# Create a deployment for each container in the demo system
kubectl run html-frontend --image=dalealleshouse/html-frontend:1.0 --port=80\
  --env STATUS_HOST=k8-master:31111 --labels="app=html-frontend"
kubectl run java-consumer --image=dalealleshouse/java-consumer:1.0
kubectl run ruby-producer --image=dalealleshouse/ruby-producer:1.0 
kubectl run status-api --image=dalealleshouse/status-api:1.0 port=5000 \
  --labels="app=status-api"
kubectl run queue --image=arm32v6/rabbitmq:3.7-management-alpine

# View the pods created by the deployments
kubectl get pods

# Run docker type commands on the containers
kubectl exec -it *POD_NAME* bash
kubectl logs *POD_NAME*

# Notice the java-consumer cannot connect to the queue
kubectl get logs *java-consumer-pod*

# The following command makes the queue discoverable via the name queue
kubectl expose deployment queue --port=15672,5672 --name=queue

# Running the command again shows that it is connected now
kubectl get logs *java-consumer-pod*

# Create an endpoint for the HTML page as the REST API Service
kubectl create service nodeport html-frontend --tcp=80:80 --node-port=31112
kubectl create service nodeport status-api --tcp=80:5000 --node-port=31111

# Delete all objects made previously
# Each object has a matching file in the kube directory
kubectl delete -f kube/

# Recreate everything
kubectl create -f kube/

# configuration specific - most cloud providers have something similar
# create a tunnel from the cluster to the local machine
kubectl proxy

# Get the authentication token
kubectl -n kube-system describe secret $(kubectl -n kube-system get secret | \
grep admin-user | awk '{print $1}')

# Scale the NGINX deployment to 3 replicas
kubectl scale deployment html-frontend --replicas=3

# Maintain between 1 and 5 replicas based on CPU usage
kubectl autoscale deployment java-consumer --min=1 --max=5 --cpu-percent=50

# Run this repeatedly to see # of replicas created
# Also, the "In Process" number on the web page will reflect the number of replicas
kubectl get deployments

# Find nodes running html-frontend
kubectl describe nodes | grep -E 'html-frontend|Name:'

# Simulate a failure by unplugging a network cable

# Pods are automatically regenerated
kubectl get pods

# Find front end pod
kubectl get pods
# Simulate a failure by manually deleting the health check file
kubectl exec *POD_NAME* rm /usr/share/nginx/html/healthz.html
# Notice the restart
kubectl get pods
# See the restart in the event log
kubectl get events | grep *POD_NAME*

...
        livenessProbe:
          httpGet:
            path: /healthz.html
            port: 80
          initialDelaySeconds: 3
          periodSeconds: 2
        readinessProbe:
          httpGet:
            path: /healthz.html
            port: 80
          initialDelaySeconds: 3
          periodSeconds: 2

# Update the image on the deployment
kubectl set image deployment/html-frontend html-frontend=dalealleshouse/html-frontend:2.0

# Run repeadly to see the number of available replicas
kubectl get deployments

# Roll back the deployment to the old image
kubectl rollout undo deployment html-frontend