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Using Go, Python or Node.js with SNS

Reviewed on 09 April 2024 • Published on 04 January 2023

AWS provides a number of Software Development Kits (SDKs) which provide language-specific APIs for AWS services, including SNS.

AWS provides a dedicated SDK for Go.
The AWS SDK for Python is Boto3.
For Node.js, use the AWS SDK for JavaScript, which can be installed from NPM.

This page provides code samples to show you how to get started using these SDKs with Scaleway Messaging and Queuing SNS.

Before you start

To complete the actions presented below, you must have:

A Scaleway account logged into the console
Owner status or IAM permissions allowing you to perform actions in the intended Organization
Activated SNS
Valid credentials for SNS
Installed the relevant AWS SDK for Go, Python and/or JavaScript

Go

The following code shows you how to connect to SNS:

import (
  "github.com/aws/aws-sdk-go/aws"
  "github.com/aws/aws-sdk-go/aws/credentials"
  "github.com/aws/aws-sdk-go/aws/session"
  "github.com/aws/aws-sdk-go/service/sns"
)
func main() {
  awsSession := session.Must(session.NewSession(&aws.Config{
    Region:   aws.String("fr-par"),
    Endpoint: aws.String("http://sns.mnq.fr-par.scaleway.com"),
    Credentials: credentials.NewStaticCredentials(AwsAccessKey, AwsSecretKey, ""),
  }))
  awsSns := sns.New(awsSession)
  [...]
}

Note

The Endpoint for Scaleway Messaging and Queuing with SNS is https://sns.mnq.fr-par.scaleway.com. The values for the access and secret keys should be the credentials you generated for SNS.

Once connected to the SNS service, you can use any of the SDK’s available functions. Be aware though that some functions are not supported by Scaleway Messaging and Queuing, so make sure to check the link for more details on these. See the official SDK documentation for more information on getting started with the SDK, or keep reading for some code examples.

Create topic (Go)

createTopicResponse, _ := awsSNS.CreateTopic(&sns.CreateTopicInput{
  Name: aws.String("my-test-topic"),
})
fmt.Println(*createTopicResponse.TopicArn)

Publish messages to this topic (Go)

Be careful: messages sent to topics with no subscriptions are automatically deleted

for i := 0; i < 10; i++ {
  _, _ = awsSNS.Publish(&sns.PublishInput{
    Message:  aws.String(fmt.Sprintf("Hello World: %d", i)),
    TopicArn: createTopicResponse.TopicArn,
  })
}

Create subscriptions to this topic (Go)

Subscribe to an SQS queue from the same Scaleway Project

This is no longer supported. Watch this space for future developments.

Subscribe to a public Scaleway function

This code triggers the function each time a message is published to the topic.

You can find the value for [Function URL] in the Scaleway console in the Endpoints tab of your function’s Overview page.

