index.js

const debug = require('debug')('vhs-hookhub-github-nomos')
debug('Loading vhs-hookhub-github-nomos')
debug(__dirname)

const express = require('express')
const router = express.Router()
const config = require('./config.json')
const { xHubSignatureMiddleware } = require('x-hub-signature-middleware')
const smb = require('slack-message-builder')

// Perform sanity check
router.use(function (req, res, next) {
    if (
        req.header('X-Hub-Signature') == null ||
        req.header('X-Hub-Signature').length < 40 ||
        req.header('X-GitHub-Event') == undefined ||
        req.header('X-GitHub-Event') == '' ||
        req.rawBody == undefined
    ) {
        res.status(412).send({
            result: 'ERROR',
            message: 'Missing or invalid request arguments'
        })
    } else {
        next()
    }
})

// Check X-Hub-Signature
router.use(
    xHubSignatureMiddleware({
        algorithm: 'sha1',
        secret: config.github.secret,
        require: true,
        getRawBody: (req) => req.rawBody
    })
)

/* Default handler. */
router.use('/', async function (req, res, next) {
    debug('Handling default request')

    let post_body = generateMessage(req.header('X-GitHub-Event'), req.body)

    debug('post_body:', post_body)

    const post_options = {
        method: 'POST',
        body: JSON.stringify(post_body)
    }

    try {
        const data = await (await fetch(config.slack.url, post_options)).json()

        res.send({
            result: 'OK',
            message: data
        })
    } catch (err) {
        res.status(500).send({
            result: 'ERROR',
            message: err
        })
    }
})

module.exports = router

const generateMessage = function (event_type, payload) {
    let slack_message = smb()
        .username(config.slack.options.username)
        .iconEmoji(config.slack.options.icon_emoji)
        .channel(config.slack.options.channel)

    if (event_type === 'push') {
        payload.commits.forEach(function (commit) {
            slack_message = slack_message
                .text("The following commit(s) got pushed to '" + payload.repository.name + "':\r\r")
                .attachment()
                .fallback('Required plain-text summary of the attachment.')
                .color('#0000cc')
                .authorName(payload.sender.login)
                .authorLink(payload.sender.html_url)
                .authorIcon(payload.sender.avatar_url)
                .title('Commit: ' + commit.id)
                .titleLink(commit.url)
                .text(commit.message)
                .footer('Via: vhs-hookhub-github-nomos')
                .ts(Math.round(Date.parse(commit.timestamp) / 1000))
                .end()
        })
    } else {
        slack_message = slack_message.text(
            "We received a new '" +
                event_type +
                "' notification for '" +
                payload.repository.name +
                "', but we didn't know what to do with this event!"
        )
    }

    return slack_message.json()
}