How to create a config file for node pkg

Question

I use node pkg to create a .exe of my nodejs service: https://www.npmjs.com/package/pkg

My question is: how do I make the .exe use a config.js for some setup values? Basic stuff like ip, port, database name etc. Because I have 3 environments, and I would like to use the same exe for all, but different config.js files for each.

So far, if I do pkg app.js then it creates an .exe that doesn't look at any other files. Totally stand alone. How do I make it look at config.js when it is started up?

On the website they do have a section on config https://github.com/zeit/pkg#config but I do not understand how to make use of it. At the moment I have my app.js, and I have secrets.js which holds the config information.

Answer 1

I am not sure this is right way, but I hope this can be helpful to somebody.
Refer to pkg document, on the run time, __dirname becomes "/snapshot/project".

So, by checking __dirname, you can identify in which environment you are.
(node app.js or app.exe).

Then we can separate require sentence like below.

const PKG_TOP_DIR = 'snapshot';

const runInPKG = (function(){
  const pathParsed = path.parse(__dirname);
  const root = pathParsed.root;
  const dir = pathParsed.dir;
  const firstDepth = path.relative(root, dir).split(path.sep)[0];
  return (firstDepth === PKG_TOP_DIR)
})();

let config = require('./appconfig.json');

if(runInPKG) {
  const deployPath = path.dirname(process.execPath);
  config = require(path.join(deployPath, 'appconfig.json'));
}

• Adding above code to your app.js makes some warning when pkg build.

pkg . --targets node8-win-x64 --out-path ./dist

[email protected] Warning Cannot resolve 'path.join(deployPath, 'appconfig.json')'
app.js
Dynamic require may fail at run time, because the requested file
is unknown at compilation time and not included into executable.
Use a string literal as an argument for 'require', or leave it
as is and specify the resolved file name in 'scripts' option.

Answer 2

https://github.com/vercel/pkg/issues/195
use fs to read config file insead of require or import
eg:
const configPath = path.join(process.cwd(), './config/config.json');
lset data = fs.readFileSync(configPath);

same question link:excluding config file while converting node js files to exe using pkg