Chapter 11. Managing bare-metal hosts

Procedure

1. In the web console, navigate to Compute Bare Metal Hosts.
2. Select Add Host New with Dialog.
3. Specify a unique name for the new bare metal host.
4. Set the Boot MAC address.
5. Set the Baseboard Management Console (BMC) Address.
6. Enter the user credentials for the host’s baseboard management controller (BMC).
7. Select to power on the host after creation, and select Create.
8. Scale up the number of replicas to match the number of available bare metal hosts. Navigate to Compute MachineSets, and increase the number of machine replicas in the cluster by selecting Edit Machine count from the Actions drop-down menu.

Procedure

1. In the web console, navigate to Compute Bare Metal Hosts.
2. Select Add Host New from YAML.

3. Copy and paste the below YAML, modifying the relevant fields with the details of your host:

   apiVersion: metal3.io/v1alpha1
   kind: BareMetalHost
   metadata:
     name: <bare_metal_host_name>
   spec:
     online: true
     bmc:
       address: <bmc_address>
       credentialsName: <secret_credentials_name>  

   1

   
       disableCertificateVerification: True 

   2

   
     bootMACAddress: <host_boot_mac_address>

   1

   credentialsName must reference a valid Secret CR. The baremetal-operator cannot manage the bare metal host without a valid Secret referenced in the credentialsName. For more information about secrets and how to create them, see Understanding secrets.

   2

   Setting disableCertificateVerification to true disables TLS host validation between the cluster and the baseboard management controller (BMC).

4. Select Create to save the YAML and create the new bare metal host.

5. Scale up the number of replicas to match the number of available bare metal hosts. Navigate to Compute MachineSets, and increase the number of machines in the cluster by selecting Edit Machine count from the Actions drop-down menu.

   Note

   You can also manage the number of bare metal nodes using the

   oc scale

   command and the appropriate bare metal compute machine set.

Procedure

1. Annotate the compute machine set that you want to configure for automatic scaling by adding the

   metal3.io/autoscale-to-hosts

   annotation. Replace

   <machineset>

   with the name of the compute machine set.

   $ oc annotate machineset <machineset> -n openshift-machine-api 'metal3.io/autoscale-to-hosts=<any_value>'

   Wait for the new scaled machines to start.

Procedure

1. Annotate the compute machine set that you want to remove from the provisioner node by adding the

   baremetalhost.metal3.io/detached

   annotation.

   $ oc annotate machineset <machineset> -n openshift-machine-api 'baremetalhost.metal3.io/detached'

   Wait for the new machines to start.

   Note

   When you use a

   BareMetalHost

   object to create a machine in the cluster and labels or selectors are subsequently changed on the

   BareMetalHost

   , the

   BareMetalHost

   object continues be counted against the

   MachineSet

   that the

   Machine

   object was created from.

2. In the provisioning use case, remove the annotation after the reboot is complete by using the following command:

   $ oc annotate machineset <machineset> -n openshift-machine-api 'baremetalhost.metal3.io/detached-'

Procedure

1. In the web console, mark the node that you want to power off as unschedulable. Perform the following steps:

   1. Navigate to Nodes and select the node that you want to power off. Expand the Actions menu and select Mark as unschedulable.
   2. Manually delete or relocate running pods on the node by adjusting the pod deployments or scaling down workloads on the node to zero. Wait for the drain process to complete.
   3. Navigate to Compute Bare Metal Hosts.
   4. Expand the Options menu for the bare-metal host that you want to power off, and select Power Off. Select Immediate power off.

2. Alternatively, you can patch the

   BareMetalHost

   resource for the host that you want to power off by using

   oc

   .

   1. Get the name of the managed bare-metal host. Run the following command:

      $ oc get baremetalhosts -n openshift-machine-api -o jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.status.provisioning.state}{"\n"}{end}'

      Example output

      master-0.example.com  managed
      master-1.example.com  managed
      master-2.example.com  managed
      worker-0.example.com  managed
      worker-1.example.com  managed
      worker-2.example.com  managed

   2. Mark the node as unschedulable:

      $ oc adm cordon <bare_metal_host> 

      1

      1

      <bare_metal_host> is the host that you want to shut down, for example, worker-2.example.com.

   3. Drain all pods on the node:

      $ oc adm drain <bare_metal_host> --force=true

      Pods that are backed by replication controllers are rescheduled to other available nodes in the cluster.

   4. Safely power off the bare-metal host. Run the following command:

      $ oc patch <bare_metal_host> --type json -p '[{"op": "replace", "path": "/spec/online", "value": false}]'

   5. After you power on the host, make the node schedulable for workloads. Run the following command:

      $ oc adm uncordon <bare_metal_host>