_, _ = awsSns.Subscribe(&sns.SubscribeInput{
  Endpoint: aws.String(FunctionUrl),
  Protocol: aws.String("lambda"),
  TopicArn: createTopicResponse.TopicArn,
})
Setting up an SQS queue from the same Scaleway Project (as a Dead Letter Queue), is no longer supported. Watch this space for future developments.
#### Subscribe to an HTTP/S endpoint
```go
_, _ = awsSns.Subscribe(&sns.SubscribeInput{
  Endpoint: aws.String(Url),
  Protocol: aws.String("http"), // or https
  TopicArn: createTopicResponse.TopicArn,
})

The HTTP server should receive an HTTP request with a body in json matching the following format:

{
"Type": "SubscriptionConfirmation",
"Token": "<REDACTED-CONFIRMATION-TOKEN>",
"MessageId": "<REDACTED-MESSAGE-ID>",
"TopicArn": "arn:scw:sns:fr-par:<REDACTED-ID>:MyTopic",
"Message": "You have chosen to subscribe to the topic arn:scw:sns:fr-par:<REDACTED-ID>:MyTopic.\nTo confirm the subscription, visit the SubscribeURL included in this message.",
"Timestamp": "2022-06-29T10:03:34Z",
"SignatureVersion": "1",
"Signature": "<REDACTED-SIGNATURE>",
"SigningCertURL": "https://messaging.s3.fr-par.scw.cloud/fr-par/sns/sns_certificate_[certSerialNumber].crt",
"SubscribeURL": "<THE-CONFIRMATION-LINK>" // Get the confirmation link located here
}

The signing certificate of the message is in the JSON of the SigningCertURL. This certificate is also signed by the trust chain certificate (common name sns.mnq.srr.scw.cloud). For more information about verifying the authenticity of the message, refer to the official AWS documentation.

To confirm the subscription, make a request to the SubscribeURL using your browser or curl.

Delete all subscriptions (Go)

listSubscriptions, _ := awsSns.ListSubscriptionsByTopic(&sns.ListSubscriptionsByTopicInput{
  TopicArn: createTopicResponse.TopicArn,
})
for _, sub := range listSubscriptions.Subscriptions {
  awsSns.Unsubscribe(&sns.UnsubscribeInput{
    SubscriptionArn: sub.SubscriptionArn,
  })
}

Python

The following code shows you how to connect to SNS using Boto3’s resource(). You could also use client(), but we favor resource() as it is more pythonesque:

sns = boto3.resource('sns',
  endpoint_url=[],
  aws_access_key_id=[],
  aws_secret_access_key=[],
  region_name='fr-par')

Note

The endpoint_url for Scaleway Messaging and Queuing with SNS is https://sns.mnq.fr-par.scaleway.com. The values for the access and secret keys should be the credentials you generated for SNS.

Once connected to the SNS service, you can use any of the SDK’s available functions. However, some functions are not supported by Scaleway Messaging and Queuing, so do check the link to make sure. See the official SDK documentation for more information, or keep reading for some code examples.

Create topic (Python)

# Create a topic. This returns an SNS.Topic instance
topic = sns.create_topic(Name='test')  # You can now access identifiers and attributes
print(topic.arn)
print(topic.attributes)

Publish messages to this topic (Python)

Be careful: messages sent to topics with no subscriptions are automatically deleted

for i in range (0,10):
  topic.publish(Message="Hello World: "+str(i))

Create subscriptions to this topic (Python)

Subscribe to an SQS queue from the same Scaleway Project

This is no longer supported. Watch this space for future developments.

Subscribe to a public Scaleway function

This code triggers the function each time a message is published to the topic.

You can find the value for [Function URL] in the Scaleway console in the Endpoints tab of your function’s Overview page.

subscription_functions = topic.subscribe(
    Protocol='lambda',
    Endpoint=[Function URL],
    ReturnSubscriptionArn=True
)

Setting up an SQS queue from the same Scaleway Project (as a Dead Letter Queue), is no longer supported. Watch this space for future developments.

subscription_functions = topic.subscribe(
    Protocol='lambda',
    Endpoint=[Function URL],
    ReturnSubscriptionArn=True,
    Attributes={
      'RedrivePolicy': '{"deadLetterTargetArn": "[Queue ARN]"}'
    }
)

Subscribe to an HTTP/S endpoint

subscription = topic.subscribe(
    Protocol='http', //or https
    Endpoint=url,
    ReturnSubscriptionArn=True
)

The HTTP server should receive an HTTP request with a body in json matching the following format:

{
"Type": "SubscriptionConfirmation",
"Token": "<REDACTED-CONFIRMATION-TOKEN>",
"MessageId": "<REDACTED-MESSAGE-ID>",
"TopicArn": "arn:scw:sns:fr-par:<REDACTED-ID>:MyTopic",
"Message": "You have chosen to subscribe to the topic arn:scw:sns:fr-par:<REDACTED-ID>:MyTopic.\nTo confirm the subscription, visit the SubscribeURL included in this message.",
"Timestamp": "2022-06-29T10:03:34Z",
"SignatureVersion": "1",
"Signature": "<REDACTED-SIGNATURE>",
"SigningCertURL": "http://<REDACTED-URL>/SNStest.crt",
"SubscribeURL": "<THE-CONFIRMATION-LINK>" // Get the confirmation link located here
}

To confirm the subscription, make a request to the SubscribeURL using your browser or curl.

Delete all subscriptions (Python)

for subs in topic.subscriptions.all():
    subs.delete()

Node.js

