Authentication and Authorization with Keycloak

Load users and groups from Keycloak, enabling use of multiple authentication providers to be applied to Backstage entities.

NPM

Keycloak backend plugin for Backstage

The Keycloak backend plugin integrates Keycloak into Backstage.

Capabilities​

The Keycloak backend plugin has the following capabilities:

• Synchronization of Keycloak users in a realm
• Synchronization of Keycloak groups and their users in a realm

For administrators​

Installation​

Install the Backstage package into the backend. When not integrating with a published package, clone the repository locally and add the Backstage as follows:

yarn workspace backend add @janus-idp/backstage-plugin-keycloak-backend

Configuration​

1. Add the following configuration to the app-config.yaml file:

   app-config.yaml

   catalog:
     providers:
       keycloakOrg:
         default:
           baseUrl: https://<keycloak_host>/auth
           loginRealm: ${KEYCLOAK_REALM}
           realm: ${KEYCLOAK_REALM}
           clientId: ${KEYCLOAK_CLIENTID}
           clientSecret: ${KEYCLOAK_CLIENTSECRET}
   

2. Register the plugin in the packages/backend/src/plugins/catalog.ts file. You can also configure a schedule in this step. However, there are possible ways of configuration, such as:

   1. Configure a schedule inside the app-config.yaml file:

      app-config.yaml

      catalog:
        providers:
          keycloakOrg:
            default:
              # ...
              schedule: # optional; same options as in TaskScheduleDefinition
                # supports cron, ISO duration, "human duration" as used in code
                frequency: { minutes: 1 }
                # supports ISO duration, "human duration" as used in code
                timeout: { minutes: 1 }
                initialDelay: { seconds: 15 }
      

      Then use the configured scheduler by adding the following to the packages/backend/src/plugins/catalog.ts:

      packages/backend/src/plugins/catalog.ts

      import { KeycloakOrgEntityProvider } from '@janus-idp/backstage-plugin-keycloak-backend';
      
      
      export default async function createPlugin(
        env: PluginEnvironment,
      ): Promise<Router> {
        const builder = await CatalogBuilder.create(env);
      
        /* ... other processors and/or providers ... */
        builder.addEntityProvider(
          KeycloakOrgEntityProvider.fromConfig(env.config, {
            id: 'development',
            logger: env.logger,
            scheduler: env.scheduler,
          }),
        );
      
        const { processingEngine, router } = await builder.build();
        await processingEngine.start();
        return router;
      }
      

      ---

      NOTE

      If you have made any changes to the schedule in the app-config.yaml file, then restart to apply the changes.

      ---

   2. Add a schedule directly inside the packages/backend/src/plugins/catalog.ts file as follows:

      packages/backend/src/plugins/catalog.ts

      import { KeycloakOrgEntityProvider } from '@janus-idp/backstage-plugin-keycloak-backend';
      
      
      export default async function createPlugin(
        env: PluginEnvironment,
      ): Promise<Router> {
        const builder = await CatalogBuilder.create(env);
      
        /* ... other processors and/or providers ... */
        builder.addEntityProvider(
          KeycloakOrgEntityProvider.fromConfig(env.config, {
            id: 'development',
            logger: env.logger,
            schedule: env.scheduler.createScheduledTaskRunner({
              frequency: { minutes: 1 },
              timeout: { minutes: 1 },
              initialDelay: { seconds: 15 },
            }),
          }),
        );
      
        const { processingEngine, router } = await builder.build();
        await processingEngine.start();
        return router;
      }
      

   ---

   NOTE

   If both the schedule (hard-coded schedule) and scheduler (app-config.yaml schedule) option are provided in the packages/backend/src/plugins/catalog.ts, the scheduler option takes precedence. However, if the schedule inside the app-config.yaml file is not configured, then the schedule option is used.

   ---

3. Optional: override the default Keycloak query parameters. Configure the parameters inside the app-config.yaml file:

   app-config.yaml

   catalog:
     providers:
       keycloakOrg:
         default:
           # ...
           userQuerySize: 500 # Optional
           groupQuerySize: 250 # Optional
   

4. Optional: provide a transformer function for user/group to mutate the entity before their ingestion into catalog. Extend packages/backend/src/plugins/catalog.ts with custom userTransformer and groupTransformer functions:

   packages/backend/src/plugins/catalog.ts

   import {
     GroupTransformer,
     UserTransformer,
   } from '@janus-idp/backstage-plugin-keycloak-backend';
   
   
   // Suffix user entity name with realm name
   const userTransformer: UserTransformer = async (
     entity,
     user,
     realm,
     groups,
   ) => {
     entity.metadata.name = `${entity.metadata.name}_${realm}`;
     return entity;
   };
   
   export default async function createPlugin(
     env: PluginEnvironment,
   ): Promise<Router> {
     const builder = await CatalogBuilder.create(env);
   
     /* ... other processors and/or providers ... */
     builder.addEntityProvider(
       KeycloakOrgEntityProvider.fromConfig(env.config, {
         id: 'development',
         logger: env.logger,
         userTransformer,
       }),
     );
   
     const { processingEngine, router } = await builder.build();
     await processingEngine.start();
     return router;
   }
   

   userTransformer is an async function that is expected to resolve to UserEntity object or undefined (if you want to reject the entity) and accepts following parameters:

   • entity: The output of the default parser
   • user: Keycloak user representation
   • realm: Realm name
   • groups: Data about available groups

   groupTransformer is an async function that is expected to resolve to GroupEntity object or undefined (if you want to reject the entity) and accepts following parameters:

   • entity: The output of the default parser
   • group: Keycloak group representation
   • realm: Realm name

Communication between Backstage and Keycloak is enabled by using the Keycloak API. Username/password or client credentials are supported authentication methods.

The following table describes the parameters that you can configure to enable the plugin under catalog.providers.keycloakOrg.<ENVIRONMENT_NAME> object in the app-config.yaml file:

When using client credentials, the access type must be set to confidential and service accounts must be enabled. You must also add the following roles from the realm-management client role:

• query-groups
• query-users
• view-users

Limitations​

If you have self-signed or corporate certificate issues, you can set the following environment variable before starting Backstage:

NODE_TLS_REJECT_UNAUTHORIZED=0

NOTE The solution of setting the environment variable is not recommended.

For users​

Imported users and groups in Backstage using Keycloak plugin​

After configuring the plugin successfully, the plugin imports the users and groups each time when started.

After the first import is complete, you can select User to list the users from the catalog page:

You can see the list of users on the page:

When you select a user, you can see the information imported from Keycloak:

You can also select a group, view the list, and select or view the information imported from Keycloak for a group: