Restart a bare metal host¶

You can use the Container Cloud API to restart a bare metal host in Mirantis OpenStack for Kubernetes clusters. The workflow of the host restart is as follows:

Set the maintenance mode on the cluster that contains the target node.
Set the maintenance mode on the target node for OpenStack and Container Cloud to drain it from workloads. No new workloads will be provisioned to a host in the maintenance mode.
Use the bare metal host object to initiate a hard reboot of the bare metal server that hosts the node.

To restart a bare metal host:

Using kubeconfig of the Container Cloud management cluster, access the Container Cloud API and open the Cluster object for editing:
```
kubectl -n <project-name> edit cluster <cluster-name>
```
Add the following field to the spec section to set the maintenance mode on the cluster:
```
spec:
  providerSpec:
    value:
      maintenance: true
```

Verify that the Cluster object status for Maintenance is ready: true:

kubectl -n <project-name> get cluster <cluster-name>

Example of a negative system response:

...
status:
  providerStatus:
    conditions:
    ...
    - message: 'Maintenance state of the cluster is false, expected:
      # true. Waiting for the cluster to enter the maintenance state'
      ready: false
      type: Maintenance
    ...
    maintenance: true

Open the required Machine object for editing:

kubectl -n <project-name> edit machine <machine-name>

In the spec:providerSpec section, set the maintenance mode on the node:

spec:
  providerSpec:
    value:
      maintenance: true

In the annotations section of the Machine definition, capture the bare metal host name connected to the machine:
```
metadata:
  annotations:
    metal3.io/BareMetalHost: <project-name>/<host-name>
```
Verify that the Machine maintenance status is true:
```
status:
  maintenance: true
```
Important

Proceed with the node maintenance only after the machine switches to the maintenance mode.
Open the required bare metal host object for editing using the previously captured <host-name>:
Since the management cluster update to 16.4.0 (MCC 2.29.0)
kubectl -n <project-name> edit baremetalhostinventory <host-name>
Caution

While the Cluster release of the management cluster is 16.4.0, BareMetalHostInventory operations are allowed to m:kaas@management-admin only. This limitation is lifted once the management cluster is updated to the Cluster release 16.4.1 or later.
Before the management cluster update to 16.4.0 (MCC 2.29.0)
kubectl -n <project-name> edit baremetalhost <host-name>
In the spec section, set the online field to false:
```
spec:
  online: false
```
Wait for the host to shut down.
In the spec section, set the online field to true:
```
spec:
  online: true
```
Restore the machine from the maintenance mode by deleting the previously set maintenance: true line from the Machine object:
```
kubectl -n <project-name> edit machine <machine-name>
```
Restore the cluster from the maintenance mode by deleting the previously set maintenance: true line from the Cluster object.
```
kubectl -n <project-name> edit cluster <cluster-name>
```