Make sure driver oper state can upgrade gracefully

Author: Joji Mekkatt

drivers/ovsdriver.go

@@ -151,6 +151,16 @@ func (d *OvsDriver) Init(info *core.InstanceInfo) error {
 		}
 	}
 
+	// make sure LocalEpInfo exists
+	if d.oper.LocalEpInfo == nil {
+		d.oper.LocalEpInfo = make(map[string]*EpInfo)
+		// write the oper
+		err = d.oper.Write()
+		if err != nil {
+			return err
+		}
+	}
+
 	log.Infof("Initializing ovsdriver")
 
 	// Init switch DB

drivers/ovsdriver_test.go

@@ -276,6 +276,48 @@ func TestOvsDriverDeinit(t *testing.T) {
 
 }
 
+func TestOvsDriverStateUpgrade(t *testing.T) {
+	driver := &OvsDriver{}
+	fMode := "bridge"
+	stateDriver := &state.FakeStateDriver{}
+	stateDriver.Init(nil)
+	instInfo := &core.InstanceInfo{HostLabel: testHostLabelStateful,
+		StateDriver: stateDriver, FwdMode: fMode}
+
+	operOvs := &OvsDriverOperState{CurrPortNum: testCurrPortNum}
+	operOvs.StateDriver = stateDriver
+	operOvs.ID = testHostLabelStateful
+	err := operOvs.Write()
+	if err != nil {
+		t.Fatalf("writing driver oper state failed. Error: %s", err)
+	}
+
+	err = driver.Init(instInfo)
+	if err != nil {
+		t.Fatalf("driver init failed. Error: %s", err)
+	}
+
+	if driver.oper.CurrPortNum != testCurrPortNum {
+		t.Fatalf("Unexpected driver oper state. Expected port num: %d, rcvd port number: %d",
+			testCurrPortNum, driver.oper.CurrPortNum)
+	}
+
+	// Try to save local endpoint info
+	driver.oper.localEpInfoMutex.Lock()
+	driver.oper.LocalEpInfo["testID"] = &EpInfo{
+		Ovsportname: "testVport",
+		EpgKey:      "testTen:testEpg",
+		BridgeType:  "vlan",
+	}
+	driver.oper.localEpInfoMutex.Unlock()
+	err = driver.oper.Write()
+	if err != nil {
+		t.Fatalf("driver opern write failed. Error: %s", err)
+	}
+
+	defer func() { driver.Deinit() }()
+}
+
 func TestOvsDriverCreateEndpoint(t *testing.T) {
 	driver := initOvsDriver(t)
 	defer func() { driver.Deinit() }()