Cptn

Cptn is a quick and easy web server that responds to POST requests containing JSON data. It’s meant for use with GitLab webhooks.

Usage

var captain = require('cptn')(9000);
captain.hook('myproject/push', { cwd: '.' }, 'echo "Push received" >> captains-log');
captain.hook('myproject/merge-request', function (data, done) { console.log(data); done(); });

This starts a new Cptn server, makes it listen on port 9000 (a Unix socket can be used instead by passing a string) and attaches two hooks: myproject/push and myproject/merge.

myproject/push will be called when sending a POST request to localhost:9000/myproject/push. It will run the provided unix command.

myproject/merge-request will be called when sending a POST request to localhost:9000/myproject/merge-request. It will log the received data (the JSON body of the POST request).

You can try it with these curl commands:

curl -H "Content-type: application/json" -X POST -d '{}' http://localhost:9000/myproject/push
curl -H "Content-type: application/json" -X POST -d '{"foo": "bar"}' http://localhost:9000/myproject/merge-request

API Documentation

Cptn(port, options)

Starts a new Cptn server and listens on the specified port (a port number or Unix socket name).

Returns a Cptn server instance.

Accepts the following arguments:

• port (required) A port number or socket to listen on.
• options (optional) An object with the following options:
  • debug (optional, defaults to false) Whether to log debug output to the console.

captain#hook(url[, options], action)

Attaches a hook that will call the specified action each time a POST request is sent to the path specified with name.

Returns nothing.

Accepts the following arguments:

• url (required) A url at which the hook can be reached. No leading slash.
• options (optional) An object that will be passed to child_process.exec() if a Unix command is specified as the action. Currently ignored if a callback is passed as action, but may be used in future versions.
• action (required) An action that will be called upon a POST request to the specified url. Can be a string, in which case it will be passed – together with the options object – to child_process.exec() or a function with the signature (data, callback). data will contain the body of the POST request. callback() should be called when you're done doing what you had to do. It currently has no effect but most likely will in future versions.

Server Behaviour

The server currently responds with a status code and an empty body. It returns 200 (OK) when a hook was found and successfully invoked, 404 (Not Found) when no hook was found, 405 (Method Not Allowed) when the request was not a POST request, 400 (Bad Request) when the body is not valid JSON, and 500 (Internal Server Error) when there was a problem invoking the hook.

To Do

• Write tests
• Add support for basic middleware if needed (but keep it simple)
• Allow regular expressions as URLs if needed