What is webhook?

webhook is a lightweight configurable tool written in NodeJS, that allows you to easily create HTTP endpoints (hooks) on your server, which you can use to execute configured commands. You can also pass data from the HTTP request (such as headers, payload or query variables) to your commands. webhook also allows you to specify rules which have to be satisfied in order for the hook to be triggered.

For example, if you're using Github or Bitbucket, you can use webhook to set up a hook that runs a redeploy script for your project on your staging server, whenever you push changes to the master branch of your project.

If you use Mattermost or Slack, you can set up an "Outgoing webhook integration" or "Slash command" to run various commands on your server, which can then report back directly to you or your channels using the "Incoming webhook integrations", or the appropriate response body.

webhook aims to do nothing more than it should do, and that is:

1. receive the request,
2. parse the headers, payload and query variables,
3. check if the specified rules for the hook are satisfied,
4. and finally, pass the specified arguments to the specified command via command line arguments or via environment variables.

Everything else is the responsibility of the command's author.

Getting started

Installation

Install it with npm

npm install -g webhook-cli

Configuration

Next step is to define some hooks you want webhook to serve. Begin by creating an empty file named hooks.json. This file will contain an array of hooks the webhook will serve. Check Hook definition page to see the detailed description of what properties a hook can contain, and how to use them.

Let's define a simple hook named redeploy-webhook that will run a redeploy script located in /var/scripts/redeploy.sh.

Our hooks.json file will now look like this:

[
  {
    "id": "redeploy-webhook",
    "execute-command": "/var/scripts/redeploy.sh",
    "command-working-directory": "/var/webhook"
  }
]

You can now run webhook using

$ webhook --hooks hooks.json -verbose

It will start up on default port 9000 and will provide you with one HTTP endpoint

http://yourserver:9000/hooks/redeploy-webhook

Check webhook parameters page to see how to override the ip, port and other settings such as hook hotreload, verbose output, etc, when starting the webhook.

By performing a simple HTTP GET or POST request to that endpoint, your specified redeploy script would be executed. Neat!

However, hook defined like that could pose a security threat to your system, because anyone who knows your endpoint, can send a request and execute your command. To prevent that, you can use the "trigger-rule" property for your hook, to specify the exact circumstances under which the hook would be triggered. For example, you can use them to add a secret that you must supply as a parameter in order to successfully trigger the hook. Please check out the Hook rules page for detailed list of available rules and their usage.

Using HTTPS

webhook by default serves hooks using http. If you want webhook to serve secure content using https, you can use the --secure flag while starting webhook. Files containing a certificate and matching private key for the server must be provided using the --cert /path/to/cert.pem and --key /path/to/key.pem flags. If the certificate is signed by a certificate authority, the cert file should be the concatenation of the server's certificate followed by the CA's certificate.

CORS Headers

If you want to set CORS headers, you can use the --header name=value flag while starting webhook to set the appropriate CORS headers that will be returned with each response.

Examples

Check out Hook examples page for more complex examples of hooks.

Note

There is go version webhook, it's awesome and you can try it. I just rewrite that webhook in NodeJS, the concepts, config and doc is almost same.

License

The MIT License (MIT)

Copyright (c) 2017 sigoden [email protected]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.