Demystifying Kubernetes: A Guide to Node and Pod Management

Node Exploration

View Node Information

To gather information about your Kubernetes nodes, use the following commands:

kubectl get no

For a more detailed view, including internal IP addresses and node conditions, use:

kubectl get no -o wide

To delve even deeper into a specific node, run:

kubectl describe no <node-name>

Pod Insights

List Pods

To list all pods in the default namespace, use:

kubectl get po

For a wider view, including additional information like node placement, execute:

kubectl get po -o wide

Pod Details and Configuration
Retrieve the YAML representation of a pod for detailed information:

kubectl get po <pod name> -o yaml

Alternatively, obtain the JSON representation:

kubectl get po <pod name> -o json

For an insightful narrative about a specific pod, use:

kubectl describe po <pod name>

Pod Operations
Delete a specific pod:

kubectl delete po <pod name>

Or, clear the slate by deleting all pods:

kubectl delete po --all

Apply changes from a pod definition file:

kubectl apply -f <pod.yaml> -n <namespace-name>

Pod Editing
Extract a pod's definition to a file for editing:

kubectl get po <pod-name> -o yaml > pod.yaml
vi pod.yaml
kubectl delete po <pod-name>
kubectl apply -f pod.yaml

Edit pod properties in-place:

kubectl edit po <pod-name>

Pod Creation
Create a simple nginx pod with dry-run:

kubectl run nginx --image=nginx --dry-run=client -o yaml > pod.yaml

Executing Commands Inside Pods
Execute a command inside a running container:

kubectl exec [POD] -- [COMMAND]
kubectl exec nginx -- ls /
kubectl exec -it nginx -- /bin/sh
kubectl exec -it web -c nginx -- /bin/bash

Multicontainer Pods
In multicontainer pods, containers are created and destroyed together. InitContainers, located under spec, have properties like name and image.

Additional Tips
Use kubectl get po -A to list all pods in all namespaces.
Troubleshoot errors across namespaces with kubectl get events -A | grep error.
Pods have a restartPolicy property with values: Always, Never, or OnFailure (default is Always).
Note: kubectl run creates pods, not deployments. There's no imperative command like kubectl create po for pod creation.

Explore the vast world of Kubernetes management with confidence! Happy Kuberneting!