[FAB-1174] set orderer config path via env var

use ORDERER_CONFIG_PATH env var to set
path to orderer.yaml

Change-Id: I5b179352d5fec1ff7331bfee20af71f92bc571e7
Signed-off-by: tuand27613 <tdang@us.ibm.com>

images/orderer/Dockerfile.in

@@ -1,7 +1,7 @@
 FROM hyperledger/fabric-baseimage:_BASE_TAG_
+ENV ORDERER_CFG_PATH /etc/hyperledger/fabric
 RUN mkdir -p /var/hyperledger/db /etc/hyperledger/fabric
 COPY payload/orderer /usr/local/bin
-COPY payload/orderer.yaml /etc/hyperledger/fabric
-WORKDIR /etc/hyperledger/fabric
+COPY payload/orderer.yaml $ORDERER_CFG_PATH
 EXPOSE 7050
 CMD orderer

orderer/config/config.go

@@ -192,25 +192,30 @@ func (c *TopLevel) completeInitialization() {
 func Load() *TopLevel {
 	config := viper.New()
 
+	config.SetConfigName("orderer")
+	alternativeCfgPath := os.Getenv("ORDERER_CFG_PATH")
+	if alternativeCfgPath != "" {
+		logger.Infof("User defined config file path: %s", alternativeCfgPath)
+		config.AddConfigPath(alternativeCfgPath) // Path to look for the config file in
+	} else {
+		config.AddConfigPath("./")
+		config.AddConfigPath("../../.")
+		config.AddConfigPath("../orderer/")
+		config.AddConfigPath("../../orderer/")
+		// Path to look for the config file in based on GOPATH
+		gopath := os.Getenv("GOPATH")
+		for _, p := range filepath.SplitList(gopath) {
+			ordererPath := filepath.Join(p, "src/github.com/hyperledger/fabric/orderer/")
+			config.AddConfigPath(ordererPath)
+		}
+	}
+
 	// for environment variables
 	config.SetEnvPrefix(Prefix)
 	config.AutomaticEnv()
 	replacer := strings.NewReplacer(".", "_")
 	config.SetEnvKeyReplacer(replacer)
 
-	config.SetConfigName("orderer")
-	config.AddConfigPath("./")
-	config.AddConfigPath("../../.")
-	config.AddConfigPath("../orderer/")
-	config.AddConfigPath("../../orderer/")
-	config.AddConfigPath("/etc/hyperledger/fabric/")
-	// Path to look for the config file in based on GOPATH
-	gopath := os.Getenv("GOPATH")
-	for _, p := range filepath.SplitList(gopath) {
-		ordererPath := filepath.Join(p, "src/github.com/hyperledger/fabric/orderer/")
-		config.AddConfigPath(ordererPath)
-	}
-
 	err := config.ReadInConfig()
 	if err != nil {
 		panic(fmt.Errorf("Error reading %s plugin config: %s", Prefix, err))