From 9d55fa7f46d48425a3aed739875d198f600445fb Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Fri, 21 Feb 2014 14:45:40 -0800
Subject: [PATCH] communicator/ssh: set TCP keep-alive [GH-872]

---
 CHANGELOG.md                | 1 +
 communicator/ssh/connect.go | 9 ++++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1e5eae8f8..0f9e285c2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@ BUG FIXES:
   checksum type is "none"
 * builder/virtualbox,vmware/qemu: Support for additional scancodes for
   `boot_command` such as `<up>`, `<left>`, `<insert>`, etc. [GH-808]
+* communicator/ssh: Send TCP keep-alives on connections. [GH-872]
 * provisioners/ansible-local: Properly upload custom playbooks. [GH-829]
 
 ## 0.5.1 (01/02/2014)
diff --git a/communicator/ssh/connect.go b/communicator/ssh/connect.go
index 00002dc70..bee446baa 100644
--- a/communicator/ssh/connect.go
+++ b/communicator/ssh/connect.go
@@ -10,6 +10,13 @@ import (
 // is suitable for use with the SSH communicator configuration.
 func ConnectFunc(network, addr string) func() (net.Conn, error) {
 	return func() (net.Conn, error) {
-		return net.DialTimeout(network, addr, 15*time.Second)
+		c, err := net.DialTimeout(network, addr, 15*time.Second)
+		if err != nil {
+			return nil, err
+		}
+
+		if tcpConn, ok := c.(*net.TCPConn); ok {
+			tcpConn.SetKeepAlive(true)
+		}
 	}
 }