The following code sample shows how to connect to SNS:

import { 
    CreateTopicCommand,
    DeleteTopicCommand,
    ListSubscriptionsByTopicCommand,
    ListTopicsCommand,
    PublishCommand,
    SNSClient,
    SubscribeCommand,
    UnsubscribeCommand,
 } from "@aws-sdk/client-sns";
var snsClient = new SNSClient({
    credentials : {
        accessKeyId : "",
        secretAccessKey: ""
    },
    region: "par",
    endpoint: "https://sns.mnq.fr-par.scaleway.com",
    
})

Note

The endpoint_url for Scaleway Messaging and Queuing with SNS is https://sns.mnq.fr-par.scaleway.com. For the access and secret key values, use the credentials you generated for SNS.

Create topic (NodeJS)

You can find all available parameters for createTopic in the AWS documentation.

var paramsTopic = {
    Name: 'MyTopic'
  };
const commandCreateTopic = new CreateTopicCommand(paramsTopic);
const restCreateTopic = await snsClient.send(commandCreateTopic);
const topicARN= restCreateTopic.TopicArn;
console.log(topicARN);

Publish messages to this topic (NodeJS)

Be careful: messages sent to topics with no subscriptions are automatically deleted.

This code sample demonstrates how to send a message with MessageAttributes. For more information on MessageAttributes, refer to the official documentation.

var paramsSend = {
    Message: 'MyMessage', 
    Subject: 'MySubject',
    TopicArn: topicARN,
  };
const commandPublishCommand = new PublishCommand(paramsSend);
const restPublishCommand = await snsClient.send(commandPublishCommand);
console.log(restPublishCommand.MessageId);

You can find all available parameters for the subscribe operation in the [AWS documentation] (https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/clients/client-sns/classes/subscribecommand.html)

Subscribe to an SQS queue from the same Scaleway Project

This is no longer supported. Watch this space for future developments.

Subscribe to a public Scaleway function

This code triggers the function each time a message is published to the topic.

You can find the value for [Function URL] in the Scaleway console in the Endpoints tab of your function’s Overview page.

var params = {
    Protocol: 'lambda', 
    TopicArn: topicARN, 
    Endpoint: 'YOUR FUNCTION ENDPOINT',
    ReturnSubscriptionArn: true 
  };
const command = new SubscribeCommand(params);
const rest = await snsClient.send(command);
console.log(rest.SubscriptionArn);

Setting up an SQS queue from the same Scaleway Project (as a Dead Letter Queue), is no longer supported. Watch this space for future developments.

Subscribe to an HTTP/S endpoint

var paramsHttpsSubscription = {
    Protocol: 'https', 
    TopicArn: topicARN, 
    Endpoint: 'YOUR SERVER ENDPOINT',
    ReturnSubscriptionArn: true 
  };
const commandHttpsSubscription = new SubscribeCommand(paramsHttpsSubscription);
const restHttpsSubscription = await snsClient.send(commandHttpsSubscription);
console.log(restHttpsSubscription.SubscriptionArn);

The HTTP server receives an HTTP request with a json body matching the following format:

{
"Type": "SubscriptionConfirmation",
"Token": "<REDACTED-CONFIRMATION-TOKEN>",
"MessageId": "<REDACTED-MESSAGE-ID>",
"TopicArn": "arn:scw:sns:fr-par:<REDACTED-ID>:MyTopic",
"Message": "You have chosen to subscribe to the topic arn:scw:sns:fr-par:<REDACTED-ID>:MyTopic.\nTo confirm the subscription, visit the SubscribeURL included in this message.",
"Timestamp": "2022-06-29T10:03:34Z",
"SignatureVersion": "1",
"Signature": "<REDACTED-SIGNATURE>",
"SigningCertURL": "http://<REDACTED-URL>/SNStest.crt",
"SubscribeURL": "<THE-CONFIRMATION-LINK>" // Get the confirmation link located here
}

To confirm the subscription, make a request to the SubscribeURL using your browser or curl.

Delete all subscriptions (NodeJS)

The following code sample deletes all subscriptions to a topic.

var paramsListSubs = {
    TopicArn: topicARN, 
  };
const commandListSubs = new ListSubscriptionsByTopicCommand(paramsListSubs);
const restListSubs = await snsClient.send(commandListSubs);
const subscriptionsList = restListSubs.Subscriptions;
subscriptionsList.forEach(async function (element) {
try {
    var params = {
        SubscriptionArn: element.SubscriptionArn 
      };
      const command = new UnsubscribeCommand(params)
      const rest = await snsClient.send(command)
      console.log("Unsubscribing : ",rest.$metadata.httpStatusCode)
} catch (e) {
  throw new Error(e.message)
}
});

Delete all topics (NodeJS)

The following code sample deletes all your SNS topics.

// First List Topics
const commandList = new ListTopicsCommand({});
const restTopicList = await snsClient.send(commandList);
const TopicList = restTopicList.Topics
// For Each Topic in the list, apply the Delete Topic Command
TopicList.forEach(async function (element) {
    try {
        var params = {
            TopicArn: element.TopicArn 
          };
          const command = new DeleteTopicCommand(params)
          const rest = await snsClient.send(command)
          console.log("Deleting : ",rest.$metadata.httpStatusCode)
    
    } catch (e) {
      throw new Error(e.message)
    }
    });