Deploy, manage, and scale a simple Go web app on Kubernetes.

Dockerizing the Go application

Create a file named Dockerfile inside the project’s folder and add configurations in the Dockerfile.

Build and push the docker image of our Go app on docker hub so that we can later use this image while deploying the app on Kubernetes

$ docker build -t go-k8s .

$ docker tag go-kubernetes gyanchand1230/go-webapp:1.0.0

$ docker login

$ docker push gyanchand1230/go-webapp:1.0.0

It’s a simple yaml file with a bunch of configurations containing the desired state of application.

start a Kubernetes cluster: minikube start

Deploy our app to the minikube cluster by applying the deployment manifest using kubectl. kubectl apply -f k8s-deployment.yml

The deployment is created. You can get the deployments like this:

$ kubectl get deployments

to get the pods in the cluster:

$ kubectl get pods

Pods are allocated a private IP address by default and cannot be reached outside of the cluster. You can use the kubectl port-forward command to map a local port to a port inside the pod like this:

$ kubectl port-forward go-webapp-69b45499fb-7fh87 8080:8080

now interact with the Pod on the forwarded port:

$ curl localhost:8080/home

The port-forward command is good for testing the pods directly. But in production, we want to expose the pod using services.

The level of access the service provides to the set of pods depends on the service type which can be:

ClusterIP: Internal only.

NodePort: Gives each node an external IP that’s accessible from outside the cluster and also opens a Port. A kube-proxy component that runs on each node of the Kubernetes cluster listens for incoming traffic on the port and forwards them to the selected pods in a round-robin fashion.

LoadBalancer: Adds a load balancer from the cloud provider which forwards traffic from the service to the nodes within it.