instruction: Create a Dockerfile for configuration
output: ```dockerfile
  from within Pods.
  Docker config Secrets
  If you are creating a Secret to store credentials for accessing a container image registry,
  you must use one of the following type values for that Secret:
  
  kubernetes.io/dockercfg: store a serialized ~/.dockercfg which is the
  legacy format for configuring Docker command line. The Secret
  data field contains a .dockercfg key whose value is the content of a
  base64 encoded ~/.dockercfg file.
  kubernetes.io/dockerconfigjson: store a serialized JSON that follows the
  same format rules as the ~/.docker/config.json file, which is a new format
  for ~/.dockercfg. The Secret data field must contain a
  .dockerconfigjson key for which the value is the content of a base64
  encoded ~/.docker/config.json file.
  
  Below is an example for a kubernetes.io/dockercfg type of Secret:
  
  secret/dockercfg-secret.yaml
  
  apiVersion: v1
  kind: Secret
  metadata:
   name: secret-dockercfg
  type: kubernetes.io/dockercfg
  data:
   .dockercfg: |
   eyJhdXRocyI6eyJodHRwczovL2V4YW1wbGUvdjEvIjp7ImF1dGgiOiJvcGVuc2VzYW1lIn19fQo=
  
  Note:If you do not want to perform the base64 encoding, you can choose to use the
  stringData field instead.
  When you create Docker config Secrets using a manifest, the API
  server checks whether the expected key exists in the data field, and
  it verifies if the value provided can be parsed as a valid JSON. The API
  server doesn't validate if the JSON actually is a Docker config file.
  You can also use kubectl to create a Secret for accessing a container
  registry, such as when you don't have a Docker configuration file:
  kubectl create secret docker-registry secret-tiger-docker \
   --docker-email=tiger@acme.example \
   --docker-username=tiger \
   --docker-password=pass1234 \
   --docker-server=my-registry.example:5000
  This command creates a Secret of type kubernetes.io/dockerconfigjson.
  Retrieve the .data.dockerconfigjson field
  ```