Dockerfile Build, Certificate Generation, and Health Check

Dockerfile

@@ -1,12 +1,30 @@
+FROM golang:1.13-alpine3.10 AS build
+
+WORKDIR /go/src/app
+
+ARG CGO_ENABLED=0
+
+RUN apk --no-cache add ca-certificates git openssl && \
+    openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365 -nodes -subj "/CN=example.com"
+
+COPY . .
+
+RUN go get -d -v ./... && \
+    go build -ldflags "-s -w" -o ./echo-server ./cmd/echo-server
+
 FROM scratch
-COPY bin /bin
+
+WORKDIR /bin
+
+COPY --from=build /go/src/app/echo-server .
+COPY --from=build /go/src/app/cert.pem .
+COPY --from=build /go/src/app/key.pem .
 
 ENV PORT 8080
 ENV SSLPORT 8443
 
-EXPOSE 8080 8443
+EXPOSE "$PORT" "$SSLPORT"
 
 ENV ADD_HEADERS='{"X-Real-Server": "echo-server"}'
 
-WORKDIR /bin
 ENTRYPOINT ["/bin/echo-server"]

cmd/echo-server/main.go

@@ -24,7 +24,6 @@ func RunServer(addr string, sslAddr string, ssl map[string]string) chan error {
 		if err := http.ListenAndServe(addr, nil); err != nil {
             		errs <- err
         	}
-
 	}()
 
 	go func() {
@@ -70,18 +69,40 @@ var upgrader = websocket.Upgrader{
 }
 
 func handler(wr http.ResponseWriter, req *http.Request) {
-	fmt.Printf("%s | %s %s\n", req.RemoteAddr, req.Method, req.URL)
+	fmt.Printf("%s | %s | %s %s\n", req.RemoteAddr, req.UserAgent(), req.Method, req.URL)
 	if websocket.IsWebSocketUpgrade(req) {
 		serveWebSocket(wr, req)
-	} else if req.URL.Path == "/ws" {
+	}	else if req.URL.Path == "/ws" {
 		wr.Header().Add("Content-Type", "text/html")
 		wr.WriteHeader(200)
 		io.WriteString(wr, websocketHTML)
-	} else {
+	} else if req.URL.Path == "/health" {
+		healthEndpoint(wr, req)
+	}	else {
 		serveHTTP(wr, req)
 	}
 }
 
+func healthEndpoint(wr http.ResponseWriter, req *http.Request) {
+
+	// Health Check endpoint
+
+	type Health struct {
+		Status    string
+	}
+
+	health := Health{"ok"}
+
+	healthResponse, err := json.Marshal(health)
+	if err != nil {
+			panic(err)
+	}
+
+	wr.Header().Set("Content-Type", "application/json")
+	wr.Write(healthResponse)
+
+}
+
 func serveWebSocket(wr http.ResponseWriter, req *http.Request) {
 	connection, err := upgrader.Upgrade(wr, req, nil)
 	if err != nil {