Port is now read from environment variables

cmd/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"strconv"
 
 	"github.com/gostream-official/artists/impl/funcs/createartist"
 	"github.com/gostream-official/artists/impl/funcs/deleteartist"
@@ -31,6 +32,17 @@ func init() {
 func main() {
 	log.Infof("booting service instance ...")
 
+	executionPortEnvVar := env.GetEnvironmentVariableWithFallback("PORT", "9871")
+	executionPort, err := strconv.Atoi(executionPortEnvVar)
+
+	if err != nil {
+		log.Fatalf("Received invalid execution port")
+	}
+
+	if executionPort < 0 || executionPort > 65535 {
+		log.Fatalf("Received invalid execution port")
+	}
+
 	mongoUsername, err := env.GetEnvironmentVariable("MONGO_USERNAME")
 	if err != nil {
 		log.Fatalf("Cannot retrieve mongo username via environment variable")
@@ -66,7 +78,7 @@ func main() {
 	engine.HandleWith("PUT", "/artists/:id", updateartist.Handler).Inject(injector)
 	engine.HandleWith("DELETE", "/artists/:id", deleteartist.Handler).Inject(injector)
 
-	err = engine.Run(9871)
+	err = engine.Run(uint16(executionPort))
 	if err != nil {
 		log.Fatalf("failed to launch router engine: %s", err)
 	}