Which command creates a secret regtoken from a dockerconfigjson file with the proper type for use by Kubernetes?

Which command creates a secret regtoken from a dockerconfigjson file with the proper type for use by Kubernetes?

• A. oc create secret generic regtoken --from-file .dockerconfigjson=${XDG_RUNTIME_DIR}/containers/auth.json --type kubernetes.io/dockerconfigjson
• B. oc create secret generic regtoken --from-file .dockerconfigjson=${XDG_RUNTIME_DIR}/containers/auth.json --type kubeconfigjson
• C. oc create secret generic regtoken --from-file dockerconfigjson=${XDG_RUNTIME_DIR}/containers/auth.json --type kubernetes.io/dockerconfigjson
• D. oc create secret generic regtoken --from-file .dockerconfigjson=${XDG_RUNTIME_DIR}/containers/auth.json --type kubernetes.io/dockersecret

Answer: (A)

The key idea is that Kubernetes expects a secret of type kubernetes.io/dockerconfigjson to hold a Docker config in a data field named .dockerconfigjson. The correct command maps the local file to that exact key and sets the proper type, producing a secret that Kubernetes can use as an image pull secret. Specifically, it uses --from-file with .dockerconfigjson=path/to/file and --type kubernetes.io/dockerconfigjson, which creates the data entry .dockerconfigjson containing the Docker config JSON. The other options fail because they either use an incorrect secret type or omit the required leading dot in the data key, which would create a data field named dockerconfigjson instead of .dockerconfigjson and Kubernetes wouldn’t recognize it as a Docker config secret.

The key idea is that Kubernetes expects a secret of type kubernetes.io/dockerconfigjson to hold a Docker config in a data field named .dockerconfigjson. The correct command maps the local file to that exact key and sets the proper type, producing a secret that Kubernetes can use as an image pull secret. Specifically, it uses --from-file with .dockerconfigjson=path/to/file and --type kubernetes.io/dockerconfigjson, which creates the data entry .dockerconfigjson containing the Docker config JSON. The other options fail because they either use an incorrect secret type or omit the required leading dot in the data key, which would create a data field named dockerconfigjson instead of .dockerconfigjson and Kubernetes wouldn’t recognize it as a Docker config secret.