From 9e413d8d01b2c76585d82f08e1b363dc4c2d141c Mon Sep 17 00:00:00 2001
From: Tom Wilkie <tom.wilkie@gmail.com>
Date: Wed, 8 May 2019 09:30:09 +0100
Subject: [PATCH] Allow user to specify HTTP and gRPC bind addresses (not just
 ports.)

This allows us to use 'localhost' in tests, and prevents an 'Allow connections from...' dialog on MacOS when running unit tests.

Signed-off-by: Tom Wilkie <tom.wilkie@gmail.com>
---
 server/server.go      | 8 ++++++--
 server/server_test.go | 7 +++++++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/server/server.go b/server/server.go
index 38ca7cfe..8fb3b155 100644
--- a/server/server.go
+++ b/server/server.go
@@ -28,7 +28,9 @@ import (
 // Config for a Server
 type Config struct {
 	MetricsNamespace string `yaml:"-"`
+	HTTPListenHost   string `yaml:"http_listen_host"`
 	HTTPListenPort   int    `yaml:"http_listen_port"`
+	GRPCListenHost   string `yaml:"grpc_listen_host"`
 	GRPCListenPort   int    `yaml:"grpc_listen_port"`
 
 	RegisterInstrumentation bool `yaml:"register_instrumentation"`
@@ -56,7 +58,9 @@ type Config struct {
 
 // RegisterFlags adds the flags required to config this to the given FlagSet
 func (cfg *Config) RegisterFlags(f *flag.FlagSet) {
+	f.StringVar(&cfg.HTTPListenHost, "server.http-listen-host", "", "HTTP server listen host.")
 	f.IntVar(&cfg.HTTPListenPort, "server.http-listen-port", 80, "HTTP server listen port.")
+	f.StringVar(&cfg.GRPCListenHost, "server.grpc-listen-host", "", "gRPC server listen host.")
 	f.IntVar(&cfg.GRPCListenPort, "server.grpc-listen-port", 9095, "gRPC server listen port.")
 	f.BoolVar(&cfg.RegisterInstrumentation, "server.register-instrumentation", true, "Register the intrumentation handlers (/metrics etc).")
 	f.DurationVar(&cfg.ServerGracefulShutdownTimeout, "server.graceful-shutdown-timeout", 30*time.Second, "Timeout for graceful shutdowns")
@@ -88,12 +92,12 @@ type Server struct {
 // New makes a new Server
 func New(cfg Config) (*Server, error) {
 	// Setup listeners first, so we can fail early if the port is in use.
-	httpListener, err := net.Listen("tcp", fmt.Sprintf(":%d", cfg.HTTPListenPort))
+	httpListener, err := net.Listen("tcp", fmt.Sprintf("%s:%d", cfg.HTTPListenHost, cfg.HTTPListenPort))
 	if err != nil {
 		return nil, err
 	}
 
-	grpcListener, err := net.Listen("tcp", fmt.Sprintf(":%d", cfg.GRPCListenPort))
+	grpcListener, err := net.Listen("tcp", fmt.Sprintf("%s:%d", cfg.GRPCListenHost, cfg.GRPCListenPort))
 	if err != nil {
 		return nil, err
 	}
diff --git a/server/server_test.go b/server/server_test.go
index aedbeaa3..f27ac3b7 100644
--- a/server/server_test.go
+++ b/server/server_test.go
@@ -36,6 +36,9 @@ func (f FakeServer) Succeed(ctx context.Context, req *google_protobuf.Empty) (*g
 func TestErrorInstrumentationMiddleware(t *testing.T) {
 	var cfg Config
 	cfg.RegisterFlags(flag.NewFlagSet("", flag.ExitOnError))
+	cfg.HTTPListenHost = "localhost"
+	cfg.HTTPListenPort = 9190
+	cfg.GRPCListenHost = "localhost"
 	cfg.GRPCListenPort = 1234
 	server, err := New(cfg)
 	require.NoError(t, err)
@@ -102,7 +105,9 @@ func TestErrorInstrumentationMiddleware(t *testing.T) {
 
 func TestRunReturnsError(t *testing.T) {
 	cfg := Config{
+		HTTPListenHost: "localhost",
 		HTTPListenPort: 9190,
+		GRPCListenHost: "localhost",
 		GRPCListenPort: 9191,
 	}
 	t.Run("http", func(t *testing.T) {
@@ -142,7 +147,9 @@ func TestMiddlewareLogging(t *testing.T) {
 	var level logging.Level
 	level.Set("info")
 	cfg := Config{
+		HTTPListenHost:   "localhost",
 		HTTPListenPort:   9192,
+		GRPCListenHost:   "localhost",
 		HTTPMiddleware:   []middleware.Interface{middleware.Logging},
 		MetricsNamespace: "testing_logging",
 		LogLevel:         level,