healthcheck.js

import nodemailer from 'nodemailer'
import axios from 'axios'

const serviceURL = process.env.HEALTH_CHECK_SERVICE_URL
const serviceName = process.env.HEALTH_CHECK_SERVICE_NAME
const shouldPostToWebHook = process.env.HEALTH_CHECK_WEB_HOOK
const shouldSendEmail =
  process.env.HEALTH_CHECK_SMTP_HOST &&
  process.env.HEALTH_CHECK_SMTP_USER &&
  process.env.HEALTH_CHECK_SMTP_PASS &&
  process.env.HEALTH_CHECK_EMAIL_FROM &&
  process.env.HEALTH_CHECK_EMAIL_RECIPIENT

axios
  .get(serviceURL)
  .then(async function (response) {
    try {
      const body = response.data
      if (body.healthy === true) {
        process.exit(0)
      }
      await notify(`${serviceName} is unhealthy: ${body.error}`)
      process.exit(1)
    } catch (error) {
      await notify(
        `${serviceName} is potentially unhealthy - error: ${JSON.stringify(error)}`
      )
      process.exit(1)
    }
  })
  .catch(async (error) => {
    await notify(
      `${serviceName} is unhealthy and will restart after 3 tries. Error: ${error.message}`
    )
    process.exit(1)
  })

async function notify(message) {
  console.log(message)
  if (shouldSendEmail) await sendMail(message)
  if (shouldPostToWebHook) await postToWebHook(message)
}

async function postToWebHook(text) {
  await axios
    .post(process.env.HEALTH_CHECK_WEB_HOOK, { text })
    .catch((error) => {
      console.error(error)
    })
}

async function sendMail(message) {
  const messageParams = {
    from: process.env.HEALTH_CHECK_EMAIL_FROM,
    to: process.env.HEALTH_CHECK_EMAIL_RECIPIENT,
    subject: process.env.HEALTH_CHECK_EMAIL_SUBJECT,
    text: message
  }

  const mailTransport = {
    host: process.env.HEALTH_CHECK_SMTP_HOST,
    auth: {
      user: process.env.HEALTH_CHECK_SMTP_USER,
      pass: process.env.HEALTH_CHECK_SMTP_PASS
    },
    ...(process.env.HEALTH_CHECK_SMTP_PORT && {
      port: process.env.HEALTH_CHECK_SMTP_PORT
    })
  }

  const transporter = nodemailer.createTransport(mailTransport)

  try {
    await transporter.sendMail(messageParams)
  } catch (error) {
    console.log('the email send error: ')
    console.log(error)
  }
}

//import * as http from 'node:http';
/* const options = { hostname: 'SIGNER', port: (process.env.PORT || 4006), path: '/healthz', method: 'GET' };

http
    .request(options, (res) => {
        let body = '';

        res.on('data', (chunk) => {
            body += chunk;
        });

        res.on('end', async () => {
            try {
                const response = JSON.parse(body);
                if (response.healthy === true) {
                    console.log('healthy response received: ', body);
                    await sendMail("It worked!")
                    process.exit(0);
                }

                console.log('Unhealthy response received: ', body);
                await sendMail(`It worked, but with error: ${JSON.stringify(body)}`)
                process.exit(1);
            } catch (err) {
                console.log('Error parsing JSON response body: ', err);
                process.exit(1);
            }
        });
    })
    .on('error', (err) => {
        console.log('Error: ', err);
        process.exit(1);
    })
    .end(); */