Add common volumes and volumeMounts

[chainlink]

Why are these changes needed?

This allows for setting common volumes and volumeMounts between the head and workers pods

Extends: #1932

Related issue number

Checks

• I've made sure the tests are passing.
• Testing Strategy
  • Unit tests
  • Manual tests
  • This PR is not tested :(

[chainlink]

@kevin85421 @Yicheng-Lu-llll Would you mind reviewing this one as well?

[kevin85421]

Hi @chainlink, thank you for the PR! I discussed this with @morhidi yesterday. We may decide to expose a common podTemplate instead of exposing fields one by one. Exposing fields one by one may make the Helm chart hard to maintain. I will not review the PR until we finalize the way that we plan to proceed.

[chainlink]

Sounds like a great feature! Just to confirm my understanding, that would get built in at the operator level instead of the helm chart, correct?

[morhidi]

Can this be done at helm level, without changing the CRD? That would be ideal.

[kevin85421]

It is better not to expose it at the CRD level. Etcd has a limitation on CRD size, and KubeRay CRDs are large, so I am very careful when adding something as significant as a new podTemplate to the CRD.