From 3756bbae901a299d04df407c440333a956493d67 Mon Sep 17 00:00:00 2001
From: Darren Shepherd <darren@rancher.com>
Date: Wed, 18 Mar 2015 06:22:19 -0700
Subject: [PATCH] Reliably merge the yaml maps data

---
 config/config_test.go | 97 ++++++++++++++++++++++++++++++++++++++++++-
 config/disk.go        | 16 +++++--
 util/util.go          | 18 ++++++++
 3 files changed, 126 insertions(+), 5 deletions(-)

diff --git a/config/config_test.go b/config/config_test.go
index c19a346a..65705917 100644
--- a/config/config_test.go
+++ b/config/config_test.go
@@ -1,6 +1,12 @@
 package config
 
-import "testing"
+import (
+	"fmt"
+	"log"
+	"testing"
+
+	"github.com/rancherio/os/util"
+)
 import "reflect"
 
 func TestParseCmdline(t *testing.T) {
@@ -93,3 +99,92 @@ func TestSet(t *testing.T) {
 		t.Fatalf("Expected %v, got %v", expected, data)
 	}
 }
+
+type OuterData struct {
+	One Data `"yaml:one"`
+}
+
+type Data struct {
+	Two   bool `"yaml:two"`
+	Three bool `"yaml:three"`
+}
+
+func TestMapMerge(t *testing.T) {
+	one := `
+one:
+  two: true`
+	two := `
+one:
+  three: true`
+
+	data := make(map[string]map[string]bool)
+	yaml.Unmarshal([]byte(one), data)
+	yaml.Unmarshal([]byte(two), data)
+
+	if _, ok := data["one"]; !ok {
+		t.Fatal("one not found")
+	}
+
+	if !data["one"]["three"] {
+		t.Fatal("three not found")
+	}
+
+	if data["one"]["two"] {
+		t.Fatal("two not found")
+	}
+
+	data2 := &OuterData{}
+	yaml.Unmarshal([]byte(one), data2)
+	yaml.Unmarshal([]byte(two), data2)
+
+	if !data2.One.Three {
+		t.Fatal("three not found")
+	}
+
+	if !data2.One.Two {
+		t.Fatal("two not found")
+	}
+
+}
+
+func TestUserDocker(t *testing.T) {
+	config := &Config{
+		UserDocker: DockerConfig{
+			TLS: true,
+		},
+	}
+
+	bytes, err := yaml.Marshal(config)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	config = NewConfig()
+	err = yaml.Unmarshal(bytes, config)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	data := make(map[interface{}]interface{})
+	util.Convert(config, data)
+
+	fmt.Println(data)
+
+	val, ok := data["user_docker"]
+	if !ok {
+		t.Fatal("Failed to find user_docker")
+	}
+
+	if m, ok := val.(map[interface{}]interface{}); ok {
+		if v, ok := m["tls"]; ok {
+			if v != true {
+				t.Fatal("user_docker.tls is not true")
+			}
+		} else {
+			t.Fatal("user_docker.tls is not found")
+		}
+	} else {
+		t.Fatal("Bad data")
+	}
+
+}
diff --git a/config/disk.go b/config/disk.go
index c2d35601..c0d34541 100644
--- a/config/disk.go
+++ b/config/disk.go
@@ -62,26 +62,34 @@ func readSavedConfig(bytes []byte) (map[interface{}]interface{}, error) {
 }
 
 func readConfig(bytes []byte, files ...string) (map[interface{}]interface{}, error) {
-	data := make(map[interface{}]interface{})
+	// You can't just overlay yaml bytes on to maps, it won't merge, but instead
+	// just override the keys and not merge the map values.
+	left := make(map[interface{}]interface{})
 	for _, conf := range files {
 		content, err := readConfigFile(conf)
 		if err != nil {
 			return nil, err
 		}
 
-		err = yaml.Unmarshal(content, &data)
+		right := make(map[interface{}]interface{})
+		err = yaml.Unmarshal(content, &right)
 		if err != nil {
 			return nil, err
 		}
+
+		util.MergeMaps(left, right)
 	}
 
 	if bytes != nil && len(bytes) > 0 {
-		if err := yaml.Unmarshal(bytes, &data); err != nil {
+		right := make(map[interface{}]interface{})
+		if err := yaml.Unmarshal(bytes, &right); err != nil {
 			return nil, err
 		}
+
+		util.MergeMaps(left, right)
 	}
 
-	return data, nil
+	return left, nil
 }
 
 func readConfigFile(file string) ([]byte, error) {
diff --git a/util/util.go b/util/util.go
index 2d859307..36c49257 100644
--- a/util/util.go
+++ b/util/util.go
@@ -164,3 +164,21 @@ func Convert(from, to interface{}) error {
 
 	return yaml.Unmarshal(bytes, to)
 }
+
+func MergeMaps(left, right map[interface{}]interface{}) {
+	for k, v := range right {
+		merged := false
+		if existing, ok := left[k]; ok {
+			if rightMap, ok := v.(map[interface{}]interface{}); ok {
+				if leftMap, ok := existing.(map[interface{}]interface{}); ok {
+					merged = true
+					MergeMaps(leftMap, rightMap)
+				}
+			}
+		}
+
+		if !merged {
+			left[k] = v
+		}
+	}
+}