[improve][doc] add golang transaction demo in txn-use.md

docs/txn-use.md

@@ -54,7 +54,7 @@ To use Pulsar transaction API, complete the following steps.
     Transaction coordinator metadata setup success
     ```
 
-3. Create a Pulsar client and enable transactions.
+3. Create a Pulsar client and enable transactions. Since client need to know transaction coordinator from system topic, please make sure your client role has system namespace `pulsar/system` produce/consume permissions.
 
 4. Create producers and consumers.
 
@@ -80,6 +80,13 @@ To use Pulsar transaction API, complete the following steps.
 
     **Input**
 
+````mdx-code-block
+<Tabs groupId="api-choice"
+  defaultValue="Java"
+  values={[{"label":"Java","value":"Java"},{"label":"Go","value":"Go"}]}>
+
+<TabItem value="Java">
+
     ```java
     PulsarClient client = PulsarClient.builder()
                     // Step 3: create a Pulsar client and enable transactions.
@@ -162,6 +169,128 @@ To use Pulsar transaction API, complete the following steps.
     }
     ```
 
+</TabItem>
+<TabItem value="Go">
+
+  ```go
+	// Step 3: create a Pulsar client and enable transactions.
+	client, err := pulsar.NewClient(pulsar.ClientOptions{
+		URL:               "<serviceUrl>",
+		EnableTransaction: true,
+	})
+	if err != nil {
+		log.Fatalf("create client fail, err = %v", err)
+	}
+	defer client.Close()
+	// Step 4: create three producers to produce messages to input and output topics.
+	inputTopic := "inputTopic"
+	outputTopicOne := "outputTopicOne"
+	outputTopicTwo := "outputTopicTwo"
+	subscriptionName := "your-subscription-name"
+	inputProducer, _ := client.CreateProducer(pulsar.ProducerOptions{
+		Topic:       inputTopic,
+		SendTimeout: 0,
+	})
+	defer inputProducer.Close()
+	outputProducerOne, _ := client.CreateProducer(pulsar.ProducerOptions{
+		Topic:       outputTopicOne,
+		SendTimeout: 0,
+	})
+	defer outputProducerOne.Close()
+	outputProducerTwo, _ := client.CreateProducer(pulsar.ProducerOptions{
+		Topic:       outputTopicTwo,
+		SendTimeout: 0,
+	})
+	defer outputProducerTwo.Close()
+
+	// Step 4: create three consumers to consume messages from input and output topics.
+	inputConsumer, _ := client.Subscribe(pulsar.ConsumerOptions{
+		Topic:            inputTopic,
+		SubscriptionName: subscriptionName,
+	})
+	defer inputConsumer.Close()
+	outputConsumerOne, _ := client.Subscribe(pulsar.ConsumerOptions{
+		Topic:            outputTopicOne,
+		SubscriptionName: subscriptionName,
+	})
+	defer outputConsumerOne.Close()
+	outputConsumerTwo, _ := client.Subscribe(pulsar.ConsumerOptions{
+		Topic:            outputTopicTwo,
+		SubscriptionName: subscriptionName,
+	})
+	defer outputConsumerTwo.Close()
+
+	// Step 5: produce messages to input topics.
+	ctx := context.Background()
+	count := 2
+	for i := 0; i < count; i++ {
+		inputProducer.Send(ctx, &pulsar.ProducerMessage{
+			Payload: []byte(fmt.Sprintf("Hello Pulsar! count : %d", i)),
+		})
+	}
+	// Step 5: consume messages and produce them to output topics with transactions.
+	for i := 0; i < count; i++ {
+		// Step 5: the consumer successfully receives messages.
