Configuring a GitLab identity provider - Configuring identity providers | Authentication and authorization

Identity providers in OKD
About GitLab authentication
Creating the secret
Creating a ConfigMap
Sample GitLab custom resource
Adding an identity provider to your cluster
Additional resources

Configure the gitlab identity provider so users can log in to OKD with GitLab account credentials through OAuth.

Identity providers in OKD

You can configure identity providers by creating a custom resource (CR) that describes the provider and adding it to the cluster. Identity providers enable user authentication in OKD beyond the default kubeadmin user.

OKD usernames containing /, :, and % are not supported.

About GitLab authentication

Review GitLab authentication options for OKD. Use this integration when you want users to log in with GitLab account credentials through OAuth or OpenID Connect.

If you use GitLab version 7.7.0 to 11.0, you connect using OAuth integration. If you use GitLab version 11.1 or later, you can use OpenID Connect (OIDC) to connect instead of OAuth.

Additional resources

Creating the secret

Create a Secret object in the openshift-config namespace to store the client secret for your identity provider. The identity provider custom resource (CR) references this secret during configuration.

Procedure

Create a Secret object containing the client secret by running the following command:

$ oc create secret generic <secret_name> --from-literal=clientSecret=<secret> -n openshift-config

Optional: Apply the following YAML to create the secret:

apiVersion: v1
kind: Secret
metadata:
  name: <secret_name>
  namespace: openshift-config
type: Opaque
data:
  clientSecret: <base64_encoded_client_secret>

Create a Secret object from a file by running the following command:

$ oc create secret generic <secret_name> --from-file=<path_to_file> -n openshift-config

Creating a ConfigMap

Create a ConfigMap object in the openshift-config namespace that contains the certificate authority bundle for the identity provider. OKD uses this bundle to validate Transport Layer Security (TLS) connections to the identity provider.

Procedure

Define an OKD ConfigMap object containing the CA by running the following command:

$ oc create configmap ca-config-map --from-file=ca.crt=/path/to/ca -n openshift-config

Optional: Apply the following YAML to create the config map:

apiVersion: v1
kind: ConfigMap
metadata:
  name: ca-config-map
  namespace: openshift-config
data:
  ca.crt: |
    <CA_certificate_PEM>

The CA must be stored in the ca.crt key of the ConfigMap object.

Sample GitLab custom resource

Review the sample GitLab OAuth custom resource (CR) to understand provider parameters and acceptable values before you configure the identity provider in your cluster.

apiVersion: config.openshift.io/v1
kind: OAuth
metadata:
  name: cluster
spec:
  identityProviders:
  - name: gitlabidp
    mappingMethod: claim
    type: GitLab
    gitlab:
      clientID: {...}
      clientSecret:
        name: gitlab-secret
      url: https://gitlab.com
      ca:
        name: ca-config-map

where:

spec.identityProviders.name: Specifies that the provider name is prefixed to the GitLab numeric user ID to form an identity name. It is also used to build the callback URL.
spec.identityProviders.mappingMethod: Specifies how mappings are established between identities from this provider and User objects.
spec.identityProviders.gitlab.clientID: Specifies the client ID of a registered GitLab OAuth application. The application must be configured with a callback URL of https://oauth-openshift.apps.<cluster-name>.<cluster-domain>/oauth2callback/<idp-provider-name>.
spec.identityProviders.gitlab.clientSecret: Specifies a reference to an OKD Secret object containing the client secret issued by GitLab.
spec.identityProviders.gitlab.url: Specifies the host URL of a GitLab provider. This could either be https://gitlab.com/ or any other self-hosted instance of GitLab.
spec.identityProviders.gitlab.ca: Specifies a reference to an OKD ConfigMap object containing the PEM-encoded certificate authority bundle to use in validating server certificates for the configured URL. This value is optional.

Additional resources

Identity provider parameters

Adding an identity provider to your cluster

Apply the identity provider custom resource (CR) to your cluster after you define it. With this configuration, you can authenticate with the configured identity provider.

Prerequisites

You have access to a OKD cluster.
You have created the CR for your identity providers.
You are logged in as an administrator.

Procedure

Apply the defined CR by running the following command:

$ oc apply -f </path/to/CR>

If a CR does not exist, oc apply creates a new CR and might trigger the following warning: Warning: oc apply should be used on resources created by either oc create --save-config or oc apply. In this case you can safely ignore this warning.

Log in to the cluster as a user from your identity provider, entering the password when prompted.
```
$ oc login -u <username>
```
Confirm that the user logged in successfully and that the username displays by running the following command:
```
$ oc whoami
```

Additional resources

GitLab.com