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Resource Configuration

1 - Environments

Environments are a custom resource provided by the Metal Controller Manager. An environment is a codified description of what should be returned by the PXE server when a physical server attempts to PXE boot.

Especially important in the environment types are the kernel args. From here, one can tweak the IP to the metadata server as well as various other kernel options that Talos and/or the Linux kernel supports.

Environments can be supplied to a given server either at the Server or the ServerClass level. The hierarchy from most to least respected is:

  • .spec.environmentRef provided at Server level
  • .spec.environmentRef provided at ServerClass level
  • "default" Environment created automatically and modified by an administrator

A sample environment definition looks like this:

apiVersion: metal.sidero.dev/v1alpha1
kind: Environment
metadata:
  name: default
spec:
  kernel:
    url: "https://github.com/talos-systems/talos/releases/download/v0.14.0/vmlinuz-amd64"
    sha512: ""
    args:
      - console=tty0
      - console=ttyS1,115200n8
      - consoleblank=0
      - earlyprintk=ttyS1,115200n8
      - ima_appraise=fix
      - ima_hash=sha512
      - ima_template=ima-ng
      - init_on_alloc=1
      - initrd=initramfs.xz
      - nvme_core.io_timeout=4294967295
      - printk.devkmsg=on
      - pti=on
      - random.trust_cpu=on
      - slab_nomerge=
      - talos.platform=metal
  initrd:
    url: "https://github.com/talos-systems/talos/releases/download/v0.14.0/initramfs-amd64.xz"
    sha512: ""

Example of overriding "default" Environment at the Server level:

apiVersion: metal.sidero.dev/v1alpha1
kind: Server
...
spec:
  environmentRef:
    namespace: default
    name: boot
  ...

Example of overriding "default" Environment at the ServerClass level:

apiVersion: metal.sidero.dev/v1alpha1
kind: ServerClass
...
spec:
  environmentRef:
    namespace: default
    name: boot
  ...

2 - 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.

Other Settings

cordoned

If cordoned is set to true, Server gets excluded from any ServerClass it might match based on qualifiers. This means that the Server will not be allocated automatically.

Server might be cordoned to temporarily take it out of the ServerClass to perform for example hardware maintenance.

apiVersion: metal.sidero.dev/v1alpha1
kind: Server
...
spec:
  cordoned: true

pxeBootAlways

Server might be forced to boot from the network even if the OS is already installed with pxeBootAlways: true:

apiVersion: metal.sidero.dev/v1alpha1
kind: Server
...
spec:
  pxeBootAlways: true

bootFromDiskMethod

The method to exit iPXE network boot to force boot from disk can be configured for the Server:

apiVersion: metal.sidero.dev/v1alpha1
kind: Server
...
spec:
  bootFromDiskMethod: ipxe-sanboot

Valid values are:

  • ipxe-exit
  • http-404
  • ipxe-sanboot

If not set, the ServerClass.spec.bootFromDiskMethod value is used with the fallback to the default boot from disk method (SIDERO_CONTROLLER_MANAGER_BOOT_FROM_DISK_METHOD).

3 - Server Classes

Server classes are a way to group distinct server resources. The qualifiers and selector keys allow the administrator to specify criteria upon which to group these servers. If both of these keys are missing, the server class matches all servers that it is watching. If both of these keys define requirements, these requirements are combined (logical AND).

selector

selector groups server resources by their labels. The Kubernetes documentation has more information on how to use this field.

qualifiers

There are currently two keys: cpu, systemInformation. Each of these keys accepts a list of entries. The top level keys are a “logical AND”, while the lists under each key are a “logical OR”. Qualifiers that are not specified are not evaluated.

An example:

apiVersion: metal.sidero.dev/v1alpha1
kind: ServerClass
metadata:
  name: serverclass-sample
spec:
  selector:
    matchLabels:
      common-label: "true"
    matchExpressions:
      - key: zone
        operator: In
        values:
          - central
          - east
      - key: environment
        operator: NotIn
        values:
          - prod
  qualifiers:
    cpu:
      - manufacturer: "Intel(R) Corporation"
        version: "Intel(R) Atom(TM) CPU C3558 @ 2.20GHz"
      - manufacturer: Advanced Micro Devices, Inc.
        version: AMD Ryzen 7 2700X Eight-Core Processor
    systemInformation:
      - manufacturer: Dell Inc.

Servers would only be added to the above class if they:

  • had EITHER CPU info
  • AND the label key/value in matchLabels
  • AND match the matchExpressions

Additionally, Sidero automatically creates and maintains a server class called "any" that includes all (accepted) servers. Attempts to add qualifiers to it will be reverted.

configPatches

Server configs of servers matching a server class can be updated by using the configPatches section of the custom resource. See patching for more information on how this works.

