From 5b07ef5ffe9d27b62a2071b4c9546d053a34c11a Mon Sep 17 00:00:00 2001
From: Kirill Zaitsev <kirik910@gmail.com>
Date: Sat, 20 Dec 2014 17:26:33 +0300
Subject: [PATCH] Automatically detect ENV variables

---
 cli/build.go | 26 +++++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/cli/build.go b/cli/build.go
index 5dd6f77f..c14fb09f 100644
--- a/cli/build.go
+++ b/cli/build.go
@@ -43,17 +43,17 @@ func NewBuildCommand() cli.Command {
 			},
 			cli.StringFlag{
 				Name:  "docker-host",
-				Value: "",
+				Value: getHost(),
 				Usage: "docker daemon address",
 			},
 			cli.StringFlag{
 				Name:  "docker-cert",
-				Value: "",
+				Value: getCert(),
 				Usage: "docker daemon tls certificate",
 			},
 			cli.StringFlag{
 				Name:  "docker-key",
-				Value: "",
+				Value: getKey(),
 				Usage: "docker daemon tls key",
 			},
 		},
@@ -204,3 +204,23 @@ func run(path, identity, dockerhost, dockercert, dockerkey string, publish, depl
 
 	return builder.BuildState.ExitCode, nil
 }
+
+func getHost() string {
+	return os.Getenv("DOCKER_HOST")
+}
+
+func getCert() string {
+	if os.Getenv("DOCKER_CERT_PATH") != "" && os.Getenv("DOCKER_TLS_VERIFY") == "1" {
+		return filepath.Join(os.Getenv("DOCKER_CERT_PATH"), "cert.pem")
+	} else {
+		return ""
+	}
+}
+
+func getKey() string {
+	if os.Getenv("DOCKER_CERT_PATH") != "" && os.Getenv("DOCKER_TLS_VERIFY") == "1" {
+		return filepath.Join(os.Getenv("DOCKER_CERT_PATH"), "key.pem")
+	} else {
+		return ""
+	}
+}