DinD push image to GCR from GKE

[danielhstahl]

As a final step in my workflow I am trying to build an image and push it to a (private) GCR that exists in the same project as my GKE cluster.

For my other steps I simply use the "default" gcloud service account that has read/write permissions to the GCR. I don't have to specify anything in imagePullSecrets; it automatically "works".

However, for the DinD step I get "You don't have the needed permissions to perform this operation, and you may have invalid credentials.". I get this at the "FROM gcr.io/myprivaterepo" line, so it seems that the gcloud service account is not working in DinD. I've created a kubernetes service account that mirrors the gcloud account (as described in https://cloud.google.com/kubernetes-engine/docs/how-to/workload-identity#gcloud) but including this SA as a volume does not work either.

Anyone successfully gotten this to work?