oneuptime/Scripts/Install/ReplaceValueInConfig.js

// This script merges config.env.tpl to config.env

const fs = require("fs");

const init = () => {
  let env = "";
  try {
    env = fs.readFileSync("./config.env", "utf8");
  } catch (err) {
    // do nothing.
  }
  const envValToReplace = process.argv[2];

  if (!envValToReplace) {
    // eslint-disable-next-line
        console.log('Please have env var to replace');
    return;
  }

  const envValToReplaceWith = process.argv[3];

  if (!envValToReplaceWith) {
    // eslint-disable-next-line
        console.log('Please have env var to replace with');
    return;
  }

  const linesInEnv = env.split("\n");
  const linesToRender = [];
  let found = false;

  for (let line of linesInEnv) {
    // this is a comment, ignore.
    if (!line.startsWith(envValToReplace)) {
      linesToRender.push(line);
    } else {
      found = true;
      const items = line.split("=");
      items[1] = envValToReplaceWith;
      line = items.join("=");
      linesToRender.push(line);
    }
  }

  if (!found) {
    linesToRender.push(envValToReplace + "=" + envValToReplaceWith);
  }

  // write the file back to disk and exit.
  fs.writeFileSync("./config.env", linesToRender.join("\n"));
};

init();