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webEye - The webhook receiver

When building out the demo environment which I was going to use for our NLVMUG UserCon presentation I came accross a problem: I wanted to notify my private cloud whenever a new Docker image was build on Docker Hub. This proofed impossible with the existing VMware software so I created my own solution. And here it is: webEye - The webhook receiver. It will simply forward all received webhooks to an AMQP bus after checking that it’s a valid webhook message. You can pick up the message with your favourite orchestration tool and act on them.

docker

webEye

Every hook needs an eye to hook into. That’s why my little app is called webEye :) nodejs webEye is written in JavaScript and runs on node.js. It is designed to run in a docker container. However, it already evolved fom something that was originally intended to just receive docker hub webhooks. Currently it also has support for my “Magic Button” and even for vRealize Operations. Other web hook senders might follow.

Getting started

As I said, webEye is developed to run in a docker container so this “getting started” will only cover how to start the app in a docker environment.

  • All received hook are forwarded to an AMQP bus. So let’s start an AMQP Server: docker run –name rabbit -p 5672:5672 -p 15672:15672 dockerfile/rabbitmq
  • Now start webEye: docker run -p 80:80 -p 443:443 -e “DHKEY=12345” -e “MBKEY=12345” –name webEye –link rabbitmq:rabbit -t vchrisr/webeye
  • The DHKEY in the line above sets the API key that you need to send with the request. This adds a bit of security. Make sure to put in a random string instead of “12345”.  tip: random.org
  • Now make sure port 80 on your webEye server is mapped to a public ip address
  • Open the now running webEye page in a browser to to get it running. This first visit actually triggers phusion passenger in the container to start the node.js app. This in turn creates a persistent exchange on the rabbitMQ server.
  • Create a webhook on your docker hub repository to http://{your public ip}:{public port}/dockerhub?apikey=12345
  • Connect your consumer to the rabbitMQ server
  • Create a new Q to receive your messages
  • Create a binding which routes messages with routing key webeye.docker.hub to your Q
  • Create a suscription for the Q you created
  • If you’re using vRO you can now create a policy which triggers a workflow when a message appears in the subscription.
  • Create a workflow that does whatever you want when a docker hub hook is received.

Testing webEye

If you were able to make webEye available on the public internet and you’ve configured a webhook on your docker repo you can

  • now simply click “test” on the webhook configuration page.
  • To test offline I usually use the Firefox RESTClient plugin.Select “POST” as the method.
  • Enter this url: http://:/dockerhub?apikey=
  • Add this header: Content-Type: application/json
  • For the body you need some actual content. webEye will check the presence of some specific fields in the json to make sure it’s a Docker Hub webhook. I usually use the json from the Docker Hub Documentation:
  • {
    "callback\_url": "https://registry.hub.docker.com/u/svendowideit/busybox/hook/2141bc0cdec4hebec411i4c1g40242eg110020/",
    "push\_data": {
        "images": \[
            "27d47432a69bca5f2700e4dff7de0388ed65f9d3fb1ec645e2bc24c223dc1cc3",
            "51a9c7c1f8bb2fa19bcd09789a34e63f35abb80044bc10196e304f6634cc582c"
        \],
        "pushed\_at": 1417566822,
        "pusher": "svendowideit"
    },
    "repository": {
        "comment\_count": 0,
        "date\_created": 1417566665,
        "description": "",
        "full\_description": "webhook triggered from a 'docker push'",
        "is\_official": false,
        "is\_private": false,
        "is\_trusted": false,
        "name": "busybox",
        "namespace": "svendowideit",
        "owner": "svendowideit",
        "repo\_name": "svendowideit/busybox",
        "repo\_url": "https://registry.hub.docker.com/u/svendowideit/busybox/",
        "star\_count": 0,
        "status": "Active"
    }
}

resttest-webeye