Adding external Client Masters

Occasionally administrators will need to connect existing masters to a CloudBees CI cluster, such as in the case of a team requiring a master on Windows.

Existing masters that are connected to Operations Center lack key benefits of Managed Masters like high availability and automatic agent management. Whenever possible, administrators should use a Managed Master with CloudBees CI rather than connecting an existing master.

  • Client Masters are monitored by Operations Center just as Managed Masters are monitored.

  • Administrators can see the status of all their Managed Masters, Team Masters, and Client Masters from the Operations Center masters page.

  • Client Masters can receive configuration updates from Operations Center with configuration snippets.

  • Client Masters can share agents hosted in the cluster, offloading the burden of agent management from teams.

To add an external Client Master:

  1. Sign in.

  2. Navigate to the Operations Center dashboard.

  3. In the left menu, select New Item.

  4. Complete the following information

    • In Item name, type the name of the existing Client Master to connect to the cluster.

    • Select Client Master. Just as with Managed Masters, Client Masters offer some customization and configuration options on creation:

    • On-master executors: Number of builds to execute concurrently on the Client Master itself. The default setting is 2.

    • Email addresses: Contact information for the administrator who is responsible for maintaining the Client Master.

    • Use WebSocket: Select this option to use a WebSocket for the connection. For details about WebSockets, see Using WebSockets to connect masters to Operations Center.

Once these settings are saved, Operations Center will attempt to connect the Client Master to the CloudBees CI cluster.

Verify that Operations Center and the existing Client Master can communicate with each other over both HTTP and JNLP ports. The host and port to use for JNLP is advertised through HTTP headers by each Jenkins master.

You can connect an existing Client Master to Operations Center by giving that Client Master the TLS certificate for Operations Center, typically through the Configure Global Security page in Operations Center. For more information, see How to programmatically connect a Client Master to Operations Center.

If you are connecting multiple Client Masters to your cluster, it is a good idea to automate that task using shared configurations.

Once the Client Master is connected, administrators should configure security and access controls for the master.