the extreme delay on this, but thanks for the PR.

I have pushed a small cleanup in abe66e4.

But its otherwise good to go, and should be in version 8.9.0 of the chart!