Key features of GCP - Google Kubernetes Engine (GKE)

- Orchestration

- Auto Scaling - Scale containers based on demand

- Service Discovery - Help microservices find one another

- Load Balancer - Distribute load among multiple instances of a microservice

- Self Healing - Do health checks and replace failing instances

- Zero Downtime Deployments - Release new versions without downtime

1. You can pull docker image to your OWN local machine

   -Exchange microservice 
   
   docker pull jamesfloatingmarket1508/mss-currency-exchange-k8s:0.0.11-SNAPSHOT
   
   - Conversion microservice
   docker pull jamesfloatingmarket1508/mss-currency-conversion-k8s:0.0.11-SNAPSHOT
   

2. Run docker containers in your local manchine by Docker Deamon, for testing before doing any deployment.

   docker run -p 8000:8000 jamesfloatingmarket1508/mss-currency-exchange-k8s:0.0.11-SNAPSHOT
   
   docker run -p 8100:8100 jamesfloatingmarket1508/mss-currency-conversion-k8s:0.0.11-SNAPSHOT
   

3. Test command on local:

    curl http://localhost:8000/currency-exchange/from/USD/to/GBP
   
    curl  http://localhost:8100/feign/currency-conversion/from/USD/to/GBP/quanlity/70
   

Create trial Google Kubernetes Cluster

Step 1: Make sure you have GCloud be installed in your PC.

https://cloud.google.com/sdk/docs/install

Step 2: Authentication with Google Account that has Kubernetes Cluster.

gcloud container clusters get-credentials {your cluster name} --zone us-central1-c --project {project id}

a) Manual:

a1) Exchange service

kubectl create deployment currency-exchange --image=jamesfloatingmarket1508/mss-currency-exchange-k8s:0.0.11-SNAPSHOT

kubectl expose deployment currency-exchange --type=LoadBalancer --port=8000

Terminal run:  kubectl get service

Test again: curl http://EXTERNAL-IP:port/currency-exchange/from/USD/to/GBP

Public IP: curl http://34.31.250.64:8000/currency-exchange/from/USD/to/GBP

a2) Conversion service

kubectl create deployment currency-conversion --image=jamesfloatingmarket1508/mss-currency-conversion-k8s:0.0.11-SNAPSHOT

kubectl expose deployment currency-conversion --type=LoadBalancer --port=8100

curl http://35.202.191.27:8100/feign/currency-conversion/from/USD/to/GBP/quanlity/123

b) How about deploy automatic by yaml file to Google Kubernetes Engine Open Terminal

Step 1)

 cd to exchange-currency-k8s directory
 kubectl apply -f deployment.yaml

Step 2)

cd to conversion-currency-k8s directory
kubectl apply -f deployment.yaml

kubectl get hpa

kubectl top node

kubectl top pods

kubectl get pods --all-namespaces

• Stress test ping API every 0.01 second to make the CPU usage hits 20%

  watch -n 0.01  curl http://35.202.191.27:8100/feign/currency-conversion/from/USD/to/GBP/quanlity/123
  
  watch -n 0.01  curl http://35.202.191.27:8100/feign/currency-conversion/from/USD/to/GBP/quanlity/456
  
  watch -n 0.01  curl http://35.202.191.27:8100/feign/currency-conversion/from/USD/to/GBP/quanlity/789
  

Auto Scaling down to default replica set 1.