hello

hello

A simple HTTP Server in Go that responds with a Hello to any request it gets.
It includes a counter, the server host name and the relative request URI in the response.

Multiple versions are available to facilitate Kubernetes experiments. The only difference is the language of the greeting.

The server listens for requests on port 80 for requests and in addition, liveness checks and readiness checks are availabe on port 8080.

Run locally

To start a local instance, simply run

go run main.go serve

Docker

You can start an instance using docker run, for example:

docker run -p 10080:80 -p 10880:8080 akleinloog/hello:v1

The server will then be available at http://localhost:10080, the liveness check at http://localhost:10880/alive and the readiness check at http://localhost:10880/ready.

To facilitate Kubernetes experiments you can toggle the liveness check by: http://localhost:10880/toggleAlive

And the readiness check by: http://localhost:10880/toggleReady

To customize the greeting:

docker run -p 10080:80 -p 10880:8080 -e GREETING='Hi' akleinloog/hello:v4

Docker-compose

You can also use a docker compose file, for example:

version: '3.7'

services:
  hello:
    container_name: hello
    image: akleinloog/hello:v1
    ports:
      - 10080:80
      - 10880:8080

Kubernetes Deployment

Deploy it to a Kubernetes cluster using kubectl:

kubectl create deployment helloapp --image=akleinloog/hello:v1

kubectl expose deployment helloapp --port=80 --type=LoadBalancer

Or use a Kubernetes deployment file like this:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: hello-app
spec:
  replicas: 3
  selector:
    matchLabels:
      app: hello-app
  template:
    metadata:
      labels:
        app: hello-app
        env: dev
    spec:
      containers:
      - name: hello-app
        image: akleinloog/hello:v1
        imagePullPolicy: Always
        resources:
          limits:
            memory: "128Mi"
            cpu: "200m"
        ports:
        - containerPort: 80

Don't forget the service:

apiVersion: v1
kind: Service
metadata:
  name: hello-service
spec:
  selector:
    app: hello-app
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80
  type: NodePort

Versions

v1: Hello

v2: Bonjour

v3: Aloha

v4: Customizable from Environment Variable GREETING, defaults to Hello

Version tagging

git tag -a v1 -m "Version 1 - English"

git push origin --tags