management.js

/* eslint-disable no-console */
const config = require("config");
const express = require("express");
const chalk = require("chalk");
const bodyParser = require("body-parser");
const yarn = require("yarn-api");
const pm2 = require("pm2");
const util = require("util");

const yarnPromise = util.promisify(yarn);

const jsonParser = bodyParser.json();

console.log(chalk.yellow("Starting Thinglator management API"));

// load and initialise express
const app = express();

const delay = t =>
  new Promise(resolve => {
    setTimeout(resolve, t);
  });

const pm2Restart = packageId =>
  new Promise((resolve, reject) => {
    pm2.restart(packageId, (err, apps) => {
      if (err) {
        reject(err);
        return;
      }
      resolve(apps);
    });
  });

const pm2GetInfo = packageId =>
  new Promise((resolve, reject) => {
    pm2.describe(packageId, (err, describeInfo) => {
      if (err) {
        reject(err);
        return;
      }
      resolve(describeInfo);
    });
  });

const installDriver = async driverId => {
  await yarnPromise(["add", `thinglator-driver-${driverId}`]);
  await pm2Restart(config.get("pm2.thinglatorId"));
  await delay(3000);
  const info = await pm2GetInfo(config.get("pm2.thinglatorId"));

  if (info[0].pm2_env.unstable_restarts > 0) {
    throw new Error("Install failed");
  }
};

const uninstallDriver = async driverId => {
  await yarnPromise(["remove", `thinglator-driver-${driverId}`]);
  await pm2Restart(config.get("pm2.thinglatorId"));
  await delay(3000);
  const info = await pm2GetInfo(config.get("pm2.thinglatorId"));

  if (info[0].pm2_env.unstable_restarts > 0) {
    throw new Error("Install failed");
  }
};

// setup the HTTP API
app.get("/", (req, res) => {
  res.json({
    "Thinglator Management": "Oh, hi!"
  });
});

app.post("/install", jsonParser, async (req, res) => {
  try {
    const body = req.body;
    if (!body.driverId) {
      throw new Error("driverId not specified");
    }
    await installDriver(body.driverId);

    res.json({ success: true });
  } catch (err) {
    res.status(400);
    console.error(err);
    res.json({
      message: err.message
    });
  }
});

app.post("/uninstall", jsonParser, async (req, res) => {
  try {
    const { body } = req;
    if (!body.driverId) {
      throw new Error("driverId not specified");
    }
    await uninstallDriver(body.driverId);

    res.json({ success: true });
  } catch (err) {
    res.status(400);
    console.error(err);
    res.json({
      message: err.message
    });
  }
});

// Initialise the webserver
app.listen(config.get("management.port"), () => {
  console.log(
    chalk.blue(
      `REST API server listening on port ${config.get("management.port")}`
    )
  );
});