ngenv/ngenv

#!/usr/bin/env node
const ngrok = require("ngrok");
const fs = require("fs");
const os = require("os");
const { parse } = require("yaml");

// Parse the command line options
const commandLineArgs = require("command-line-args");
const optionDefinitions = [
  { name: "proto", alias: "P", type: String },
  { name: "port", alias: "p", type: Number },
  { name: "env", alias: "e", type: String },
];
const options = commandLineArgs(optionDefinitions);
const dotenvFile = options?.env ?? "./.env";

// vars
let authToken = null; // string || null

// Main (an async) function
(async function () {
  // Get the ngrok config file path
  let ngrokConfig = getNgrokConfig();

  // Check if the ngrok config file exists
  if (!fs.existsSync(ngrokConfig)) {
    throw new Error("No ngrok config file found");
  }

  // Read the ngrok config file
  try {
    const { authToken } = readNgrokConfig(ngrokConfig);
    global.authToken = authToken;
  } catch (err) {
    console.error(err);
    process.exit(1);
  }

  // Start ngrok
  const proto = options?.proto ?? "http";
  const addr = options?.port ? options.port : 3000;
  try {
    const url = await ngrok.connect({
      authtoken: authToken,
      proto,
      addr,
      onLogEvent: (data) => {
        // combine the key-value pairs into a single object
        const dataObj = parseLogLine(data);
        // console.log(`[${dataObj.lvl}] ${dataObj.msg}`);
        // console.log(dataObj);
      },
    });
    writeDotEnv(url); // Sync the .env file
    console.log(`Started ngrok: protocol '${proto}', addr '${addr}'`);
    console.log(`Your current ngrok url is ${url}.`);
    console.log(`Your .env file has been updated.`);
  } catch (err) {
    console.error(err.message);
    process.exit(1);
  }
})(); // end main async function

function getNgrokConfig() {
  // Newer versions of ngrok
  let ngrokConfig = os.homedir() + "/.ngrok2/ngrok.yml";
  if (fs.existsSync(ngrokConfig)) {
    return ngrokConfig;
  }

  // Alternative location for linux
  ngrokConfig = os.homedir() + "/.config/ngrok/ngrok.yml";
  if (fs.existsSync(ngrokConfig)) {
    return ngrokConfig;
  }

  // MacOS
  ngrokConfig = os.homedir() + "/Library/Application Support/ngrok/ngrok.yml";
  if (fs.existsSync(ngrokConfig)) {
    return ngrokConfig;
  }

  // Windows
  ngrokConfig = os.homedir() + "/AppData/Local/ngrok/ngrok.yml";
  if (fs.existsSync(ngrokConfig)) {
    return ngrokConfig;
  }

  throw new Error("ngrok config file not found");
}

function readNgrokConfig(ngrokConfig) {
  const data = fs.readFileSync(ngrokConfig, "utf8");

  let authToken;

  // Convert string to string array, split at newlines
  let lines = data.split("\n"); // string[]

  // find the auth token (format: authtoken: token_goes_here)
  lines.forEach((element) => {
    const [name, value] = element.split(": ");
    if (name === "authtoken") authToken = value;
  });

  // No token found
  if (!authToken) {
    // https://dashboard.ngrok.com/get-started/your-authtoken
    throw new Error("Setup NGROK_AUTHTOKEN in your .env file");
  }

  return { authToken };
}

function readDotEnv() {
  const data = fs.readFileSync(dotenvFile, "utf8");

  // Convert string to string array, split at newlines
  let lines = data.split("\n"); // string[]

  return lines;
}

function writeDotEnv(url) {
  // Read the .env file
  let lines = readDotEnv(dotenvFile);

  // Rebuild lines with the new url
  let found = false;
  lines = lines.map((element) => {
    const [name] = element.split("=");
    if (name === "NGROK_SERVERHOST") {
      found = true;
      return `${name}=${url}`;
    }
    return element;
  });

  // Is this variable already in the .env, if not add it.
  if (!found) {
    lines.unshift(`NGROK_SERVERHOST=${url}`);
  }

  // convert back to string format
  let writeData = "";
  lines.forEach((element) => {
    writeData += element + "\n";
  });
  writeData = writeData.slice(0, writeData.length - 1);

  // Write the new .env file
  fs.writeFileSync(dotenvFile, writeData);
}

function parseLogLine(line) {
  const regex = /(\S+)=("[^"]+"|\S+)/g;
  const logEntry = {};
  let match;
  while ((match = regex.exec(line)) !== null) {
    logEntry[match[1]] = match[2].replace(/"/g, "");
  }
  logEntry.t = new Date(logEntry.t);
  return logEntry;
}