server: Introduce a new env MINIO_REGION. (#4078)

This is implemented to be able to override region
through command line just like how access and
secret keys are provided.

cmd/config-v18.go

@@ -170,6 +170,10 @@ func newConfig() error {
 		srvCfg.SetBrowser(globalIsBrowserEnabled)
 	}
 
+	if globalIsEnvRegion {
+		srvCfg.SetRegion(globalServerRegion)
+	}
+
 	// hold the mutex lock before a new config is assigned.
 	// Save the new config globally.
 	// unlock the mutex.
@@ -295,10 +299,15 @@ func loadConfig() error {
 	if globalIsEnvCreds {
 		srvCfg.SetCredential(globalActiveCred)
 	}
+
 	if globalIsEnvBrowser {
 		srvCfg.SetBrowser(globalIsBrowserEnabled)
 	}
 
+	if globalIsEnvRegion {
+		srvCfg.SetRegion(globalServerRegion)
+	}
+
 	// hold the mutex lock before a new config is assigned.
 	serverConfigMu.Lock()
 	serverConfig = srvCfg
@@ -308,6 +317,9 @@ func loadConfig() error {
 	if !globalIsEnvBrowser {
 		globalIsBrowserEnabled = serverConfig.GetBrowser()
 	}
+	if !globalIsEnvRegion {
+		globalServerRegion = serverConfig.GetRegion()
+	}
 	serverConfigMu.Unlock()
 
 	return nil

cmd/config-v18_test.go

@@ -138,10 +138,10 @@ func TestServerConfigWithEnvs(t *testing.T) {
 	os.Setenv("MINIO_SECRET_KEY", "minio123")
 	defer os.Unsetenv("MINIO_SECRET_KEY")
 
-	defer func() {
-		globalIsEnvBrowser = false
-		globalIsEnvCreds = false
-	}()
+	os.Setenv("MINIO_REGION", "us-west-1")
+	defer os.Unsetenv("MINIO_REGION")
+
+	defer resetGlobalIsEnvs()
 
 	// Get test root.
 	rootPath, err := getTestRoot()
@@ -165,6 +165,11 @@ func TestServerConfigWithEnvs(t *testing.T) {
 		t.Errorf("Expecting browser is set to false found %v", serverConfig.GetBrowser())
 	}
 
+	// Check if serverConfig has
+	if serverConfig.GetRegion() != "us-west-1" {
+		t.Errorf("Expecting region to be \"us-west-1\" found %v", serverConfig.GetRegion())
+	}
+
 	// Check if serverConfig has
 	cred := serverConfig.GetCredential()
 
@@ -175,6 +180,7 @@ func TestServerConfigWithEnvs(t *testing.T) {
 	if cred.SecretKey != "minio123" {
 		t.Errorf("Expecting access key to be `minio123` found %s", cred.SecretKey)
 	}
+
 }
 
 func TestCheckDupJSONKeys(t *testing.T) {

cmd/globals.go

@@ -66,9 +66,15 @@ var (
 	globalIsBrowserEnabled = true
 	// This flag is set to 'true' when MINIO_BROWSER env is set.
 	globalIsEnvBrowser = false
+
 	// Set to true if credentials were passed from env, default is false.
 	globalIsEnvCreds = false
 
+	// This flag is set to 'true' wen MINIO_REGION env is set.
+	globalIsEnvRegion = false
+	// This flag is set to 'us-east-1' by default
+	globalServerRegion = globalMinioDefaultRegion
+
 	// Maximum size of internal objects parts
 	globalPutPartSize = int64(64 * 1024 * 1024)
 

cmd/server-main.go

@@ -454,6 +454,13 @@ func serverHandleEnvVars() {
 		globalIsEnvBrowser = true
 		globalIsBrowserEnabled = bool(browserFlag)
 	}
+
+	if serverRegion := os.Getenv("MINIO_REGION"); serverRegion != "" {
+		// region Envs are set globally.
+		globalIsEnvRegion = true
+		globalServerRegion = serverRegion
+	}
+
 }
 
 // serverMain handler called for 'minio server' command.

cmd/test-utils_test.go

@@ -490,6 +490,8 @@ func resetGlobalIsXL() {
 
 func resetGlobalIsEnvs() {
 	globalIsEnvCreds = false
+	globalIsEnvBrowser = false
+	globalIsEnvRegion = false
 }
 
 // Resets all the globals used modified in tests.