How to install a service in Fedora CoreOS

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,
1

I’m running k0s on Fedora CoreOS, and any time I shutdown the server, I have to reinstall the service. It survives a soft reboot fine. There is a service file that gets installed into /etc/systemd/system/ but is wiped at restart. What’s the proper way to handle this? I could write the file there through the ignition file, but would that cause a problem on first boot before I have installed k0s? Thanks for any guidance.

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2

Are you running a “live” system? Live systems run from memory and all changes are lost when the system is powered off.

I guess if you let us know how you are running in (maybe point to a docs page that you are following) that would help.

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Ah, maybe that’s what I’m doing. Still trying to figure out how this works. :smile:

I’m running it on kubevirt, and basing my setup off this doc. Provisioning Fedora CoreOS on KubeVirt :: Fedora Docs

Here is my butane file.

variant: fcos
version: 1.4.0
storage:
  disks:
    - device: /dev/vdb
      wipe_table: false
      partitions:
      - number: 1
        label: var
        size_mib: 0 
  filesystems:
    - path: /var
      device: /dev/disk/by-partlabel/var
      format: xfs
      with_mount_unit: true  
  files:
    - path: /etc/NetworkManager/system-connections/enp1s0.nmconnection
      mode: 0600
      contents:
        inline: |
          [connection]
          id=enp1s0
          type=ethernet
          interface-name=enp1s0
          [ipv4]
          address1=10.3.3.20/24,10.3.3.1
          dns=8.8.8.8;
          dns-search=
          may-fail=false
          method=manual
    - path: /etc/hostname
      mode: 0644
      contents:
        inline: k8s-node1
passwd:
  users:
    - name: core
      groups:
        - sudo
      ssh_authorized_keys:
        - mykey
4

This points to your entire system being reprovisioned from scratch when you shut it down. Are any other changes in /etc preserved? If you want to keep this logic then you need to declare all configuration changes that you want in /etc in you Ignition config.

5

I think that’s what’s happening. Pretty sure nothing is preserved. I guess I thought that was just how this all worked. I’d be happy to have it installed instead, just not sure how to get there from here. I started with ISO installs on Proxmox, but my challenge was getting the Ignition file into it for initial setup. Trying to avoid running a web server to host the config, so I was having to create an ignition ISO to mount on the VM every time I changed a configuration. It was kind of a hassle, so when I discovered I could launch the kubevirt image and have the ignition config stored in a k8s secret, it suddenly made things super easy for me to get going. Turns out not so easy to keep things going. :grin:

6

Ahh. You know we are learning more and more about kubevirt ourselves as we go through this. What I’ve found out over time is that a “containerdisk” in kubevirt land isn’t something that’s persistent. i.e. it’s kind of like containers where when you stop a container and start it again anything that wasn’t in a Volume is gone. That’s what you are hitting here.

You can try to start a virtual machine type and use the data importer stuff to get the container imported into an actual PV (i.e. the OS will be persistent). Try with something like this:

---
apiVersion: kubevirt.io/v1
kind: VirtualMachine
metadata:
  name: fcos
spec:
  runStrategy: Always
  dataVolumeTemplates:
  - metadata:
      name: fcos-os-disk-volume
    spec:
      storage:
        volumeMode: Block
        resources:
          requests:
            storage: 10Gi
        accessModes:
          - ReadWriteOnce
      source:
        registry:
          url: "docker://quay.io/fedora/fedora-coreos-kubevirt:stable"
  template:
    spec:
      domain:
        devices:
          disks:
          - disk:
              bus: virtio
            name: fcos-os-disk
          - disk:
              bus: virtio
            name: cloudinitdisk
          rng: {}
        resources:
          requests:
            memory: 2048M
      volumes:
      - dataVolume:
          name: fcos-os-disk-volume
        name: fcos-os-disk
	  - name: cloudinitdisk
		cloudInitConfigDrive:
		  secretRef:
			name: ignition-payload

Depending on your cluster you may need to set storageClassName: name under dataVolumeTemplates.spec.storage.

7

Look at the .service file and find the missing files and copy and paste into a folder where they belong.

8

I opened a PR to enhance the docs: provisioning/kubevirt: add persistent disk example by dustymabe · Pull Request #580 · coreos/fedora-coreos-docs · GitHub

9

Super. Thanks so much! I’m going to give this a try.