An example of settings the default install disk for all servers matching a server class:

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

Other Settings

environmentRef

Servers from a ServerClass can be set to use the specific Environment by linking the Environment from the ServerClass:

apiVersion: metal.sidero.dev/v1alpha1
kind: ServerClass
...
spec:
  environmentRef:
    name: production-env

bootFromDiskMethod

The method to exit iPXE network boot to force boot from disk can be configured for all Server resources belonging to the ServerClass:

apiVersion: metal.sidero.dev/v1alpha1
kind: ServerClass
...
spec:
  bootFromDiskMethod: ipxe-sanboot

Valid values are:

  • ipxe-exit
  • http-404
  • ipxe-sanboot

If not set, the default boot from disk method is used (SIDERO_CONTROLLER_MANAGER_BOOT_FROM_DISK_METHOD).

4 - Metadata

The Sidero controller manager manages the Machine metadata. In terms of Talos (the OS on which the Kubernetes cluster is formed), this is the “machine config”, which is used during the automated installation.

Talos Machine Configuration

The configuration of each machine is constructed from a number of sources:

  • The TalosControlPlane custom resource for control plane nodes.
  • The TalosConfigTemplate custom resource.
  • The ServerClass which was used to select the Server into the Cluster.
  • Any Server-specific patches.

An example usage of setting a virtual IP for the control plane nodes and adding extra node-labels to nodes is shown below:

Note: because of the way JSON patches work the interface setting also needs to be set in TalosControlPlane when defining a Virtual IP. This experience is not ideal, but will be addressed in a future release.

TalosControlPlane custom resource:

apiVersion: controlplane.cluster.x-k8s.io/v1alpha3
kind: TalosControlPlane
metadata:
  name: workload-cluster
  namespace: default
spec:
  controlPlaneConfig:
    controlplane:
      configPatches:
      - op: add
        path: /machine/network
        value:
          interfaces:
          - interface: eth0
            dhcp: true
            vip:
              ip: 172.16.200.52
      generateType: controlplane
      talosVersion: v0.13
    init:
      configPatches:
      - op: add
        path: /machine/network
        value:
          interfaces:
          - interface: eth0
            dhcp: true
            vip:
              ip: 172.16.200.52
      generateType: init
      talosVersion: v0.13
  infrastructureTemplate:
    apiVersion: infrastructure.cluster.x-k8s.io/v1alpha3
    kind: MetalMachineTemplate
    name: workload-cluster
  replicas: 3
  version: v1.23.0

TalosConfigTemplate custom resource:

---
apiVersion: bootstrap.cluster.x-k8s.io/v1alpha3
kind: TalosConfigTemplate
metadata:
  name: workload-cluster
  namespace: default
spec:
  template:
    spec:
      generateType: join
      talosVersion: v0.13
      configPatches:
      - op: add
        path: /machine/kubelet
        value:
          extraArgs:
            node-labels:
              talos.dev/part-of: cluster/workload-cluster

and finally in the control plane ServerClass custom resource we augment the network information for other interfaces:

---
apiVersion: metal.sidero.dev/v1alpha1
kind: ServerClass
metadata:
  name: cp.small.x86
spec:
  configPatches:
  - op: replace
    path: /machine/install/disk
    value: /dev/nvme0n1
  - op: add
    path: /machine/install/extraKernelArgs
    value:
    - console=tty0
    - console=ttyS1,115200n8
  - op: add
    path: /machine/network/interfaces/-
    value:
      interface: eth1
      dhcp: true
  qualifiers:
    cpu:
    - version: Intel(R) Xeon(R) E-2124G CPU @ 3.40GHz
    systemInformation:
    - manufacturer: Supermicro
  selector:
    matchLabels:
      metal.sidero.dev/serverclass: cp.small.x86

the workload ServerClass defines the complete networking config

---
apiVersion: metal.sidero.dev/v1alpha1
kind: ServerClass
metadata:
  name: general.medium.x86
spec:
  configPatches:
  - op: replace
    path: /machine/install/disk
    value: /dev/nvme1n1
  - op: add
    path: /machine/install/extraKernelArgs
    value:
    - console=tty0
    - console=ttyS1,115200n8
  - op: add
    path: /machine/network
    value:
      interfaces:
      - interface: eth0
        dhcp: true
      - interface: eth1
        dhcp: true
  qualifiers:
    cpu:
    - version: Intel(R) Xeon(R) E-2136 CPU @ 3.30GHz
    systemInformation:
    - manufacturer: Supermicro
  selector:
    matchLabels:
      metal.sidero.dev/serverclass: general.medium.x86

The base template is constructed from the Talos bootstrap provider, using data from the associated TalosControlPlane and TalosConfigTemplate manifest. Then, any configuration patches are applied from the ServerClass and Server.

These patches take the form of an RFC 6902 JSON (or YAML) patch. An example of the use of this patch method can be found in Patching Guide.

Also note that while a Server can be a member of any number of ServerClasses, only the ServerClass which is used to select the Server into the Cluster will be used for the generation of the configuration of the Machine. In this way, Servers may have a number of different configuration patch sets based on which Cluster they are in at any given time.