k8s: support enable/disable mining

k8s/blockchain_example.go

@@ -28,7 +28,7 @@ func ExampleK8SBlockchain() {
 		ImageRepository("quay.io/amis/geth"),
 		ImageTag("istanbul_develop"),
 		ServiceType("LoadBalancer"),
-		Mine(),
+		Mine(true),
 	)
 	defer chain.Finalize()
 

k8s/ethereum.go

@@ -346,11 +346,23 @@ func (eth *ethereum) AddPeer(address string) error {
 }
 
 func (eth *ethereum) StartMining() error {
-	return nil
+	client := eth.NewClient()
+	if client == nil {
+		return errors.New("failed to retrieve client")
+	}
+	defer client.Close()
+
+	return client.StartMining(context.Background())
 }
 
 func (eth *ethereum) StopMining() error {
-	return nil
+	client := eth.NewClient()
+	if client == nil {
+		return errors.New("failed to retrieve client")
+	}
+	defer client.Close()
+
+	return client.StopMining(context.Background())
 }
 
 func (eth *ethereum) Accounts() (addrs []common.Address) {

k8s/option.go

@@ -62,9 +62,9 @@ func NetworkID(networkID string) Option {
 	}
 }
 
-func Mine() Option {
+func Mine(mine bool) Option {
 	return func(eth *ethereum) {
-		eth.args = append(eth.args, "ethereum.mining.enabled=true")
+		eth.args = append(eth.args, fmt.Sprintf("ethereum.mining.enabled=%v", mine))
 	}
 }