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Understanding and creating service accounts | Authentication and authorization | OpenShift Container Platform 4.8
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Service accounts overview

A service account is an OpenShift Container Platform account that allows a component to directly access the API. Service accounts are API objects that exist within each project. Service accounts provide a flexible way to control API access without sharing a regular user’s credentials.

When you use the OpenShift Container Platform CLI or web console, your API token authenticates you to the API. You can associate a component with a service account so that they can access the API without using a regular user’s credentials. For example, service accounts can allow:

  • Replication controllers to make API calls to create or delete pods.

  • Applications inside containers to make API calls for discovery purposes.

  • External applications to make API calls for monitoring or integration purposes.

Each service account’s user name is derived from its project and name:

system:serviceaccount:<project>:<name>

Every service account is also a member of two groups:

Group Description

system:serviceaccounts

Includes all service accounts in the system.

system:serviceaccounts:<project>

Includes all service accounts in the specified project.

Each service account automatically contains two secrets:

  • An API token

  • Credentials for the OpenShift Container Registry

The generated API token and registry credentials do not expire, but you can revoke them by deleting the secret. When you delete the secret, a new one is automatically generated to take its place.

Creating service accounts

You can create a service account in a project and grant it permissions by binding it to a role.

Procedure
  1. Optional: To view the service accounts in the current project:

    $ oc get sa
    Example output
    NAME       secrets   AGE
    builder    2         2d
    default    2         2d
    deployer   2         2d
  2. To create a new service account in the current project:

    $ oc create sa <service_account_name> (1)
    1 To create a service account in a different project, specify -n <project_name>.
    Example output
    serviceaccount "robot" created

    You can alternatively apply the following YAML to create the service account:

    apiVersion: v1
    kind: ServiceAccount
    metadata:
      name: <service_account_name>
      namespace: <current_project>
  3. Optional: View the secrets for the service account:

    $ oc describe sa robot
    Example output
    Name:		robot
    Namespace:	project1
    Labels:		<none>
    Annotations:	<none>
    
    Image pull secrets:	robot-dockercfg-qzbhb
    
    Mountable secrets: 	robot-token-f4khf
                       	robot-dockercfg-qzbhb
    
    Tokens:            	robot-token-f4khf
                       	robot-token-z8h44

Examples of granting roles to service accounts

You can grant roles to service accounts in the same way that you grant roles to a regular user account.

  • You can modify the service accounts for the current project. For example, to add the view role to the robot service account in the top-secret project:

    $ oc policy add-role-to-user view system:serviceaccount:top-secret:robot

    You can alternatively apply the following YAML to add the role:

    apiVersion: rbac.authorization.k8s.io/v1
    kind: RoleBinding
    metadata:
      name: view
      namespace: top-secret
    roleRef:
      apiGroup: rbac.authorization.k8s.io
      kind: ClusterRole
      name: view
    subjects:
    - kind: ServiceAccount
      name: robot
      namespace: top-secret
  • You can also grant access to a specific service account in a project. For example, from the project to which the service account belongs, use the -z flag and specify the <service_account_name>

    $ oc policy add-role-to-user <role_name> -z <service_account_name>

    If you want to grant access to a specific service account in a project, use the -z flag. Using this flag helps prevent typos and ensures that access is granted to only the specified service account.

    You can alternatively apply the following YAML to add the role:

    apiVersion: rbac.authorization.k8s.io/v1
    kind: RoleBinding
    metadata:
      name: <rolebinding_name>
      namespace: <current_project_name>
    roleRef:
      apiGroup: rbac.authorization.k8s.io
      kind: ClusterRole
      name: <role_name>
    subjects:
    - kind: ServiceAccount
      name: <service_account_name>
      namespace: <current_project_name>
  • To modify a different namespace, you can use the -n option to indicate the project namespace it applies to, as shown in the following examples.

    • For example, to allow all service accounts in all projects to view resources in the my-project project:

      $ oc policy add-role-to-group view system:serviceaccounts -n my-project

      You can alternatively apply the following YAML to add the role:

      apiVersion: rbac.authorization.k8s.io/v1
      kind: RoleBinding
      metadata:
        name: view
        namespace: my-project
      roleRef:
        apiGroup: rbac.authorization.k8s.io
        kind: ClusterRole
        name: view
      subjects:
      - apiGroup: rbac.authorization.k8s.io
        kind: Group
        name: system:serviceaccounts
    • To allow all service accounts in the managers project to edit resources in the my-project project:

      $ oc policy add-role-to-group edit system:serviceaccounts:managers -n my-project

      You can alternatively apply the following YAML to add the role:

      apiVersion: rbac.authorization.k8s.io/v1
      kind: RoleBinding
      metadata:
        name: edit
        namespace: my-project
      roleRef:
        apiGroup: rbac.authorization.k8s.io
        kind: ClusterRole
        name: edit
      subjects:
      - apiGroup: rbac.authorization.k8s.io
        kind: Group
        name: system:serviceaccounts:managers