Application server using configmap reload

app.js

// @ts-check

const express = require("express");
const app = express();
const fs = require("fs");
const bodyParser = require('body-parser');

const mountPath = "/etc/config";
const configMapFile = "..data";

function readConfig() {
  const dir = fs.readdirSync(`${mountPath}/${configMapFile}`);

  console.log(`Available envar: ${dir}`);

  dir.forEach(env => {
    process.env[env] = fs.readFileSync(
      `${mountPath}/${configMapFile}/${env}`
    );
  });
}

app.get("/info", (req, res) => {
  res.sendStatus(200);
});

app.use(bodyParser.json());

// configmap reload webhook
app.post("/-/reload", (req, res) => {
  // read new ConfigMap value
  readConfigMap();

  console.log(`process.env AFTER: ${JSON.stringify(process.env)}`);

  res.sendStatus(200);
});

app.get("/isMaintenance", (req, res) => {
  const isMaintenace = process.env.ENV_IS_MAINTENANCE;

  res.status(200).send(`Is it maintenance? ${isMaintenace}`);
})

app.listen(3000, err => {
  if (err) {
    console.error(err);
    process.exit(1);
  }

  console.log(`Server is up on port 3000`);
});