AWS Lambda: Send Notifications to your Discord Server using SNS Topics

Introduction

First, I'd like to thank @josuebustos for his article, which gave me the idea to come up with an alternative version.
You can integrate Lambda and SNS to send notifications regarding your resources, this brings a lot of possibilities, and we'll see a basic one. Such notifications will contain information from an SNS Topic in AWS. We'll learn how to send messages to a discord channel using webhooks.

Want to know more about Lambda?
Click here

Want to know more about Discord Webhook?
Click here

Getting Started

This tutorial is focused on being as simple as possible, so you can easily set up your lambda function within minutes and change it accordingly if you are having problems or only want the code here is the link of my repo with everything you'll need.

Prerequisites:

• AWS Account
• Discord Server

Create a Discord Server and a Webhook

The first step is to create a server. If you already have one skip until the webhook section.

In your Discord Dashboard.

1. Click the green button in the lower left corner to create a server.
   

2. Select one of the following options. I recommend you choose the 'Create my Own' option.
   

3. Select Select one of the following options. I recommend you choose the 'For me and my friends' option.
   

4. Customize your server with a name and an image if you want it.
   

5. I'll recommend you create a separate channel for the webhook to keep things organized. Click on the create channel button above the channel names.
   

6. Configure the channel as you like, but keep the Text option.
   

Time to set up the webhook

1. Click on the 'Gear' option on the name of the channel you want to edit.
   

2. Select the Integrations option to access the webhooks menu.
   Then press the Create webhook button
   

3. You can configure the name and the icon for your webhook. Select the channel you want your webhook to use.
   

4. Copy the webhook URL and save it somewhere because we'll use it in a few sections.
   

Create an SNS Topic

If you already have an SNS Topic that you want to use to send information to your discord channel, skip this section.

We will create a simple one, and then you can connect this topic to any other resource.

Let's get into the SNS service, selecting Simple Notification Service.

Select the topic option on the sidebar, and then the Create topic option.

Use the following options for a simple SNS topic and press on the create topic button

Now, it's time to subscribe to the SNS topic.
After the creation, this screen will pop up. If not, select your recently created topic in the topics section.
Press on the Create subscription option.

Select the following options to create a simple Email subscription, change the email field with the email you want to receive the notifications and press the Create subscription button.

You'll receive an email asking you to confirm the subscription, do it and then continue.

Now you have an SNS topic you can link to any other AWS resource, here is an example to use SNS topics and Codecommit triggers.

Prepare a Zip for AWS Lambda Layers

To utilize python packages in our lambda function, we need to upload a zip file with the content of our packages to Lambda Layers, follow the steps to create your zip or use mine and skip the creation.
You can follow most of the steps from a terminal or using the GUI.
Create a directory named python. The name is vital if you want to avoid possible issues.
You can use this instruction or create the folder manually.

$ mkdir python

For the following steps, you'll need a terminal, don't worry it's easy, and remember, if you are not so sure about this, download my zip here. Open a terminal inside your recently created directory or cd into it.

$ cd /d/Documents/python

Use this instruction to install the necessary packages inside the folder. In this case, we'll be installing discord-webhook.

$ pip3 install -t . discord-webhook

1. The next step is eliminating unnecessary files using this command.

$ rm -r *dist-info __pycache__

Don't worry if you get a warning after this command, proceed
without a problem.

1. Now, it's time to zip the folder. You can use this command or do it manually.

$ zip -r layer.zip python

Upload Zip to Lambda Layer

First, let's get into the lambda service

Select the Layer option on the sidebar and select Create Layer

Upload the zip and fill in the options following the image below.

Create the Lambda function

Now it's time to create the function. We will select the Function option on the same service, and then the Create function button.

This is an essential step. To make things easier, instead of selecting the author from scratch option, we will choose the Use a blueprint option. Then we will search for the sns blueprint for python and select it. Then press on the Configure button

Select the following options. Choose a name for your function.

Select your topic from the SNS topic list, and then press Create function

Import the Layer

Inside your function, press the layers button.

Then press Add a Layer

In this menu, we'll fill in the options like the image below.
Under the custom layer option, select the Layer we just created and press Add

Code for the Function

Now you can replace the code from the function with the following:

from discord_webhook import DiscordWebhook, DiscordEmbed
import json

print('Loading function')


def lambda_handler(event, context):
    message = event['Records'][0]['Sns']['Message']
    print("From SNS: " + message)

    webhook = DiscordWebhook(url="replace with your webhook url")
    embed = DiscordEmbed(
        title="AWS",
        description=message,
        color="00ff00")

    #Select an image if you want
    #embed.set_image(url="")

    webhook.add_embed(embed)
    webhook.execute()

    return message

Depending on your SNS topic, you may want to filter the messages with a simple sentence. If that's the case, use the following:

from discord_webhook import DiscordWebhook, DiscordEmbed
import json

print('Loading function')


def lambda_handler(event, context):
    #print("Received event: " + json.dumps(event, indent=2))
    message = event['Records'][0]['Sns']['Message']
    print("From SNS: " + message)
    message_str=str(message)
    ###If sentence to filter the messages you want to receive.
    if "New" in message:
        webhook = DiscordWebhook(url="replace with your webhook url")
        embed = DiscordEmbed(
            title="AWS",
            description=message,
            color="00ff00")

        #embed.set_image(url="")
        webhook.add_embed(embed)
        webhook.execute()
    else:
        pass
    return message

Configure Test Event

Before the testing, we need to configure a Test Event.
Press on the test option and then on the Configure test event option.

Choose a name for your test event. A template for the test event would be already selected. If not, search for the Sns notification template.

Press Save at the end.

Test the code

Before testing, press the deploy button.

Now you're all set. Press on the Test button and check your discord channel.

And here is what it looks like when triggered by an SNS message.

If you are having problems related to the module while testing, please refer to the official documentation here Or try using the python.zip that is in my repo.

Conclusion

Now you know how to set up a discord notifier that listens to an SNS Topic using Lambdas.
I hope you found this helpful.

Keep Learning.

Comments

[Josue Bustos]

Great tutorial Said! ⭐

And thanks for the mention! 😉

[Said Silva]

Thanks to you Josue! 👏

Greetings.