healthcheck.js

/* Simple http request to localhost. Avoids depending on curl */
const http = require('http')
const defaults = {
    hostname: 'localhost',
    protocol: 'http:',
    method: 'GET',
    port: process.env.HTTP_PORT || 8001,
    headers: {}
}

/**
 *
 * @param {*} args
 */
function check(args) {
    return new Promise((resolve, reject) => {
        let body = args.body || false
        if (args.body) delete args.body

        const req_args = Object.assign(defaults, args)
        // https://github.com/dherault/serverless-offline/issues/610
        if (req_args.method.toLowerCase() == 'get') {
            req_args.headers[ 'Content-Length' ] = 0
        }

        console.log('Request: %O', req_args)
        const req = http.request(req_args, res => {
            let body = ''
            res.on('data', data => (body += data))
            res.on('error', err => reject(err))
            res.on('end', () => {
                console.log('Status code: %s', res.statusCode)
                console.log('Body: %O', body)
                if (args.expected_status_code && res.statusCode != args.expected_status_code) {
                    throw new Error(`HTTP request did not return (${res.statusCode}) the expected status code (${args.expected_status_code}):  ${body.toString()}`)
                }
                const resolver = Object.assign({ statusCode: res.statusCode, body: body }, res.headers)
                resolve(resolver)
            })
        })
        if (args.headers) {
            Object.keys(args.headers)
                .filter(header => typeof args.headers[ header ] != 'undefined')
                .forEach(header => req.setHeader(header, args.headers[ header ]))
        }

        if (body) {
            req.write(JSON.stringify(body), 'utf8')
        }
        req.end()

        req.on('error', err => {
            console.log('Error %O', err)
            reject(err)
        })
    })
}

try {
    check({
        path: '/version'
    }).then(() => {
        process.exit(0)
    })
} catch (error) {
    process.exit(1)
}