How to fix The kubelet is not running in Kubernetes

KubernetesINTERMEDIATECRITICAL

The kubelet service on a node is not running, preventing the node from being part of the cluster.

What this error means

Kubelet is the node agent that registers the node with the cluster and manages Pod lifecycle. If kubelet stops, the node becomes NotReady and cannot run workloads. This is often discovered during kubeadm join or when a node loses connectivity.

Typical symptoms

Node shows NotReady status in kubectl get nodes
Cannot join node to cluster (kubeadm join fails)
Pods on the node cannot start
Node appears disconnected from cluster
kubelet service is stopped or crashed
Journal shows kubelet process exit

Common causes

kubelet service was not started or enabled
kubelet crashed due to out-of-memory or other errors
Container runtime (Docker, containerd) is not running
Network connectivity issue preventing node registration
Insufficient disk space preventing kubelet startup
Configuration or certificate issues

How to fix "The kubelet is not running"

1Check kubelet service status

On the affected node:

bash

sudo systemctl status kubelet
sudo journalctl -u kubelet -n 50 --no-pager

Look for error messages explaining why it stopped.

2Verify container runtime is running

Check if Docker or containerd is running:

bash

sudo systemctl status docker  # or containerd

# Restart if needed
sudo systemctl restart docker

3Start kubelet service

Enable and start kubelet:

bash

sudo systemctl start kubelet
sudo systemctl enable kubelet

# Verify it started
sudo systemctl status kubelet

4Check kubelet logs for errors

Review detailed logs:

bash

sudo journalctl -u kubelet -f  # Follow logs

Common errors:
- "connect: no such file or directory" - container runtime socket issue
- "operation not permitted" - capability/permission issue
- "disk pressure" - not enough space

Advanced notes

Always enable kubelet for auto-start on reboot: sudo systemctl enable kubelet. For kubeadm clusters, kubelet reads config from /etc/kubernetes/kubelet.conf. Monitor disk space as kubelet needs space for image cache and logs. Use kubelet --help to see all configuration options. Check container runtime socket path in kubelet config matches your runtime.

Related errors

Official resources & further reading

📚Kubernetes Official Documentation
📖
Kubernetes: Kubelet Reference(Official Docs)
📖
Kubernetes: Kubeadm Kubelet Troubleshooting(Official Docs)
🐙
GitHub: Kubelet startup issues(GitHub)