Host State Machine

During its lifetime, a BareMetalHost resource goes through a series of various states. Some of them are stable (the host stays in them indefinitely without user input), some are transient (the state will change once a certain operation completes). These fields in the status resource define the current state of the host:

status.provisioning.state – the current phase of the provisioning process.
status.operationHistory – the history of the main provisioning phases: registration, inspection, provisioning and deprovisioning.
status.operationalStatus – the overall status of the host.
status.errorType – the type of the current error (if any).
status.poweredOn – the current power state of the host.

This is how the status of a healthy provisioned host may look like:

status:
 # ...
 operationHistory:
    deprovision:
      end: null
      start: null
    inspect:
      end: "2024-06-17T13:09:07Z"
      start: "2024-06-17T13:03:54Z"
    provision:
      end: "2024-06-17T13:11:18Z"
      start: "2024-06-17T13:09:26Z"
    register:
      end: "2024-06-17T13:03:54Z"
      start: "2024-06-17T12:54:18Z"
  operationalStatus: OK
  poweredOn: true
  provisioning:
    ID: e09032ea-1b7d-4c50-bfcd-b94ff7e8d431
    bootMode: UEFI
    image:
      checksumType: sha256
      checksum: http://192.168.0.150/SHA256SUMS
      format: qcow2
      url: http://192.168.0.150/jammy-server-cloudimg-amd64.img
    rootDeviceHints:
      deviceName: /dev/sda
    state: provisioned
 # ...

OperationalStatus

OK – the host is healthy and operational.
discovered – the host is known to Metal3 but lacks the required information for the normal operation (usually, the BMC credentials).
error – error has occured, see the status.errorType and status.errorMessage fields for details.
delayed – cannot proceed with the provisioning because the maximum number of the hosts in the given state has been reached.
detached – the host is detached, no provisioning actions are possible (see detached annotation for details).

Provisioning state machine

BaremetalHost provisioning state transitions

Provisioning states

Creating

Newly created hosts get an empty provisioning state briefly before moving either to unmanaged or registering.

Unmanaged

An unmanaged host is missing both the BMC address and credentials secret name, and does not have any information to access the BMC for registration.

The corresponding operational status is discovered.

Externally Provisioned

An externally provisioned host has been deployed using another tool. Hosts reach this state when they are created with the externallyProvisioned field set to true. Hosts in this state are monitored, and only their power status is managed.

Registering

The host will stay in the registering state while the BMC access details are being validated.

Inspecting

After the host is registered, an IPA ramdisk will be booted on it. The agent collects information about the available hardware components and sends it back to Metal3. The host will stay in the inspecting state until this process is completed.

Preparing

When setting up RAID or changing firmware settings, the host will be in preparing state.

Available

A host in the available state is ready to be provisioned. It will move to the provisioning state once the image field is populated.

Provisioning

While an image is being copied to the host, and the host is configured to run the image, the host will be in the provisioning state.

Provisioned

After an image is copied to the host and the host is running the image, it will be in the provisioned state.

Deprovisioning

When the previously provisioned image is being removed from the host, it will be in the deprovisioning state.

Powering off before delete

When the host that is not currently unmanaged is marked to be deleted, it will be powered off first and will stay in the powering off before delete until it’s done or until the retry limit is reached.

Deleting

When the host is marked to be deleted and has been successfully powered off, it will move from its current state to deleting, at which point the resource record is deleted.

Metal³ user-guide