prometheus-act-exporter/server.js

const http = require("http");
const port = 3000;
const metrics = require("./index");
const promFormatter = require("./prom");

CACHE = {};

const requestHandler = async (req, res) => {
  let date = new Date(Date.now()).toLocaleString();
  console.log(`${date}: ${req.url}`);
  switch (req.url) {
    case "/metrics":
      res.setHeader("Content-Type", promFormatter.contentType);
      metrics.getUsage().then(
        (data) => {
          console.log(data);
          console.log("Setting cache");
          CACHE = data;
          promFormatter.format(data).then((data) => {
            res.end(data);
          });
        },
        (err) => {
          console.log(err);
          console.log("Got error, using cache");
          console.log(CACHE);
          promFormatter.format(CACHE).then((data) => {
            res.end(data);
          });
        }
      );
      break;
    default:
      res.writeHead(302, {
        Location: "https://github.com/captn3m0/prometheus-act-exporter",
      });
      res.end();
      break;
  }
};

const server = http.createServer(requestHandler);

server.listen(port, (err) => {
  if (err) {
    return console.log("could not initialize web server", err);
  }

  console.log(`server is listening on ${port}`);
});