From 32a205dc231f4c18af6b86590f67a83b40004098 Mon Sep 17 00:00:00 2001
From: Stephen Searles <stephen.searles@emssoftware.com>
Date: Wed, 28 Feb 2018 17:14:54 -0500
Subject: [PATCH] nsqlookupd: Main returns error

---
 apps/nsqlookupd/nsqlookupd.go |  6 +++++-
 nsqlookupd/nsqlookupd.go      | 13 ++++++++-----
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/apps/nsqlookupd/nsqlookupd.go b/apps/nsqlookupd/nsqlookupd.go
index c70a48fec..9fcc06c0e 100644
--- a/apps/nsqlookupd/nsqlookupd.go
+++ b/apps/nsqlookupd/nsqlookupd.go
@@ -77,7 +77,11 @@ func (p *program) Start() error {
 	options.Resolve(opts, flagSet, cfg)
 	daemon := nsqlookupd.New(opts)
 
-	daemon.Main()
+	err := daemon.Main()
+	if err != nil {
+		log.Fatalf("ERROR: failed to start nsqlookupd: %v", err)
+	}
+
 	p.nsqlookupd = daemon
 	return nil
 }
diff --git a/nsqlookupd/nsqlookupd.go b/nsqlookupd/nsqlookupd.go
index ffdbf85c3..d2dcd0928 100644
--- a/nsqlookupd/nsqlookupd.go
+++ b/nsqlookupd/nsqlookupd.go
@@ -1,6 +1,7 @@
 package nsqlookupd
 
 import (
+	"fmt"
 	"log"
 	"net"
 	"os"
@@ -42,18 +43,18 @@ func New(opts *Options) *NSQLookupd {
 	return n
 }
 
-func (l *NSQLookupd) Main() {
+// Main starts an instance of nsqlookupd and returns an
+// error if there was a problem starting up.
+func (l *NSQLookupd) Main() error {
 	ctx := &Context{l}
 
 	tcpListener, err := net.Listen("tcp", l.opts.TCPAddress)
 	if err != nil {
-		l.logf(LOG_FATAL, "listen (%s) failed - %s", l.opts.TCPAddress, err)
-		os.Exit(1)
+		return fmt.Errorf("listen (%s) failed - %s", l.opts.TCPAddress, err)
 	}
 	httpListener, err := net.Listen("tcp", l.opts.HTTPAddress)
 	if err != nil {
-		l.logf(LOG_FATAL, "listen (%s) failed - %s", l.opts.HTTPAddress, err)
-		os.Exit(1)
+		return fmt.Errorf("listen (%s) failed - %s", l.opts.TCPAddress, err)
 	}
 
 	l.tcpListener = tcpListener
@@ -67,6 +68,8 @@ func (l *NSQLookupd) Main() {
 	l.waitGroup.Wrap(func() {
 		http_api.Serve(httpListener, httpServer, "HTTP", l.logf)
 	})
+
+	return nil
 }
 
 func (l *NSQLookupd) RealTCPAddr() *net.TCPAddr {