CKA — Static Pods

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What Are Static Pods?

Static Pods are managed directly by the kubelet on a specific node, without the API server observing them. The kubelet watches a directory (typically /etc/kubernetes/manifests/) and automatically creates Pods for any manifest files found there.

All control plane components in a kubeadm cluster run as static Pods:

  • kube-apiserver
  • etcd
  • kube-scheduler
  • kube-controller-manager

Static Pod vs Regular Pod

Aspect Static Pod Regular Pod
Created by kubelet (from manifest file) API server (from kubectl, controller)
Manifest location /etc/kubernetes/manifests/ etcd (via API server)
Visible in API Yes (as a mirror Pod, read-only) Yes (fully managed)
Can be deleted via kubectl No (kubelet recreates it) Yes
Scheduling Always on the node where manifest exists Scheduled by kube-scheduler
Naming <name>-<node-name> suffix Name as specified
Use case Control plane components Application workloads

The Manifests Directory

# Default static Pod manifest path
/etc/kubernetes/manifests/

# This path is configured in kubelet config
cat /var/lib/kubelet/config.yaml | grep staticPodPath
# Output: staticPodPath: /etc/kubernetes/manifests

# List control plane static Pods
ls /etc/kubernetes/manifests/
# etcd.yaml
# kube-apiserver.yaml
# kube-controller-manager.yaml
# kube-scheduler.yaml

Creating a Static Pod

To create a static Pod, place a manifest file in the static Pod directory:

# Create a static Pod manifest
sudo cat > /etc/kubernetes/manifests/static-web.yaml << EOF
apiVersion: v1
kind: Pod
metadata:
  name: static-web
  labels:
    role: static
spec:
  containers:
  - name: nginx
    image: nginx:1.27
    ports:
    - containerPort: 80
EOF

# The kubelet automatically detects and creates the Pod
# Check it (name will have the node suffix)
kubectl get pods -A | grep static-web
# static-web-<node-name>   1/1   Running   0   10s

Modifying a Static Pod

To modify a static Pod, edit the manifest file directly. The kubelet detects the change and recreates the Pod:

# Edit the manifest
sudo vim /etc/kubernetes/manifests/kube-apiserver.yaml

# The kubelet will automatically restart the Pod with new config
# Watch for it
kubectl get pods -n kube-system -w

Warning: Be very careful when editing control plane static Pod manifests. A syntax error can take down the API server, making kubectl unusable. Always verify YAML syntax before saving.

Deleting a Static Pod

# You CANNOT delete a static Pod via kubectl — kubelet will recreate it
kubectl delete pod static-web-<node-name>
# Pod gets recreated immediately

# To truly remove a static Pod, remove the manifest file
sudo rm /etc/kubernetes/manifests/static-web.yaml
# Now the Pod is gone permanently

Finding Static Pods

# Static Pods always have the node name as a suffix
kubectl get pods -A -o wide | grep -E "control|master"

# Check which Pods are static by looking for the mirror Pod annotation
kubectl get pod kube-apiserver-master -n kube-system -o yaml | grep -A2 annotations
# kubernetes.io/config.mirror: <hash>

Troubleshooting Static Pods

If a control plane component is not working:

# 1. Check if the manifest file exists and has valid YAML
sudo cat /etc/kubernetes/manifests/kube-apiserver.yaml | head

# 2. Check kubelet logs for errors
journalctl -u kubelet -f | grep -i error

# 3. Check container runtime for the container
crictl ps -a | grep kube-apiserver

# 4. Check container logs directly
crictl logs <container-id>

Exam tip: If the API server is down and kubectl does not work, use crictl and journalctl to troubleshoot. Check the manifest files for syntax errors and the kubelet logs for failure details.

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