Catalog Discovery

Once we have integrated GitLab with Red Hat Developer Hub, we need to enable the autodiscovery capabilities of this provider. Very useful to load our catalog with repositories already created in our GitLab server. That requires to enable the backstage-plugin-catalog-backend-module-gitlab-dynamic dynamic plugin provided by Red Hat Developer Hub.

We will use a new ConfigMap to enable the dynamic plugins:

kind: ConfigMap
apiVersion: v1
metadata:
  name: dynamic-plugins-rhdh
data:
  dynamic-plugins.yaml: |
    includes:
      - dynamic-plugins.default.yaml
    plugins:
      - package: './dynamic-plugins/dist/backstage-plugin-catalog-backend-module-gitlab-dynamic'
        disabled: false
      # GitLab Plugins
      - package: 'oci://ghcr.io/redhat-developer/rhdh-plugin-export-overlays/immobiliarelabs-backstage-plugin-gitlab:bs_1.49.4__7.0.1!immobiliarelabs-backstage-plugin-gitlab'
        integrity: 'sha256:9f758d985ae10c0c9a65931c0dd29c15886315305f3a0fb839517d91761a133f'
        disabled: false
      - package: 'oci://ghcr.io/redhat-developer/rhdh-plugin-export-overlays/immobiliarelabs-backstage-plugin-gitlab-backend:bs_1.49.4__7.0.1!immobiliarelabs-backstage-plugin-gitlab-backend'
        integrity: 'sha256:3d31c16b31c491c42620e9e2172ef26d7f9bfcc4056152f82a5658907bc8ce6a'
        disabled: false

We can create the ConfigMap running:

oc apply -f ./content/modules/ROOT/examples/exercises/dynamic-plugins-3.yaml -n rhdh-gitlab

Add this to the app-config-rhdh ConfigMap:

catalog:
  providers:
    gitlab:
      myGitLab:
        host: gitlab.${BASEDOMAIN} # Identifies one of the hosts set up in the integrations
        apiBaseUrl: https://gitlab.${BASEDOMAIN}/api/v4
        branch: main # Optional. Used to discover on a specific branch
        fallbackBranch: master # Optional. Fallback to be used if there is no default branch configured at the Gitlab repository. It is only used, if `branch` is undefined. Uses `master` as default
        skipForkedRepos: false # Optional. If the project is a fork, skip repository
        entityFilename: catalog-info.yaml # Optional. Defaults to `catalog-info.yaml`
        projectPattern: '[\s\S]*' # Optional. Filters found projects based on provided patter. Defaults to `[\s\S]*`, which means to not filter anything
        schedule: # optional; same options as in TaskScheduleDefinition
          # supports cron, ISO duration, "human duration" as used in code
          frequency: { minutes: 5 }
          # supports ISO duration, "human duration" as used in code
          timeout: { minutes: 15 }

Update the Red Hat Developer Hub manifest to use the new ConfigMap for plugins:

spec:
  application:
  ...
    dynamicPluginsConfigMapName: dynamic-plugins-rhdh

Or run:

oc apply -f ./content/modules/ROOT/examples/exercises/rhdh-app-configmap-3.yaml -n rhdh-gitlab
oc apply -f ./content/modules/ROOT/examples/exercises/rhdh-instance-3.yaml -n rhdh-gitlab

Verify that the sample-app component is located on the Catalog page.

A similar message is registered in the Red Hat Developer Hub pod to confirm the number of projects scanned: 
{"class":"GitlabDiscoveryEntityProvider","level":"\u001b[32minfo\u001b[39m","message":"Processed 1 from scanned 1 projects.","plugin":"catalog","service":"backstage","span_id":"f957c3084bb63955","target":"GitlabDiscoveryEntityProvider:myGitLab","taskId":"GitlabDiscoveryEntityProvider:myGitLab:refresh","taskInstanceId":"06e6c7f9-1f7f-4f2e-a61b-52bc2614b279","timestamp":"2025-03-05 09:27:24","trace_flags":"01","trace_id":"cb4b00f3c9465893e015c5c4b2233d36"}
Enabling the following plugins shows some tabs in each component published in a GitLab server. Those tabs shows the issues, merge requests and other useful information from the repository hosted in the GitLab server. 
      # GitLab Integration Plugins
      - package: 'oci://ghcr.io/redhat-developer/rhdh-plugin-export-overlays/immobiliarelabs-backstage-plugin-gitlab:bs_1.45.3__6.13.0'
        integrity: 'sha256:36b15f74c207839bd59de964030867b5ef7cfadb80fadf38b87d401c7aac5cf1'
        disabled: false
      - package: 'oci://ghcr.io/redhat-developer/rhdh-plugin-export-overlays/immobiliarelabs-backstage-plugin-gitlab-backend:bs_1.45.3__6.13.0'
        integrity: 'sha256:0c5b9ade408c824e957a683e808195177936c58928cd0ee25724079abff53cda'
        disabled: false

Open Catalog in Red Hat Developer Hub and confirm the sample-app component from team-a is listed. Check pod logs for GitlabDiscoveryEntityProvider processed project count.

Learning outcomes

By completing this module, you should understand:

  • How to enable backstage-plugin-catalog-backend-module-gitlab-dynamic

  • How to configure catalog.providers.gitlab in app-config

  • How to verify sample-app appears in the Software Catalog