Overview

The Webhook Relay system publishes hooks (from an external webhook based system (e.g. Github / Dockerhub)) to subscribers on an internal network. This is primarily used for secure systems which do not expose their Jenkins instance to the outside world.

There are two components in the webhook-relay universe:

• webhook-relay - Docker container running a Python application that listens for hook events and publishes
• webhook-relay-plugin - Jenkins plugin that connects via websockets to the webhook-relay, downloads the events and then sends them to the Jenkins instance.

webhook-relay

The code for the webhook-relay and information on configuration can be found in

Network Architecture

• Publisher - Github / Dockerhub running on the public network
• Relay - runs on a publically accessible network (e.g. network DMZ)
• Subscriber - Jenkins running the webhook-relay plugin

Protocols

• Publisher to Relay - HTTP or HTTPS
• Relay - the relay is currently a single process that share publish / subscribe duties
• Subscriber to Relay - Websockets over HTTP (WS) or HTTPS (WSS)

Configuration

Start Jenkins with an environment variable WEBHOOK_SUBSCRIPTION which tells the plugin the endpoint to connect to.

See the documentation for the webhook-relay for more information on how this URL is constructed and used.