Chapter 14. 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.

   Note

   You can also manage the number of bare-metal nodes by using the oc scale command and the appropriate bare-metal compute machine set.

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>
       disableCertificateVerification: True
     bootMACAddress: <host_boot_mac_address>
   # ...

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   where:

   spec.bmc.credentialsName

   Specifies a reference to a valid Secret CR. The Bare Metal 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".

   spec.bmc.disableCertificateVerification

   Specifies whether to require TLS host validation between the cluster and the baseboard management controller (BMC). When this field is set to true, TLS host validation is disabled.

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 by using the oc scale command and the appropriate bare-metal compute machine set.

Procedure

1. To configure automatic scaling for a compute machine set, annotate the compute machine set by running the following command:

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

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   • <machineset>: Specifies the name of the compute machine set that you want to configure for automatic scaling.
   • <any_value> Specifies is a value, such as true or "".

2. Wait for the new scaled machines to start.

   Note

   The BareMetalHost object continues to be counted against the MachineSet that the Machine object was created from when the following conditions are met:

   • You use a BareMetalHost object to create a machine in the cluster.
   • You subsequently change labels or selectors on the BareMetalHost.

Procedure

1. To configure automatic scaling for a compute machine set, annotate the compute machine set by running the following command:

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

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   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 to 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-'

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Procedure

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.
5. Select Immediate power off.

Procedure

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

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

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   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

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2. Mark the node as unschedulable by entering the following command:

   $ oc adm cordon <bare_metal_host>

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   • <bare_metal_host>: Specifies the name of the host that you want to shut down. For example, worker-2.example.com.

3. Drain all pods on the node by entering the following command:

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

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

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

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

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

   $ oc adm uncordon <bare_metal_host>

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