app/env/setupEnv.mjs

/**
 * Post install script: create or replace the symlink .env
 * to the .env file matching the current environment
 *
 * To force an hostname, define an env variable named HOST :
 *
 *     HOST=ci node ./env/setupEnv.mjs
 *
 */
import os from "os";
import fs from "fs";
import {fileURLToPath} from "node:url";
import path from 'path';


const projectDir = path.join(path.dirname(fileURLToPath(import.meta.url)), '..')

const hostname = process.env.HOST ?? os.hostname()

const environments = {
    'app': '.env.docker',
    'prod-v2': '.env.prod',
    'test-v2': '.env.test',
    'test1': '.env.test1',
    'test2': '.env.test2',
    'test3': '.env.test3',
    'test4': '.env.test4',
    'test5': '.env.test5',
    'ci': '.env.ci',
}

if (!environments.hasOwnProperty(hostname)) {
    throw Error("Critical : unknown environment [" + hostname + "]")
}

const targetEnvFile = path.join(projectDir, 'env', environments[hostname])
const mainEnvFile = path.join(projectDir, '.env')

fs.unlink(mainEnvFile, (err) => {
    // 'ENOENT' is the error code for "no such file or directory", we ignore this one
    if (err && err.code !== 'ENOENT') {
        throw err
    }
    console.log(`${mainEnvFile} was deleted`);
});

fs.symlink(
    targetEnvFile,
    '.env',
    'file',
    (err) => {
        if (err) {
            throw (err);
        }
        console.log(`Symlink created : ${mainEnvFile} -> ${targetEnvFile}`)
    }
)