Google Cloud Composer KubernetesPodOperator InvalidImage error - docker

Question

I am trying to run a docker image from private GCR using KubernetesPodOperator in Cloud Composer, but getting the following error:
ERROR: Pod launching failed : Pod took too long to start
I have tried the following till now:
At first I tried increasing the "startup_timeout_seconds" but it didn't help.
Looking at the Composer created GKE cluster logs gave me the following error:
Failed to apply default image tag "docker pull us.gcr.io/my-proj-name/myimage-
name:latest": couldn't parse image reference "docker pull us.gcr.io/my-proj-
name/myimage-name:latest": invalid reference format: InvalidImageName
I tried pulling the same docker image on my local machine from my private GCR and it worked fine, not sure where is the issue.
This link https://kubernetes.io/docs/concepts/containers/images/#specifying-imagepullsecrets-on-a-pod tells me that
"All pods in a cluster will have read access to images in this registry.
The kubelet will authenticate to GCR using the instance’s Google service account. The service
account on the instance will have a https://www.googleapis.com/auth/devstorage.read_only, so
it can pull from the project’s GCR, but not push"
which means the pod should be able to pull image from GCR. FYI, I am using a service account
to provision my composer env and it has sufficient permission to read from GCS bucket.
Also, I did the following steps to add secret :
gcloud container clusters get-credentials <cluster_name>
kubectl create secret generic gc-storage-rw-key --from-file=key.json=<path_to_serv_accnt_key>
secret_file = secret.Secret(
deploy_type='volume',
deploy_target='/tmp/secrets/google',
secret='gc-storage-rw-key',
key='<path of serv acct key file>.json')
Refer it as secrets=[secret_file] inside KubernetesPodOperator operator in DAG
I have added image_pull_policy='Always' in my DAG as well but not working...
For reference: my CircleCI config.yml contains following
- run: echo ${GOOGLE_AUTH} > ${HOME}/gcp-key.json
- run: docker build --rm=false -t us.gcr.io/${GCP_PROJECT}/${IMAGE_NAME}:latest .
- run: gcloud auth activate-service-account --key-file ${HOME}/gcp-key.json
- run: gcloud --quiet config set project ${GCP_PROJECT}
- run: gcloud docker -- push us.gcr.io/${GCP_PROJECT}/${IMAGE_NAME}:latest
Could anyone please guide me?