autobounty/index.js

123 lines
3.7 KiB
JavaScript

/*
* Bot that receives a POST request (from a GitHub issue comment webhook)
* and in case it's a comment that has "@autobounty <decimal> <currency>"
* awards that bounty to the address posted earlier in the thread (by the
* commiteth bot).
* TODO tests
* REVIEW parsing, non-persisting storage of addresses, hardcoded string length.
* Depends on commiteth version as of 2017-06-10.
*/
const config = require('./config');
const bot = require('./bot');
const crypto = require('crypto');
var express = require('express'),
cors = require('cors'),
helmet = require('helmet'),
app = express(),
bodyParser = require('body-parser'),
jsonParser = bodyParser.json();
app.use(cors());
app.use(helmet());
// Receive a POST request at the url specified by an env. var.
app.post(`${config.urlEndpoint}`, jsonParser, function (req, res, next) {
if (!req.body || !req.body.action) {
return res.sendStatus(400);
} else if (!bot.needsFunding(req)) {
return res.sendStatus(204);
}
validation = validateRequest(req);
if (validation.correct) {
setTimeout(() => {
processRequest(req)
.then(() => {
bot.info('issue well funded: ' + req.body.issue.url);
})
.catch((err) => {
bot.error('Error processing request: ' + req.body.issue.url);
bot.error('Error: ' + err);
bot.error('Dump: ', req.body);
});
}, config.delayInMiliSeconds);
} else {
bot.error('Error validating issue: ' + req.body.issue.url);
bot.error('Error: ' + validation.error);
}
return res.sendStatus(200);
});
const validateRequest = function (req) {
validation = {correct: false, error: ''};
webhookSecret = process.env.WEBHOOK_SECRET;
if(!webhookSecret) {
validation.error = 'Github Webhook Secret key not found. ' +
'Please set env variable WEBHOOK_SECRET to github\'s webhook secret value';
} else {
const blob = JSON.stringify(req.body);
const hmac = crypto.createHmac('sha1', webhookSecret);
const ourSignature = `sha1=${hmac.update(blob).digest('hex')}`;
const theirSignature = req.get('X-Hub-Signature');
const bufferA = Buffer.from(ourSignature, 'utf8');
const bufferB = Buffer.from(theirSignature, 'utf8');
const safe = crypto.timingSafeEqual(bufferA, bufferB);
if (safe) {
validation.correct = true;
} else {
validation.error = 'Invalid signature. Check that WEBHOOK_SECRET ' +
'env variable matches github\'s webhook secret value';
}
}
return validation;
}
const processRequest = function (req) {
// const wallet = bot.wallet;
const from = config.sourceAddress;
const to = bot.getAddress(req);
// Asynchronous requests for Gas Price and Amount
const amountPromise = bot.getAmount(req);
const gasPricePromise = bot.getGasPrice();
return new Promise((resolve, reject) => {
Promise.all([amountPromise, gasPricePromise])
.then(function (results) {
let amount = results[0];
let gasPrice = results[1];
bot.sendTransaction(to, amount, gasPrice)
.then(function () {
resolve();
})
.catch(function (err) {
reject(err);
});
})
.catch(function (err) {
reject(err);
});
});
}
const port = process.env.PORT || 8181
app.listen(port, function () {
bot.info('Autobounty listening on port', port);
});