use environment variables for hostnames and ports

relayserver/RelayServer.cpp

@@ -11,16 +11,18 @@ int RelayServer::Run()
 	uWS::Hub h;
 	EPoll epoll;
 
-	_clientSocket = socket(AF_INET, SOCK_STREAM, 0);
-	struct sockaddr_in serv_addr;
-	serv_addr.sin_family = AF_INET;
-	serv_addr.sin_port = htons(9010);
-	inet_pton(AF_INET, "127.0.0.1", &serv_addr.sin_addr);
-	if (connect(_clientSocket, (struct sockaddr*)&serv_addr, sizeof(serv_addr))<0)
+	const char* gameserverHost = getEnvOrDefault(ENV_GAMESERVER_HOST, ENV_GAMESERVER_HOST_DEFAULT);
+	const char* gameserverPort = getEnvOrDefault(ENV_GAMESERVER_PORT, ENV_GAMESERVER_PORT_DEFAULT);
+	const char* websocketPort = getEnvOrDefault(ENV_WEBSOCKET_PORT, ENV_WEBSOCKET_PORT_DEFAULT);
+
+	fprintf(stderr, "connecting to gameserver on %s port %s...\n", gameserverHost , gameserverPort);
+	_clientSocket = connectTcpSocket(gameserverHost , gameserverPort);
+	if (_clientSocket < 0)
 	{
 		perror("connect to server failed");
 		return -1;
 	}
+	fprintf(stderr, "connected.\n");
 
 	_tcpProtocol.SetFrameCompleteCallback(
 		[this, &h](uint64_t frame_id)
@@ -62,7 +64,7 @@ int RelayServer::Run()
 		res->end(response.data(), response.length());
 	});
 
-	if (!h.listen(9009))
+	if (!h.listen(atoi(websocketPort)))
 	{
 		return -1;
 	}
@@ -86,3 +88,47 @@ int RelayServer::Run()
 		);
 	}
 }
+
+int RelayServer::connectTcpSocket(const char *hostname, const char *port)
+{
+	struct addrinfo hints;
+	memset(&hints, 0, sizeof(struct addrinfo));
+	hints.ai_family = AF_UNSPEC;    /* Allow IPv4 or IPv6 */
+	hints.ai_socktype = SOCK_STREAM; /* Datagram socket */
+
+	struct addrinfo *result;
+	int s = getaddrinfo(hostname, port, &hints, &result);
+	if (s != 0)
+	{
+		fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(s));
+		return s;
+	}
+
+	struct addrinfo* rp = nullptr;
+	int retval = -1;
+	for (rp=result; rp!=nullptr; rp=rp->ai_next)
+	{
+		int fd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
+		if (fd == -1) { continue; }
+
+		if (connect(fd, rp->ai_addr, rp->ai_addrlen) == 0)
+		{
+			retval = fd;
+			break;
+		}
+		close(fd);
+	}
+
+	freeaddrinfo(result);
+	return retval;
+}
+
+const char *RelayServer::getEnvOrDefault(const char *envVar, const char *defaultValue)
+{
+	const char* value = getenv(envVar);
+	if (value == nullptr)
+	{
+		value = defaultValue;
+	}
+	return value;
+}

relayserver/RelayServer.h

@@ -12,4 +12,13 @@ class RelayServer
 	private:
 		int _clientSocket;
 		TcpProtocol _tcpProtocol;
+
+		static constexpr const char* ENV_GAMESERVER_HOST = "GAMESERVER_HOST";
+		static constexpr const char* ENV_GAMESERVER_HOST_DEFAULT = "localhost";
+		static constexpr const char* ENV_GAMESERVER_PORT = "GAMESERVER_PORT";
+		static constexpr const char* ENV_GAMESERVER_PORT_DEFAULT = "9010";
+		static constexpr const char* ENV_WEBSOCKET_PORT = "WEBSOCKET_PORT";
+		static constexpr const char* ENV_WEBSOCKET_PORT_DEFAULT = "9009";
+		static int connectTcpSocket(const char* hostname, const char* port);
+		static const char* getEnvOrDefault(const char* envVar, const char* defaultValue);
 };