wait-for-http.js

#!/usr/bin/env node
const process = require("process");
const fetch = require("node-fetch");

if (process.argv.length < 3 || process.argv.length > 4) {
  console.error(`Usage: ${process.argv[0]} endpoint timeout`);
  process.exit(2);
}

const endpoint = process.argv[2];
const timeout = parseInt(process.argv[3]) || 10;

const wait = (delay) => {
  return new Promise((r) => setTimeout(r, delay));
};

console.log(`Going to try hitting ${endpoint} for ${timeout} seconds`);

(async () => {
  for(let tries = 0; tries < timeout; tries += 1) {
    try {
      await fetch(endpoint);
      console.log(`${endpoint} is up after ${tries} seconds`);
      process.exit(0);
    } catch (err) {
      if (tries % 15 === 0) {
        console.log(`${endpoint} is not up after ${tries} seconds`);
      }
      await wait(1000);
    }
  }
  console.error(`${endpoint} never came up 😭`);
  process.exit(1);
})();