How to Send Notifications to Slack Using Python

📢 How to Send Notifications to Slack Using Python

🚀 Introduction

If you need to send automated notifications to Slack from different services, you can use Python and Slack Incoming Webhooks to achieve this. This guide provides a generic Python script that can be used for various use cases, such as:

• ✅ Sending notifications from AWS Lambda.
• ✅ Integrating with message queues like AWS SQS.
• ✅ Triggering alerts from any Python application.

🔧 Step 1: Create a Slack Channel

1️⃣ Open Slack and navigate to your workspace.

2️⃣ Click on the “+” (Add a Channel) button in the sidebar.

3️⃣ Select “Create a New Channel” from the options.

4️⃣ Enter a name for your channel (e.g., #aws-notifications).

5️⃣ Choose whether the channel should be public (accessible by all workspace members) or private (invite-only).

6️⃣ Click Create to finalize the channel setup and invite relevant team members if needed.

🔧 Step 2: Create and Configure a Slack App

1️⃣ Go to Slack API Console

• Open Slack API Console.

2️⃣ Click "Create an App"

• Choose "From scratch".
• Name it (e.g., aws-notifications).
• Choose a Slack workspace.

3️⃣ Enable Incoming Webhooks

• Inside your app's settings, navigate to "Incoming Webhooks".
• Toggle the switch to Activate Incoming Webhooks.
• Click "Add New Webhook to Workspace".
• Select the newly created Slack channel (e.g., #aws-notifications).
• Click Create App.

4️⃣ Generate a Webhook URL

• Click "Add New Webhook to Workspace".
• Select the #aws-notifications channel.
• Click "Allow" to grant the necessary permissions.
• Copy the generated Webhook URL. Example:

   https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX

📌 You'll use this Webhook URL in your Python script to send messages to Slack.

🔧 Step 3: Write the Python Script

This Python script sends messages to Slack. It works in AWS Lambda, local applications, or any automation tool.

import json
import urllib.request
import os

def send_slack_notification(message):
    slack_webhook_url = os.getenv("SLACK_WEBHOOK_URL")
    if not slack_webhook_url:
        raise ValueError("SLACK_WEBHOOK_URL environment variable is missing")

    data = json.dumps({"text": message}).encode("utf-8")
    req = urllib.request.Request(slack_webhook_url, data=data, headers={"Content-Type": "application/json"})

    try:
        with urllib.request.urlopen(req) as response:
            print("✅ Slack notification sent successfully!")
            return response.status
    except Exception as e:
        print(f"Failed to send message to Slack: {e}")
        return None

if __name__ == "__main__":
    message = "Hello from aws-notifications! 🚀"
    send_slack_notification(message)

🎯 Use Cases

✅ AWS Lambda Integration

Modify the script to accept event data in Lambda:

def lambda_handler(event, context):
    for record in event.get("Records", []):
        message_body = record.get("body", "No message body")
        send_slack_notification(f"AWS Lambda received: {message_body}")
    return {"status": "success"}

✅ Sending Slack Notifications from AWS SQS

AWS Lambda can trigger the script when an SQS message arrives.

✅ Sending Alerts from a Python Script

Use the script in any Python application to notify Slack:

send_slack_notification("AWS Lambda received: AWS Event Triggered")

🔧 Step 4: Sample Execution

✅ Running Locally

If running on your local machine, export your Slack webhook URL and execute the script:

export SLACK_WEBHOOK_URL=https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX
python script.py

Expected Output:

✅ Slack notification sent successfully!

✅ Running in AWS Lambda

Deploy the function and invoke it via AWS CLI:

aws lambda invoke \
  --function-name aws-notifications-lambda \
  --payload '{"Records": [{"body": "AWS Event Triggered"}]}' \
  response.json

Expected Slack Message:

AWS Lambda received: AWS Event Triggered

✅ Running via AWS SQS

Send a test message to SQS:

aws sqs send-message \
  --queue-url https://sqs.YOUR-REGION.amazonaws.com/YOUR-ACCOUNT-ID/YOUR-QUEUE \
  --message-body '{"event": "EC2 tag modified"}'

Slack will receive:

AWS Lambda received: EC2 tag modified

✅ Conclusion

Now, you have a generic Python script to send messages to Slack! 🎉 You’ve learned:

• How to create a Slack channel.
• How to configure Slack Webhooks.
• How to send messages using Python.
• How to integrate it into AWS Lambda, SQS, or any Python application.
• How to execute and test the script locally and in AWS.

💬 What other Slack integrations do you want to see? Let me know in the comments! 🚀