+		message, err := inputConsumer.Receive(ctx)
+		if err != nil {
+			log.Printf("receive message from %s fail, err = %v", inputTopic, err)
+			continue
+		}
+		// Step 6: create transactions.
+		// The transaction timeout is specified as 10 seconds.
+		// If the transaction is not committed within 10 seconds, the transaction is automatically aborted.
+		txn, err := client.NewTransaction(10 * time.Second)
+		if err != nil {
+			log.Printf("create txn fail, err = %v", err)
+			continue
+		}
+		// Step 6: you can process the received message with your use case and business logic.
+		// processMessage(message)
+		// Step 7: the producers produce messages to output topics with transactions
+		_, err = outputProducerOne.Send(context.Background(), &pulsar.ProducerMessage{
+			Transaction: txn,
+			Payload:     []byte(fmt.Sprintf("Hello Pulsar! outputTopicOne count : %d", i)),
+		})
+		if err != nil {
+			log.Printf("send to producerOne fail %v", err)
+			txn.Abort(ctx)
+		}
+		_, err = outputProducerTwo.Send(context.Background(), &pulsar.ProducerMessage{
+			Transaction: txn,
+			Payload:     []byte(fmt.Sprintf("Hello Pulsar! outputTopicTwo count : %d", i)),
+		})
+		if err != nil {
+			log.Printf("send to producerTwo fail %v", err)
+			txn.Abort(ctx)
+		}
+		// Step 7: the consumers acknowledge the input message with the transactions *individually*.
+		err = inputConsumer.AckWithTxn(message, txn)
+		if err != nil {
+			log.Printf("ack message fail %v", err)
+			txn.Abort(ctx)
+		}
+		// Step 8: commit transactions.
+		err = txn.Commit(ctx)
+		if err != nil {
+			log.Printf("commit txn fail %v", err)
+		}
+	}
+
+	// Final result: consume messages from output topics and print them.
+	for i := 0; i < count; i++ {
+		message, _ := outputConsumerOne.Receive(ctx)
+		log.Printf("Receive transaction message: %s", string(message.Payload()))
+	}
+	for i := 0; i < count; i++ {
+		message, _ := outputConsumerTwo.Receive(ctx)
+		log.Printf("Receive transaction message: %s", string(message.Payload()))
+	}
+  ```
+
+</TabItem>
+</Tabs>
+````
+
     **Output**
 
     ```java

versioned_docs/version-3.0.x/txn-use.md

@@ -49,7 +49,7 @@ Currently, [Pulsar transaction API](/api/admin/) is available in **Pulsar 2.8.0
     Transaction coordinator metadata setup success
     ```
 
-3. Create a Pulsar client and enable transactions.
+3. Create a Pulsar client and enable transactions. Since client need to know transaction coordinator from system topic, please make sure your client role has system namespace `pulsar/system` produce/consume permissions.
 
 4. Create producers and consumers.
 
@@ -75,6 +75,13 @@ Currently, [Pulsar transaction API](/api/admin/) is available in **Pulsar 2.8.0
 
     **Input**
 
+````mdx-code-block
+<Tabs groupId="api-choice"
+  defaultValue="Java"
+  values={[{"label":"Java","value":"Java"},{"label":"Go","value":"Go"}]}>
+
+<TabItem value="Java">
+
     ```java
     PulsarClient client = PulsarClient.builder()
                     // Step 3: create a Pulsar client and enable transactions.
@@ -157,6 +164,128 @@ Currently, [Pulsar transaction API](/api/admin/) is available in **Pulsar 2.8.0
     }
     ```
 
