[CoreOS] Starting kubelet service in FCOS fails with error: open /var/lib/kubelet/config.yaml: no such file or directory

[Thomas Schneider]

Update:
I have identified additional information relevant for this error:
[core@vm191-fcos ~]$ sudo systemctl status kubelet
* kubelet.service - kubelet: The Kubernetes Node Agent
   Loaded: loaded (/usr/lib/systemd/system/kubelet.service; enabled;
vendor preset: disabled)
  Drop-In: /usr/lib/systemd/system/kubelet.service.d
           `-10-kubeadm.conf
   Active: activating (auto-restart) (Result: exit-code) since Tue
2020-01-28 08:17:31 UTC; 9s ago
     Docs: https://kubernetes.io/docs/
  Process: 284824 ExecStart=/usr/bin/kubelet $KUBELET_KUBECONFIG_ARGS
$KUBELET_CONFIG_ARGS $KUBELET_KUBEADM_ARGS $KUBELET_EXTRA_ARGS
(code=exited, status=255/EXCEPTION)
 Main PID: 284824 (code=exited, status=255/EXCEPTION)

Jan 28 08:17:41 vm191-fcos systemd[1]: kubelet.service: Scheduled
restart job, restart counter is at 7470.
Jan 28 08:17:41 vm191-fcos systemd[1]: Stopped kubelet: The Kubernetes
Node Agent.
Jan 28 08:17:41 vm191-fcos systemd[1]: Started kubelet: The Kubernetes
Node Agent.
Jan 28 08:17:41 vm191-fcos kubelet[284841]: Flag --cgroup-driver has
been deprecated, This parameter should be set via the config file
specified by the Kubelet's --config flag. See
https://kubernetes.io/docs/tasks/administer-cluster/kubelet-config-file/
for more information.
Jan 28 08:17:42 vm191-fcos kubelet[284841]: F0128 08:17:41.999896 
284841 server.go:198] failed to load Kubelet config file
/var/lib/kubelet/config.yaml, error failed to read kubelet config file
"/var/lib/kubelet/config.yaml", error: open
/var/lib/kubelet/config.yaml: no such file or directory
Jan 28 08:17:42 vm191-fcos systemd[1]: kubelet.service: Main process
exited, code=exited, status=255/EXCEPTION
Jan 28 08:17:42 vm191-fcos systemd[1]: kubelet.service: Failed with
result 'exit-code'.

The root cause is clear: /var/lib/kubelet/config.yaml is missing.

This raises the question how K8S should be installed on Fedora CoreOS?
Should I install the packages in "toolbox" using command
sudo dnf install -y kubelet kubeadm kubectl --disableexcludes=kubernetes
or should I install a layered package using command
sudo rpm-ostree install kubelet kubeadm kubectl

Please advise.

THX
Thomas

 

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



Hi,
I have successfully installed FCOS in KVM from ISO.

For installation of K8S I run this command
sudo rpm-ostree install kubelet kubeadm kubectl

There were no issues during installation.
[core@vm192-fcos ~]$ sudo rpm-ostree install kubelet kubeadm kubectl
Checking out tree f480038... done
Enabled rpm-md repositories: updates fedora kubernetes
rpm-md repo 'updates' (cached); generated: 2020-01-21T01:02:46Z
rpm-md repo 'fedora' (cached); generated: 2019-10-23T22:52:47Z
Updating metadata for 'kubernetes'... done
rpm-md repo 'kubernetes'; generated: (invalid timestamp)
Importing rpm-md... done
Resolving dependencies... done
Will download: 10 packages (46.3MB)
Downloading from 'fedora'... done
Downloading from 'kubernetes'... done
Downloading from 'updates'... done
Importing packages... done
Checking out packages... done
Running pre scripts... done
Running post scripts... done
Running posttrans scripts... done
Writing rpmdb... done
Writing OSTree commit... done
Staging deployment... done
Added:
  conntrack-tools-1.4.5-4.fc31.x86_64
  cri-tools-1.13.0-0.x86_64
  ebtables-legacy-2.0.10-37.fc31.x86_64
  ethtool-2:5.4-1.fc31.x86_64
  kubeadm-1.17.2-0.x86_64
  kubectl-1.17.2-0.x86_64
  kubelet-1.17.2-0.x86_64
  libnetfilter_cthelper-1.0.0-16.fc31.x86_64
  libnetfilter_cttimeout-1.0.0-14.fc31.x86_64
  libnetfilter_queue-1.0.2-14.fc31.x86_64
Run "systemctl reboot" to start a reboot

After reboot I tried to start service /kubelet/, but the status shows
that the service fails to run:
[core@vm192-fcos ~]$ sudo systemctl status kubelet
* kubelet.service - kubelet: The Kubernetes Node Agent
   Loaded: loaded (/usr/lib/systemd/system/kubelet.service; enabled;
vendor preset: disabled)
  Drop-In: /usr/lib/systemd/system/kubelet.service.d
           `-10-kubeadm.conf
   Active: activating (auto-restart) (Result: exit-code) since Wed
2020-01-22 08:03:05 UTC; 1s ago
     Docs: https://kubernetes.io/docs/
  Process: 2592 ExecStart=/usr/bin/kubelet $KUBELET_KUBECONFIG_ARGS
$KUBELET_CONFIG_ARGS $KUBELET_KUBEADM_ARGS $KUBELET_EXTRA_ARGS
(code=exited, status=255/EXCEPTION)
 Main PID: 2592 (code=exited, status=255/EXCEPTION)

Can you please advise why the service is not starting?
Is the procedure for installation of K8S incorrect?

THX