1_demo_recreate

Recreate

Demo shows the recreate deployment strategy with Kubernetes.

Prereq

Get the images to docker hub:

make docker_deploy

Notice: You need to change DOCKER_PROJECT_ID in Makefile.

Demo

Notice: it causes downtime.

minikube start
kubectl config use-context minikube

kubectl apply -f kube-api-service.yaml

# deployment
kubectl apply -f kube-demo-api.yaml

# notice, it takes longer time due to the initialDelaySeconds
kubectl get po

# get the port our service is exposed on by minikube
export SVC_PORT=$(kubectl get service demo-api --output='jsonpath="{.spec.ports[0].nodePort}"' | tr -d '"')

# check whether it is correct:
curl $(minikube ip):${SVC_PORT}

# run curl in an endless loop to
# see the changes from the user perspective:
watch -n0.3 -x curl -s $(minikube ip):${SVC_PORT}

# observe
watch -n0.3 -x kubectl get po

# let's get from 1.0.0 to 2.0.0
kubectl set image  deployment/demo-api app=wojciech11/api-status:2.0.0


# notice: beacause of the initialDelaySeconds readiness and liveness probes
# we need to wait longer

Notice:

We would also change the version in kube-demo-api.yaml to 2.0.0 and use kube apply -f kube-demo-api.yaml.