Servers

Servers are the basic resource of bare metal in the Metal Controller Manager. These are created by PXE booting the servers and allowing them to send a registration request to the management plane.

An example server may look like the following:

apiVersion: metal.sidero.dev/v1alpha1
kind: Server
metadata:
  name: 00000000-0000-0000-0000-d05099d333e0
  labels:
    common-label: "true"
    zone: east
    environment: test
spec:
  accepted: false
  configPatches:
    - op: replace
      path: /cluster/network/cni
      value:
        name: custom
        urls:
          - http://192.168.1.199/assets/cilium.yaml
  cpu:
    manufacturer: Intel(R) Corporation
    version: Intel(R) Atom(TM) CPU C3558 @ 2.20GHz
  system:
    manufacturer: Dell Inc.

Installation Disk

An installation disk is required by Talos on bare metal. This can be specified in a configPatch:

apiVersion: metal.sidero.dev/v1alpha1
kind: Server
...
spec:
  accepted: false
  configPatches:
    - op: replace
      path: /machine/install/disk
      value: /dev/sda

The install disk patch can also be set on the ServerClass:

apiVersion: metal.sidero.dev/v1alpha1
kind: ServerClass
...
spec:
  configPatches:
    - op: replace
      path: /machine/install/disk
      value: /dev/sda

Server Acceptance

In order for a server to be eligible for consideration, it must be accepted. This is an important separation point which all Servers must pass. Before a Server is accepted, no write action will be performed against it. Thus, it is safe for a computer to be added to a network on which Sidero is operating. Sidero will never write to or wipe any disk on a computer which is not marked as accepted.

This can be tedious for systems in which all attached computers should be considered to be under the control of Sidero. Thus, you may also choose to automatically accept any machine into Sidero on its discovery. Please keep in mind that this means that any newly-connected computer WILL BE WIPED automatically. You can enable auto-acceptance by passing the --auto-accept-servers=true flag to sidero-controller-manager.

Once accepted, a server will be reset (all disks wiped) and then made available to Sidero.

You should never change an accepted Server to be not accepted while it is in use. Because servers which are not accepted will not be modified, if a server which was accepted is changed to not accepted, the disk will not be wiped upon its exit.

IPMI

Sidero can use IPMI information to control Server power state, reboot servers and set boot order.

IPMI information will be, by default, setup automatically if possible as part of the acceptance process. In this design, a “sidero” user will be added to the IPMI user list and a randomly generated password will be issued. This information is then squirreled away in a Kubernetes secret in the sidero-system namespace, with a name format of <server-uuid>-bmc. Users wishing to turn off this feature can pass the --auto-bmc-setup=false flag to sidero-controller-manager

IPMI connection information can also be set manually in the Server spec after initial registration:

apiVersion: metal.sidero.dev/v1alpha1
kind: Server
...
spec:
  bmc:
    endpoint: 10.0.0.25
    user: admin
    pass: password

If IPMI information is set, server boot order might be set to boot from disk, then network, Sidero will switch servers to PXE boot once that is required.

Without IPMI info, Sidero can still register servers, wipe them and provision clusters, but Sidero won’t be able to reboot servers once they are removed from the cluster. If IPMI info is not set, servers should be configured to boot first from network, then from disk.

Sidero can also fetch IPMI credentials via the Secret reference:

apiVersion: metal.sidero.dev/v1alpha1
kind: Server
...
spec:
  bmc:
    endpoint: 10.0.0.25
    userFrom:
      secretKeyRef:
        name: ipmi-credentials
        key: username
    passFrom:
      secretKeyRef:
        name: ipmi-credentials
        key: password

As the Server resource is not namespaced, Secret should be created in the default namespace.