Added an example for sending push notification to FCM endpoint using …

gov2/sns/publish_to_fcm_endpoint.go

@@ -0,0 +1,89 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+
+	"github.com/aws/aws-sdk-go-v2/aws"
+	"github.com/aws/aws-sdk-go-v2/config"
+	"github.com/aws/aws-sdk-go-v2/service/sns"
+)
+
+// This code example shows you how to send a push notification to a Firebase Cloud Messaging (FCM) endpoint
+// using AWS SNS SDK.
+
+func main() {
+	ctx := context.Background()
+
+	sdkConfig, err := config.LoadDefaultConfig(ctx)
+	if err != nil {
+		fmt.Println("Couldn't load default configuration. Have you set up your AWS account?")
+		fmt.Println(err)
+		return
+	}
+
+	snsClient := sns.NewFromConfig(sdkConfig)
+
+	notificationData := map[string]interface{}{
+		"notification": map[string]string{
+			"title": "Notification Title",
+			"body":  "Sample Body",
+		},
+		"data": map[string]string{
+			"sampleData1": "Sample Data",
+			"sampleData2": "Sample Data",
+		},
+	}
+
+	// We need to Marshal this data into JSON format, then put it as a
+	// value to GCM key inside another map, and then marshal that
+	// map to get the required format to be sent to SNS.
+
+	notificationDataJSON, err := json.Marshal(notificationData)
+
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	message := map[string]interface{}{
+		"default": "Default Value",
+		"GCM": string(notificationDataJSON),
+	}
+
+	messageJSON, err := json.Marshal(message)
+
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	endpointArn := "user-endpoint-arn"
+
+	_, err = snsClient.Publish(ctx, &sns.PublishInput{
+		TargetArn:        &endpointArn,
+		MessageStructure: aws.String("json"),
+		Message:          aws.String(string(messageJSON)),
+	})
+
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	// or if you want to pass the message data directly as a string to avoid the double
+	// JSON marshalling, you can do that by passing it in the following format:
+	//
+	// Message: aws.String(
+	// "{\"default\":\"Default Value\","+
+	//   "\"GCM\":\"{\\\"notification\\\":{" +
+	// 		"\\\"body\\\":\\\"Body\\\"," +
+	// 		"\\\"title\\\":\\\"Title\\\"" +
+	// 		"}," +
+	// 		"\\\"data\\\":{" +
+	// 		"\\\"sampleData1\\\":\\\"Sample Data\\\"," +
+	// 		"\\\"sampleData2\\\":\\\"Sample Data\\\"" +
+	// 		"}}\"}"
+	// ),
+}