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/v0.10.3/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.config=http://$PUBLIC_IP:8081/configdata?uuid=
      - talos.platform=metal
  initrd:
    url: "https://github.com/talos-systems/talos/releases/download/v0.10.3/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
  ...