add multiple support

[excaliburhan]

multiple handlers

I need multiple handlers for different repos and I hope those handlers have different secret for each repo. And those handlers only take one port.

So I make options.secret to support both string and object. If options.secret is an object, the key of the object will be appId, and the value of the object will be appSecret. At last, the EmitData will return the appId for use.

---

Here's the example for multiple handlers:

// handler settings
var handler = createHandler({
  path: '/app',
  secret: {
    app1: 'secret1',
    app2: 'secret2'
  }
})
// server
http.createServer(function (req, res) {
  handler(req, res, function (err) {
    res.statusCode = 404
    res.end('no such location')
  })
}).listen(7777)
// events
handler.on('push', function (event) {
  var appId = event.appId
  switch (appId) {
    case 'app1':
      // do sth about app1
      break
    case 'app2':
      // do sth about app2
      break
    default:
      break
  }
})

And in github Webhooks Payload URL:

app1

http://example.com/app?id=app1

app2

http://example.com/app?id=app2

---

If options.secret is a string, everything remains the same.

[rjz]

Thanks, @excaliburhan! This PR covers a fairly specific scenario as written, but I wonder if we could expand it to accommodate the scenarios in #16 ("add additional fields to emitData") and #21 ("enable multiple handlers").

If we allowed consumers to provide their own validation/parsing logic--or even separated webhook processing from the HTTP server itself--we could preserve the existing (simple) default but open the door for more customization downstream.

Thoughts?

[excaliburhan]

OK, I realize this PR is actually 'One handler deals with multiple webhooks'.

Solution A: expand
Support multiple path && secret to enable real multiple handlers, like this:

var createHandler = require('github-webhook-handler')
var handler = createHandler([
{ path: '/app1', secret: 'secret1' },
{ path: '/app2', secret: 'secret2' }
])

this solution means we have to rewrite the handler function in github-webhook-handler.js

---

Solution B: process over the HTTP server

var handlerA = createHandler({ path: '/app1', secret: 'secret1' })
var handlerB = createHandler({ path: '/app2', secret: 'secret2' })

http.createServer(function (req, res) {
  // process logic
  switch (req.url) {
    case '/app1':
      handlerA(req, res, function (err) {
        res.statusCode = 404
        res.end('no such location')
      })
      break
    case '/app2':
      handlerB(req, res, function (err) {
        res.statusCode = 404
        res.end('no such location')
      })
      break
    default:
      break
  }
}).listen(7777)

// events
handlerA.on('issues', function(event) {
    // do sth
})
handlerB.on('issues', function(event) {
    // do sth
})

this solution contains consumers' own process logic.

---

I prefer the Solution A, it may make the github-webhook-handler.js a little complicated, but for consumers, it's more convenient.

For Solution B, what makes me unhappy is I have to write many nearly same code to keep different handlers work.

I'd like to help with Solution A.

@rjz what do you think about this?

[rjz]

It seems like we could write A in terms of B, something like:

function multiHook(handlerOpts) { // it's a silly name :^)
  var handlers = handlerOpts.reduce(function (hs, opts) {
    hs[opts.path] = createHandler(opts);
    return hs;
  }, {});

  return http.createServer(function (req, res) {
    var handler = handlers[req.url];
    handler(req, res, function (err) {
      res.statusCode = 404
      res.end('no such location')
    });
  });
}

If that's reasonable, maybe it's appropriate to leave this handler focused on a single hook but either:

• add an example for the multi-app case here
• create a new package (ala github-webhook) tailored to the multi-app case

[excaliburhan]

Cool.
I think we could close this PR now:)

[excaliburhan]

One more thing, in github webhooks settings, the content-type must be application/json rather than application/x-www-form-urlencoded.

I think this tip should be written in the READEME.md.

Just a suggestion.

[rjz]

Done, and big thanks for your suggestions on this, @excaliburhan!

• README.md: great point, will add (or be happy to merge a PR)
• Also, if you're up to add an example to this repo or to link up an external package, it would be awesome to have a reference for other folks with this issue

[excaliburhan]

ok, here's the multi handlers complete example(have tested on my server), and an external package node-github-webhook.

example for github-webhook-handler

function generaterHandler(handlerOpts) {
  var handlers = handlerOpts.reduce(function(hs, opts) {
    hs[opts.path] = createHandler(opts)
    return hs
  }, {})

  return http.createServer(function(req, res) {
    var handler = handlers[req.url]
    handler(req, res, function(err) {
      res.statusCode = 404
      res.end('no such location')
    })
  }).listen(7777)
}

var http = require('http')
var createHandler = require('github-webhook-handler')
var handlerOpts = [{
  path: '/app1',
  secret: 'secret1'
}, {
  path: '/app2',
  secret: 'secret2'
}]
var handler = generaterHandler(handlerOpts)

handler.on('error', function(err) {
  console.error('Error:', err.message)
})
handler.on('push', function (event) {
  var url = event.url
  switch (url) {
    // be careful if you use query to distinguish your app, url contains the querys, otherwise, it is equal to the path
    case '/app1':
      // do sth for app1
      break
    case '/app2':
      // do sth for app2
      break
    default:
      break
})

example for node-github-webhook

var http = require('http')
var createHandler = require('node-github-webhook')
var handler = createHandler([{
    path: '/app1',
    secret: 'secret1'
  },
  {
    path: '/app2',
    secret: 'secret2'
  }
])

http.createServer(function (req, res) {
  handler(req, res, function (err) {
    res.statusCode = 404
    res.end('no such location')
  })
}).listen(7777)

// handler
handler.on('error', function (err) {
  console.error('Error:', err.message)
})
handler.on('push', function (event) {
  var path = event.path
  switch (path) {
    case '/app1':
      // do sth for app1
      break
    case '/app2':
      // do sth for app2
      break
    default:
      break
  }
})