[SOLVED] subPathExpr in Google Cloud Run

subPathExpr in Google Cloud Run

Requirement is to dynamically create a subdirectory based on pod uid and mount it inside the container.

env:
  - name: METADATA_UID
    valueFrom:
      fieldRef:
        fieldPath: metadata.uid

Since init containers are not supported in Google Cloud Run, we will have to achieve this by running a side car and wait in main container until the directory is created.

mkdir -p /shared_storage_root/POD_$METADATA_UID/logs/XYZ

and mount inside container

- name: log-efs
    mountPath: /home/app/logs
    subPathExpr: POD_$METADATA_UID/logs/XYZ

is subPathExpr feature supported by Google Cloud Run? I have seen post which suggests that we can apply a full k8s manifest generated by helm in Google Cloud Run, so does it mean it will be supported at runtime?

Solution

subPathExpr is not supported by Cloud Run. While you can use Helm to generate configs that are compatible with Cloud Run, not all Kubernetes configs are compatible with it.