The OpenShift Container Platform master includes a built-in OAuth server. Developers and administrators obtain OAuth access tokens to authenticate themselves to the API.

As an administrator, you can configure OAuth to specify an identity provider after you install your cluster.

About identity providers in OpenShift Container Platform

By default, only a kubeadmin user exists on your cluster. To specify an identity provider, you must create a Custom Resource (CR) that describes that identity provider and add it to the cluster.

OpenShift Container Platform user names containing /, :, and % are not supported.

Supported identity providers

You can configure the following types of identity providers:

Identity provider Description

Configure the htpasswd identity provider to validate user names and passwords against a flat file generated using htpasswd.

Configure the keystone identity provider to integrate your OpenShift Container Platform cluster with Keystone to enable shared authentication with an OpenStack Keystone v3 server configured to store users in an internal database.

Configure the ldap identity provider to validate user names and passwords against an LDAPv3 server, using simple bind authentication.

Configure a basic-authentication identity provider for users to log in to OpenShift Container Platform with credentials validated against a remote identity provider. Basic authentication is a generic backend integration mechanism.

Configure a request-header identity provider to identify users from request header values, such as X-Remote-User. It is typically used in combination with an authenticating proxy, which sets the request header value.

Configure a github identity provider to validate user names and passwords against GitHub or GitHub Enterprise’s OAuth authentication server.

Configure a gitlab identity provider to use GitLab.com or any other GitLab instance as an identity provider.

Configure a google identity provider using Google’s OpenID Connect integration.

Configure an oidc identity provider to integrate with an OpenID Connect identity provider using an Authorization Code Flow.

Once an identity provider has been defined, you can use RBAC to define and apply permissions.

Removing the kubeadmin user

After you define an identity provider and create a new cluster-admin user, you can remove the kubeadmin to improve cluster security.

If you follow this procedure before another user is a cluster-admin, then OpenShift Container Platform must be reinstalled. It is not possible to undo this command.

Prerequisites
  • You must have configured at least one identity provider.

  • You must have added the cluster-admin role to a user.

  • You must be logged in as an administrator.

Procedure
  • Remove the kubeadmin secrets:

    $ oc delete secrets kubeadmin -n kube-system

Identity provider parameters

The following parameters are common to all identity providers:

Parameter Description

name

The provider name is prefixed to provider user names to form an identity name.

mappingMethod

Defines how new identities are mapped to users when they log in. Enter one of the following values:

claim

The default value. Provisions a user with the identity’s preferred user name. Fails if a user with that user name is already mapped to another identity.

lookup

Looks up an existing identity, user identity mapping, and user, but does not automatically provision users or identities. This allows cluster administrators to set up identities and users manually, or using an external process. Using this method requires you to manually provision users.

generate

Provisions a user with the identity’s preferred user name. If a user with the preferred user name is already mapped to an existing identity, a unique user name is generated. For example, myuser2. This method should not be used in combination with external processes that require exact matches between OpenShift Container Platform user names and identity provider user names, such as LDAP group sync.

add

Provisions a user with the identity’s preferred user name. If a user with that user name already exists, the identity is mapped to the existing user, adding to any existing identity mappings for the user. Required when multiple identity providers are configured that identify the same set of users and map to the same user names.

When adding or changing identity providers, you can map identities from the new provider to existing users by setting the mappingMethod parameter to add.

Sample identity provider CR

The following Custom Resource (CR) shows the parameters and default values that you use to configure an identity provider. This example uses the HTPasswd identity provider.

Sample identity provider CR
apiVersion: config.openshift.io/v1
kind: OAuth
metadata:
  name: cluster
spec:
  identityProviders:
  - name: my_identity_provider (1)
    mappingMethod: claim (2)
    type: HTPasswd
    htpasswd:
      fileData:
        name: htpass-secret (3)
1 This provider name is prefixed to provider user names to form an identity name.
2 Controls how mappings are established between this provider’s identities and user objects.
3 An existing secret containing a file generated using htpasswd.