instruction: Create a Kubernetes ServiceAccount configuration with best practices
output: ```dockerfile
  from that Secret.Note:If you view the ServiceAccount using:kubectl get serviceaccount build-robot -o yamlYou can't see the build-robot-secret Secret in the ServiceAccount API objects
  .secrets field
  because that field is only populated with auto-generated Secrets.Add ImagePullSecrets to a service accountFirst, create an imagePullSecret.
  Next, verify it has been created. For example:Create an imagePullSecret, as described in
  Specifying ImagePullSecrets on a Pod.kubectl create secret docker-registry myregistrykey --docker-server=<registry name> \
   --docker-username=DUMMY_USERNAME --docker-password=DUMMY_DOCKER_PASSWORD \
   --docker-email=DUMMY_DOCKER_EMAIL
  Verify it has been created.kubectl get secrets myregistrykey
  The output is similar to this:NAME TYPE DATA AGE
  myregistrykey   kubernetes.io/.dockerconfigjson   1       1d
  Add image pull secret to service accountNext, modify the default service account for the namespace to use this Secret as an imagePullSecret.kubectl patch serviceaccount default -p '{"imagePullSecrets": [{"name": "myregistrykey"}]}'
  You can achieve the same outcome by editing the object manually:kubectl edit serviceaccount/default
  The output of the sa.yaml file is similar to this:Your selected text editor will open with a configuration looking something like this:apiVersion: v1
  kind: ServiceAccount
  metadata:
   creationTimestamp: 2021-07-07T22:02:39Z
   name: default
   namespace: default
   resourceVersion: "243024"
   uid: 052fb0f4-3d50-11e5-b066-42010af0d7b6
  Using your editor, delete the line with key resourceVersion, add lines for
  imagePullSecrets: and save it. Leave the uid value set the same as you found it.After you made those changes, the edited ServiceAccount looks something like this:apiVersion: v1
  kind: ServiceAccount
  metadata:
   creationTimestamp: 2021-07-07T22:02:39Z
   name: default
   namespace: default
   uid: 052fb0f4-3d50-11e5-b066-42010af0d7b6
  imagePullSecrets:
   - name: myregistrykey
  Verify that imagePullSecrets are set for new PodsNow, when a new Pod is created in the current namespace and using the default
  ServiceAccount, the new Pod has its spec.imagePullSecrets field set automatically:kubectl run nginx --image=<registry name>/nginx --restart=Never
  kubectl get pod nginx -o=jsonpath='{.spec.imagePullSecrets[0].name}{"\n"}'
  The output is:myregistrykey
  ServiceAccount token volume projectionFEATURE STATE:
  Kubernetes v1.20 [stable]Note:To enable and use token request projection, you must specify each of the following
  command line arguments to kube-apiserver:--service-account-issuerdefines the Identifier of the service account token issuer. You can specify the
  --service-account-issuer argument multiple times, this can be useful to enable
  a non-disruptive change of the issuer. When this flag is specified multiple times,
  the first is used to generate tokens and all are used to determine which issuers
  are accepted. You must be running Kubernetes v1.22 or later to be able to specify
  --service-account-issuer multiple times.--service-account-key-filespecifies the path to a file containing PEM-encoded X.509 private or public keys
  (RSA or ECDSA), used to verify ServiceAccount tokens. The specified file can contain
  multiple keys, and the flag can be specified multiple times with different files.
  If specified multiple times, tokens signed by any of the specified keys are considered
  valid by the Kubernetes API server.--service-account-signing-key-filespecifies the path to a file that contains the current private key of the service
  account token issuer. The issuer signs issued ID tokens with this private key.--api-audiences (can be omitted)defines audiences for ServiceAccount tokens. The service account token authenticator
  validates that tokens used against the API are bound to at least one of these audiences.
  If api-audiences is specified multiple times, tokens for any of the specified audiences
  are considered valid by the Kubernetes API server. If you specify the --service-account-issuer
  command line argument but you don't set --api-audiences, the control plane defaults to
  a single element audience list that contains only the issuer URL.The kubelet can also project a ServiceAccount token into a Pod. You can
  specify desired properties of the token, such as the audience and the validity
  duration. These properties are not configurable on the default ServiceAccount
  token. The token will also become invalid against the API when either the Pod
  or the ServiceAccount is deleted.You can configure this behavior for the spec of a Pod using a
  projected volume type called
  ServiceAccountToken.The token
  ```