Make the port number configurable

Signed-off-by: Oliver Davies <oliver@oliverdavies.uk>

go-api/main.go

@@ -3,7 +3,9 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"log"
 	"net/http"
+	"os"
 	"strconv"
 )
 
@@ -51,8 +53,24 @@ func getResponseCode(r *http.Request) int {
 	return http.StatusOK
 }
 
+func getPort() string {
+	port := os.Getenv("PORT")
+
+	if port != "" {
+		return port
+	}
+
+	return "8080"
+}
+
 func main() {
 	http.HandleFunc("/", handler)
 
-	http.ListenAndServe(":8080", nil)
+	addr := ":" + getPort()
+
+	fmt.Printf("Starting server on %s", addr)
+
+	if err := http.ListenAndServe(addr, nil); err != nil {
+		log.Fatal(err)
+	}
 }