From 1d617f1b92c79196ecae47694b2bcbe75d3fb683 Mon Sep 17 00:00:00 2001
From: Josh Curl <josh@curl.me>
Date: Mon, 21 Nov 2016 15:18:44 -0800
Subject: [PATCH] Remove empty Docker engine arguments

---
 config/docker_config.go      |  8 ++++++--
 config/docker_config_test.go | 14 ++++++++++++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/config/docker_config.go b/config/docker_config.go
index ec600158..92f2fe10 100644
--- a/config/docker_config.go
+++ b/config/docker_config.go
@@ -43,11 +43,15 @@ func generateEngineOptsSlice(opts EngineOpts) []string {
 			}
 		case []string:
 			for _, elem := range value {
-				optsSlice = append(optsSlice, fmt.Sprintf("--%s", optTag), elem)
+				if elem != "" {
+					optsSlice = append(optsSlice, fmt.Sprintf("--%s", optTag), elem)
+				}
 			}
 		case map[string]string:
 			for k, v := range value {
-				optsSlice = append(optsSlice, fmt.Sprintf("--%s", optTag), fmt.Sprintf("%s=%s", k, v))
+				if v != "" {
+					optsSlice = append(optsSlice, fmt.Sprintf("--%s", optTag), fmt.Sprintf("%s=%s", k, v))
+				}
 			}
 		}
 	}
diff --git a/config/docker_config_test.go b/config/docker_config_test.go
index adccf21b..750c57e4 100644
--- a/config/docker_config_test.go
+++ b/config/docker_config_test.go
@@ -18,6 +18,20 @@ func TestGenerateEngineOptsString(t *testing.T) {
 	if len(generateEngineOptsSlice(EngineOpts{})) != 0 {
 		t.Fail()
 	}
+	if len(generateEngineOptsSlice(EngineOpts{
+		Host: []string{
+			"",
+		},
+	})) != 0 {
+		t.Fail()
+	}
+	if len(generateEngineOptsSlice(EngineOpts{
+		LogOpts: map[string]string{
+			"max-file": "",
+		},
+	})) != 0 {
+		t.Fail()
+	}
 
 	testContains(t, fmt.Sprint(generateEngineOptsSlice(EngineOpts{
 		Bridge: "bridge",