helloworld-go

Simple hello world go web application that can be deployed to a Kubernetes cluster with Istio Service Mesh.

Build

go build

Run

./helloworld-go

Test Local

$ curl localhost:8080/api/v1/message
Go is the best language in the world

Docker

docker build . -t helloworld-go

Run Docker Container

docker run -p 8080:8080 helloworld-go

Test Docker Container

$ curl localhost:8080/api/v1/message
Go is the best language in the world

Tag and Push Docker Image

$ docker tag helloworld-go:1.0 nickdala/helloworld-go:1.0

$ docker push nickdala/helloworld-go:1.0

Deploy to Kubernetes

kubectl apply -f kubernetes/helloworld-v1.yaml

Gateway

To allow ‘ingress' traffic to reach the mesh we need to create a ‘Gateway' (to configure a load balancer) and a ‘VirtualService' (which controls the forwarding of traffic from the gateway to our services).

kubectl apply -f kubernetes/helloworld-all-v1.yaml

kubectl get services
kubectl get pods

Get the gateway external IP

kubectl get svc istio-ingressgateway -n istio-system

export GATEWAY_URL=<EXTERNAL IP>

$ curl -o /dev/null -s -w "%{http_code}\n" http://${GATEWAY_URL}/api/v1/message
200

$ curl http://${GATEWAY_URL}/api/v1/message
Go is the best language in the world

while :; do curl http://$GATEWAY_URL/api/v1/message; sleep 2; done

Change the message and deploy version 2

docker build . -t helloworld-go:2.0
docker tag helloworld-go:2.0 nickdala/helloworld-go:2.0
docker push nickdala/helloworld-go:2.0

kubectl apply -f helloworld-v2.yaml
kubectl apply -f helloworld-50-50.yaml

while :; do curl http://$GATEWAY_URL/api/v1/message; sleep 2; done

You should see alternating message. This is because 50% of the requests are routed to v1 of the service and the other 50% of the traffic is routed to v2.

Go is the best language in the world
Go is the best language in the world
Go is the best language in the world
Scala is the best language in the world
Scala is the best language in the world
Go is the best language in the world
Scala is the best language in the world