Kubernetes Commands

Automates

• Deployment of containers
• Scaling of containers
• Maintenance of containers

what-is-k8s-kubernetes

Minikube

Minikube Basic controls

brew install minikube

Start/shutdown the cluster

minikube start
minikube stop # Saves the state
minikube delete # Deletes everything

Dashboard

minikube dashboard

Create a namespace

kubectl create ns non-prod

Shell redirection to connect to a Pod

kubectl exec -it new-nginx -- /bin/bash

Access from Another Pod

use a temporary pod to check if the application is reachable from within the cluster

• -i -t flag Allows us to provide input to the container

  kubectl run -it --rm --restart=Never busybox --image=busybox -- sh
  

Then, inside the busybox shell, try to curl your application:

wget -qO- http://<your-pod-ip>:<port-number>/actuator/health

wget -qO- http://10.109.198.72:5000/actuator/health

Debugs & Checks

use autocomplete (for GCP Cloud shell)

source <(kubectl completion bash)

Pod related commands

# Get podname, status
kubectl get pods # podname from minikube dashboard can also be used
export my_pod=[your_pod_name]

#Get details like IP addres, status
kubectl describe pod $my_pod

# Services - #IpAddress, port, clusterId etc
kubectl get service nginx

Deployment related

# Deployment related
kubectl get deployments

# the rollout history of the deployment:
kubectl rollout history deployment nginx-deployment

Check Resource Usage

# to view the resource usage across the nodes of the cluster
kubectl top node

# view the resources being used by the Pod:
kubectl top pods

# Check particular pod
kubectl top pod <pod-name>
kubectl top pod todo-service-app-todo-app-7b45c8749b-ltmfw

Check Application logs

kubectl logs <pod-name>
kubectl logs todo-service-app-todo-app-7b45c8749b-ltmfw

# Running log
kubectl logs -f todo-service-app-todo-app-7b45c8749b-ltmfw

Cluster config

kubectl config view
kubectl cluster-info
kubectl config current-context
kubectl config get-contexts

#  command to change the active context:
kubectl config use-context gke_${DEVSHELL_PROJECT_ID}_Region_autopilot-cluster-1
source <(kubectl completion bash)