I have a k8s git runner deployment which should access a private registry. However access is always failing:

Waiting for pod default/runner-6f15beb6-project-3046-concurrent-0xswl6 to be running, status is Pending
ERROR: Job failed: image pull failed: rpc error: code = Unknown desc = Error response from daemon: Get https://docker-registry/v2/image: unknown: Authentication is required

I have created the secret:

kubectl create secret docker-private ...

kubectl describe secrets docker-private
Name:         docker-private
Namespace:    default
Labels:       <none>
Annotations:  <none>

Type:  kubernetes.io/dockerconfigjson

Data
====
.dockerconfigjson:  184 bytes

Use the secret in gitlab's values.yml:

runners:
  ...
  imagePullSecrets:
  - name: docker-private 

And have verified that its actually part of the gitlab release:

helm get sandbox | grep -C 5 docker

  imagePullSecrets:
  - name: docker-private

What else can be source of failed registry access?