Serverless Github webhook listener

This service will listen to github webhooks fired by a given repository.

Use Cases

  • Custom github notifications
  • Automatically tagging github issues
  • Pinging slack on new Pull requests
  • Welcoming new stargazers
  • etc.

How it works

┌───────────────┐               ┌───────────┐
│               │               │           │
│  Github repo  │               │   Github  │
│   activity    │────Trigger───▶│  Webhook  │
│               │               │           │
└───────────────┘               └───────────┘
                                      │
                     ┌────POST────────┘
                     │
          ┌──────────▼─────────┐
          │ ┌────────────────┐ │
          │ │  API Gateway   │ │
          │ │    Endpoint    │ │
          │ └────────────────┘ │
          └─────────┬──────────┘
                    │
                    │
         ┌──────────▼──────────┐
         │ ┌────────────────┐  │
         │ │                │  │
         │ │     Lambda     │  │
         │ │    Function    │  │
         │ │                │  │
         │ └────────────────┘  │
         └─────────────────────┘
                    │
                    │
                    ▼
         ┌────────────────────┐
         │                    │
         │      Do stuff      │
         │                    │
         └────────────────────┘

Setup

  1. Set your webhook secret token in serverless.yml by replacing REPLACE-WITH-YOUR-SECRET-HERE in the environment variables GITHUB_WEBHOOK_SECRET.
provider:
  name: aws
  runtime: nodejs12.x
  environment:
    GITHUB_WEBHOOK_SECRET: REPLACE-WITH-YOUR-SECRET-HERE
  1. Deploy the service
serverless deploy

After the deploy has finished you should see something like:

Service Information
service: github-webhook-listener
stage: dev
region: us-east-1
api keys:
  None
endpoints:
  POST - https://abcdefg.execute-api.us-east-1.amazonaws.com/dev/webhook
functions:
  github-webhook-.....github-webhook-listener-dev-githubWebhookListener
  1. Configure your webhook in your github repository settings. Setting up a Webhook

(1.) Plugin your API POST endpoint. (https://abcdefg.execute-api.us-east-1.amazonaws.com/dev/webhook in this example). Run sls info to grab your endpoint if you don't have it handy.

(2.) Plugin your secret from GITHUB_WEBHOOK_SECRET environment variable

(3.) Choose the types of events you want the github webhook to fire on

webhook-steps

  1. Manually trigger/test the webhook from settings or do something in your github repo to trigger a webhook.

You can tail the logs of the lambda function with the below command to see it running.

serverless logs -f githubWebhookListener -t

You should see the event from github in the lambda functions logs.

  1. Use your imagination and do whatever you want with your new github webhook listener! 🎉

Let us know if you come up with a cool use case for this service =)