Minikube_Cheatsheet

Kubernetes vs. Docker

Build an image
docker build -t kub-first-app .
Make sure cluster is running
minikube status
See list of available kubectl commands
kubectl help
Create deployment object
kubectl create deployment first-app --image=kub-first-app
Get list of created deployments and pods
kubectl get deployments
kubectl get pods
This should not have worked. Images need to be pulled from registry by Kubernetes. You need to push your image first to docker hub, or use the trueberryless/kub-first-app image.
First delete the previous deployment
kubectl delete deployment first-app
then create the new deployment
kubectl create deployment first-app --image=trueberryless/kub-first-app
minikube dashboard
Expose a port
kubectl expose deployment first-app --type=LoadBalancer --port=8080
See services
kubectl get services

Local Kubernetes

On a cloud infrastructure we would get an external IP. For minikube we need:
minikube service first-app
You can crash the app by going to the /error route. You will see the pod gets restarted automatically (taking longer and longer each time).
You can also scale your deployment
kubectl scale deployment/first-app --replicas=3
Have a look at your pods again
kubectl get pods
You can update your deployment by running. Images will only be pulled if they have a different tag.
kubectl set image deployment/first-app kub-first-app=trueberryless/kub-first-app:v2
view the deployment status
kubectl rollout status deployment/first-app
Run a deployment with a non-existing image/tag.
kubectl set image deployment/first-app kub-first-app=trueberryless/kub-first-app:not-exist
Checking the status of your rollout you will see, the old pods won’t be terminated because the new ones can’t be started due to an image pulling error.
Rollout to last deployment
kubectl rollout undo deployment/first-app
See deployment history
kubectl rollout history deployment/first-app
kubectl rollout history deployment/first-app --revision=3
You can also rollback to a specific revision
kubectl rollout undo deployment/first-app --to-revision=1

Command	Explanation	Use-Case
minikube status	Making sure, cluster is running	—
git commit -m	Create new commit with message-flag	—
git branch newBranch	Creates a new branch	Here: creates ‘newBranch’
git checkout newBranch	Move to other branch	Here: moves to ‘newBranch’
git merge newBranch	Combines two branches	Here: combining ‘newBranch’ & ‘main’
git rebase main	Moves commits from current branch in other branch - new linear history	Here: combining ‘newBranch’ & ‘main’

Second-Brain