Dockerfile

FROM golang:latest
RUN mkdir /app
ADD . /app/
WORKDIR /app
RUN go build -o helloworld .
CMD ["/app/helloworld"]

main.go

package main

import (
	"flag"
	"fmt"
	"log"
	"net/http"
)

func handler(w http.ResponseWriter, r *http.Request) {
	log.Print("Hello world received a request.")
	fmt.Fprintln(w, "Hello World! How about some tasty noodles?")
}

func main() {
	flag.Parse()
	log.Print("Hello world app started.")

	http.HandleFunc("/", handler)
	http.ListenAndServe(":8080", nil)
}