@iin-mdc/koa-utils/lib/runner.js

"use strict"

const SIGUSR2 = "SIGUSR2"
const SIGTERM = "SIGTERM"

class Runner {
  constructor(Application, options={}) {
    this.config      = options.config
    this.signals     = options.stopSignals || [SIGUSR2, SIGTERM]
    this.application = new Application(this.config)

    this.assignListeners()
  }

  async start() {
    await this.application.initDependencies()
    await this.application.start()
    this.application.logger.debug("Successfully started!")
  }

  async exit(status=0, signal=SIGTERM, ) {
    let killTimer = setTimeout(() => {
      // eslint-disable-next-line no-console
      console.log("Tired of waiting for gracefull shutdown. Exiting...")
      process.exit(133)
    }, 10000)

    try {
      await this.application.stop()
    } catch(e) {
      // eslint-disable-next-line no-console
      console.log("Error happened during shutdown ", e)
      process.exit(131)
    }

    this.removeListeners()
    clearTimeout(killTimer)
    if (status === 0) {
      process.kill(process.pid, signal)
    } else {
      process.exit(status)
    }
  }

  assignListeners() {
    process.on("unhandledRejection", (reason, p) => {
      // eslint-disable-next-line no-console
      console.log("Possibly Unhandled Rejection at: Promise ", p, " reason: ", reason)
      this.exit(132)
    })

    this.signals.forEach((signal) => process.on(signal, this.exit.bind(this, 0, signal)))
  }

  removeListeners() {
    this.signals.forEach((signal) => process.removeAllListeners(signal))
  }
}

module.exports = Runner