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This guide walks you through using ngrok to receive Sonatype Nexus webhooks on your localhost app. By integrating ngrok with Sonatype Nexus, you can:
  • Develop and test Sonatype Nexus webhooks locally without deploying to a public environment or setting up HTTPS.
  • Inspect and troubleshoot requests from Sonatype Nexus in real time via the inspection UI and API.
  • Modify and replay Sonatype Nexus webhook requests with a single click instead of reproducing events manually in your Sonatype Nexus account.
  • Secure your app with Sonatype Nexus webhook validation provided by ngrok. Invalid requests are blocked by ngrok before reaching your app.

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What you’ll need

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1. Start your app

For this tutorial, you can use the sample Node.js app on GitHub. To install the sample, run the following in a terminal: 
git clone https://github.com/ngrok/ngrok-webhook-nodejs-sample.git
cd ngrok-webhook-nodejs-sample
npm install
Then start the app: 
npm start
The app runs on port 3000 by default. You can confirm it’s running by visiting http://localhost:3000. The app logs request headers and body in the terminal and shows a message in the browser.

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2. Expose your app with ngrok

Once your app is running locally, you’re ready to put it online securely using ngrok.
The ngrok agent uses your authtoken to authenticate when you start a tunnel.
  • Start ngrok: 
    ngrok http 3000
  • Copy the URL ngrok displays. Your app is now exposed at that URL for use with Sonatype Nexus.

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3. Configure Sonatype Nexus to send webhooks

Sonatype Nexus can send webhook requests to your app when events occur in your repository. To register for those events:
  • Sign in to your Sonatype Nexus Repository Manager (the URL depends on where you deployed it).
  • In the left menu, click System, Capabilities, and Create capability on the Capabilities page.
  • Under Select Capability Type, choose Webhook: Global or Webhook: Repository (for this example, Webhook: Global).
  • On Create Webhook, enter your ngrok URL in URL (for example, https://1a2b-3c4d-5e6f-7g8h-9i0j.ngrok.app).
  • In Available, click repository and use the greater-than button to move it to Selected.

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Run webhooks with Sonatype Nexus and ngrok

Sonatype Nexus sends different request body contents depending on the event. To trigger a call to your app:
  • In the Sonatype Nexus UI, click Repository and Repositories, then (for example) apt (hosted).
  • Click Create Repository, choose a Recipe, enter Name, Distribution, and Signing Key, and click Create repository.
Confirm your localhost app receives an event notification and logs both headers and body in the terminal.

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Inspecting requests

ngrok’s Traffic Inspector captures all requests made through your ngrok endpoint to your localhost app. Select any request to view detailed information about both the request and response.
To avoid exposing secrets, accounts only collect traffic metadata by default. You must enable full capture in the Observability section of your account settings to capture complete request and response data.
Use the traffic inspector to:
  • Validate webhook payloads and response data
  • Debug request headers, methods, and status codes
  • Troubleshoot integration issues without adding logging to your app

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Replaying requests

Test your webhook handling code without triggering new events from your service using the Traffic Inspector’s replay feature:
  1. Send a test webhook from your service to generate traffic in your Traffic Inspector.
  2. Select the request you want to replay in the traffic inspector.
  3. Choose your replay option:
    • Click Replay to send the exact same request again
    • Select Replay with modifications to edit the request before sending
  4. (Optional) Modify the request: Edit any part of the original request, such as changing field values in the request body.
  5. Send the request by clicking Replay.
Your local application will receive the replayed request and log the data to the terminal.

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Secure webhook requests

ngrok can verify that incoming requests are from your Sonatype Nexus webhook so only that traffic reaches your app.
Webhook verification is limited to 500 validations per month on free accounts. If you need more, you can upgrade to Hobbyist or Pay-as-you-go. See TPU Pricing for details.
To add verification:
  • In your Sonatype Nexus Repository Manager, go to System, Capabilities, and the webhook capability you created (Webhook: Global or Webhook: Repository).
  • On the Webhook page, open the Settings tab and enter a value in Secret Key (for example, 12345).
  • Create a Traffic Policy file named sonatype_nexus_policy.yml. Replace {your webhook secret} with the Secret Key value: 
    on_http_request:
  - actions:
      - type: verify-webhook
        config:
          provider: sonatype_nexus
          secret: "{your webhook secret}"
  • Restart ngrok with the policy file: 
    ngrok http 3000 --traffic-policy-file sonatype_nexus_policy.yml
  • Trigger an event (for example, create a repository as above) to send a request.
Your app should receive the request and log it in the terminal.