+</TabItem>
+<TabItem value="Go">
+
+  ```go
+  // Step 3: create a Pulsar client and enable transactions.
+	client, err := pulsar.NewClient(pulsar.ClientOptions{
+		URL:               "<serviceUrl>",
+		EnableTransaction: true,
+	})
+	if err != nil {
+		log.Fatalf("create client fail, err = %v", err)
+	}
+	defer client.Close()
+	// Step 4: create three producers to produce messages to input and output topics.
+	inputTopic := "inputTopic"
+	outputTopicOne := "outputTopicOne"
+	outputTopicTwo := "outputTopicTwo"
+	subscriptionName := "your-subscription-name"
+	inputProducer, _ := client.CreateProducer(pulsar.ProducerOptions{
+		Topic:       inputTopic,
+		SendTimeout: 0,
+	})
+	defer inputProducer.Close()
+	outputProducerOne, _ := client.CreateProducer(pulsar.ProducerOptions{
+		Topic:       outputTopicOne,
+		SendTimeout: 0,
+	})
+	defer outputProducerOne.Close()
+	outputProducerTwo, _ := client.CreateProducer(pulsar.ProducerOptions{
+		Topic:       outputTopicTwo,
+		SendTimeout: 0,
+	})
+	defer outputProducerTwo.Close()
+
+	// Step 4: create three consumers to consume messages from input and output topics.
+	inputConsumer, _ := client.Subscribe(pulsar.ConsumerOptions{
+		Topic:            inputTopic,
+		SubscriptionName: subscriptionName,
+	})
+	defer inputConsumer.Close()
+	outputConsumerOne, _ := client.Subscribe(pulsar.ConsumerOptions{
+		Topic:            outputTopicOne,
+		SubscriptionName: subscriptionName,
+	})
+	defer outputConsumerOne.Close()
+	outputConsumerTwo, _ := client.Subscribe(pulsar.ConsumerOptions{
+		Topic:            outputTopicTwo,
+		SubscriptionName: subscriptionName,
+	})
+	defer outputConsumerTwo.Close()
+
+	// Step 5: produce messages to input topics.
+	ctx := context.Background()
+	count := 2
+	for i := 0; i < count; i++ {
+		inputProducer.Send(ctx, &pulsar.ProducerMessage{
+			Payload: []byte(fmt.Sprintf("Hello Pulsar! count : %d", i)),
+		})
+	}
+	// Step 5: consume messages and produce them to output topics with transactions.
+	for i := 0; i < count; i++ {
+		// Step 5: the consumer successfully receives messages.
+		message, err := inputConsumer.Receive(ctx)
+		if err != nil {
+			log.Printf("receive message from %s fail, err = %v", inputTopic, err)
+			continue
+		}
+		// Step 6: create transactions.
+		// The transaction timeout is specified as 10 seconds.
+		// If the transaction is not committed within 10 seconds, the transaction is automatically aborted.
+		txn, err := client.NewTransaction(10 * time.Second)
+		if err != nil {
+			log.Printf("create txn fail, err = %v", err)
+			continue
+		}
+		// Step 6: you can process the received message with your use case and business logic.
+		// processMessage(message)
+		// Step 7: the producers produce messages to output topics with transactions
+		_, err = outputProducerOne.Send(context.Background(), &pulsar.ProducerMessage{
+			Transaction: txn,
+			Payload:     []byte(fmt.Sprintf("Hello Pulsar! outputTopicOne count : %d", i)),
+		})
+		if err != nil {
+			log.Printf("send to producerOne fail %v", err)
+			txn.Abort(ctx)
+		}
+		_, err = outputProducerTwo.Send(context.Background(), &pulsar.ProducerMessage{
+			Transaction: txn,
+			Payload:     []byte(fmt.Sprintf("Hello Pulsar! outputTopicTwo count : %d", i)),
+		})
+		if err != nil {
+			log.Printf("send to producerTwo fail %v", err)
+			txn.Abort(ctx)
+		}
+		// Step 7: the consumers acknowledge the input message with the transactions *individually*.
+		err = inputConsumer.AckWithTxn(message, txn)
+		if err != nil {
+			log.Printf("ack message fail %v", err)
+			txn.Abort(ctx)
+		}
+		// Step 8: commit transactions.
+		err = txn.Commit(ctx)
+		if err != nil {
+			log.Printf("commit txn fail %v", err)
+		}
+	}
+
+	// Final result: consume messages from output topics and print them.
+	for i := 0; i < count; i++ {
+		message, _ := outputConsumerOne.Receive(ctx)
+		log.Printf("Receive transaction message: %s", string(message.Payload()))
+	}
+	for i := 0; i < count; i++ {
+		message, _ := outputConsumerTwo.Receive(ctx)
+		log.Printf("Receive transaction message: %s", string(message.Payload()))
+	}
+  ```
+
+</TabItem>
+</Tabs>
+````
+
     **Output**
 
     ```java