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

Legacy Backend Configuration

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

app-config.yaml
catalog:
  providers:
    keycloakOrg:
      default:
        # Remove the `/auth` if using keycloak 17+
        baseUrl: https://<keycloak_host>/auth
        loginRealm: ${KEYCLOAK_REALM}
        realm: ${KEYCLOAK_REALM}
        clientId: ${KEYCLOAK_CLIENTID}
        clientSecret: ${KEYCLOAK_CLIENTSECRET}

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:

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: 30 }
          # supports ISO duration, "human duration" as used in code
          timeout: { minutes: 3 }
          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.

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: 30 },
        timeout: { minutes: 3 },
        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.

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

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

New Backend Configuration

Add the following configuration to the app-config.yaml file, and customize the schedule to fit your needs:

app-config.yaml
catalog:
  providers:
    keycloakOrg:
      default:
        # Remove the `/auth` if using keycloak 17+
        baseUrl: https://<keycloak_host>/auth
        loginRealm: ${KEYCLOAK_REALM}
        realm: ${KEYCLOAK_REALM}
        clientId: ${KEYCLOAK_CLIENTID}
        clientSecret: ${KEYCLOAK_CLIENTSECRET}
        schedule: # Mandatory; same options as in TaskScheduleDefinition
          # supports cron, ISO duration, "human duration" as used in code
          frequency: { minutes: 30 } # Customize this to fit your needs
          # supports ISO duration, "human duration" as used in code
          timeout: { minutes: 3 } # Customize this to fit your needs
          initialDelay: { seconds: 15 } # Customize this to fit your needs

packages/backend/src/index.ts
const backend = createBackend();

backend.add(import('@janus-idp/backstage-plugin-keycloak-backend/alpha'));

backend.start();

Optional: To configure custom transformer function for user/group to mutate the entity generated by the keycloak-backend. Create a new backend module with the yarn new command and add your custom user and group transformers to the keycloakTransformerExtensionPoint. Then install this new backend module into your backstage backend. Below is an example of how the backend module can be defined:

plugins/<module-name>/src/module.ts
import {
  GroupTransformer,
  keycloakTransformerExtensionPoint,
  UserTransformer,
} from '@janus-idp/backstage-plugin-keycloak-backend';

const customGroupTransformer: GroupTransformer = async (
  entity,
  realm,
  groups,
) => {
  /* apply transformations */
  return entity;
};
const customUserTransformer: UserTransformer = async (
  entity,
  user,
  realm,
  groups,
) => {
  /* apply transformations */
  return entity;
};

export const keycloakBackendModuleTransformer = createBackendModule({
  pluginId: 'catalog',
  moduleId: 'keycloak-transformer',
  register(reg) {
    reg.registerInit({
      deps: {
        keycloak: keycloakTransformerExtensionPoint,
      },
      async init({ keycloak }) {
        keycloak.setUserTransformer(customUserTransformer);
        keycloak.setGroupTransformer(customGroupTransformer);
      },
    });
  },
});

IMPORTANT

The pluginId for the module MUST be set to catalog to match the pluginId of the keycloak-backend or else the module will fail to initialize.

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:

Name	Description	Default Value	Required
`baseUrl`	Location of the Keycloak server, such as `https://localhost:8443/auth`. Note that Keycloak 17+ omits the `/auth` context path.	""	Yes
`realm`	Realm to synchronize	`master`	No
`loginRealm`	Realm used to authenticate	`master`	No
`username`	Username to authenticate	""	Yes if using password based authentication
`password`	Password to authenticate	""	Yes if using password based authentication
`clientId`	Client ID to authenticate	""	Yes if using client credentials based authentication
`clientSecret`	Client Secret to authenticate	""	Yes if using client credentials based authentication
`userQuerySize`	Number of users to query at a time	`100`	No
`groupQuerySize`	Number of groups to query at a time	`100`	No

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 NODE_TLS_REJECT_UNAUTHORIZED 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:

catalog-list

You can see the list of users on the page:

user-list

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

user-profile

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

group-profile

Authentication and Authorization with Keycloak

Keycloak backend plugin for Backstage

Capabilities​

For administrators​

Installation​

Configuration​

Legacy Backend Configuration​

New Backend Configuration​

Limitations​

For users​

Imported users and groups in Backstage using Keycloak plugin​