Kubernetes - Static Pod

What is a Static Pod? 🛑
Static Pods are created by Kubelet without the intervention of the kube-apiserver or any other control plane components.

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Where is the Static Pod manifest location in a node? 📂
The manifest files for Static Pods are located in the /etc/kubernetes/manifests folder.

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How will Kubelet create a Pod without kube-apiserver? 🔄
By default, Kubelet periodically checks the pod manifest location (e.g., /etc/kubernetes/manifests). If there are changes in the manifest file or if the Pod crashes, Kubelet will automatically recreate the Pod.

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Will Kubelet serve only Static Pod requests? ❌
No, Kubelet processes both HTTP API requests (from the kube-apiserver) and Static Pods.

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Will kube-apiserver be aware of the Static Pod created by Kubelet? ✅
Yes! When Kubelet creates a Static Pod, it also creates a read-only mirror object in the kube-apiserver. This allows the Static Pod to be visible when running kubectl get pods.

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How to identify a Static Pod using kubectl get command? 🔍
The Pod name of a Static Pod is appended with the node name of the cluster where the Static Pod is running.

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is it possible to create deployment,replicaset etc same like as static pod ? ❌

No, it is not possible to create Deployment or ReplicaSet objects by placing their definition files under the /etc/kubernetes/manifests directory.

For Deployments and ReplicaSets, the control plane (e.g., kube-apiserver and kube-controller-manager) is required.

How to delete a Static Pod? 🗑️
Simply move the Pod definition file out of the Static Pod manifest directory (/etc/kubernetes/manifests).

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What is the primary use case of Static Pods? 🎯
Since Static Pods do not depend on Kubernetes control plane components, they are often used to deploy control plane components themselves. For example:

1. Install Kubelet on all master nodes.

2. Place Pod definition files in the /etc/kubernetes/manifests directory, using Docker images for components like kube-apiserver, etcd, and kube-controller-manager.

This approach eliminates the need to download binaries or worry about service crashes for control plane components.

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🔑 👉 Key Takeaways👇 🔑:

• Static Pods are managed solely by Kubelet.

• They are stored in /etc/kubernetes/manifests.

• Kubelet can manage both Static Pods and API-server-created Pods.

• Static Pods are mirrored in the kube-apiserver for visibility.

• Use Static Pods to bootstrap control plane components in a cluster.

#Kubernetes #StaticPods #Kubelet #ControlPlane #DevOps