Passing environment variables in npm-scripts

Question

I have a package.json with following (simplified) content in the scripts key:

...
scripts: {
   \"start\": \"NODE_ENV=${NODE_ENV:=production} node start-app.js\"         


        

Answer 1

If you have small use cased, use better-npm-run. For small cases, it works fine. Somehow if you have a lot of commands and it hard manage. Try, batman-cli. Work well and handle lot of environment-dependent issues

npm i -g batman-cli

Answer 2

You have a few options:

• better-npm-run,which can define an env for each command separately
• Instead of a poststart script, you can concatenate commands for npm like so: "start": "NODE_ENV=${NODE_ENV:=production} node start-app.js && echo $NODE_ENV"
• Use a process manager in production like pm2. pm2 lets you define environment specific json files with settings such as NODE_ENV. At our company, we successfully run all of our apps in different environments with pm2 (all the while having the same start command)

Answer 3

this is how I did it, first you need to install two dev-dependencies

https://www.npmjs.com/package/env-cmd this load your env var from your file

https://www.npmjs.com/package/cross-env this use environment variable in script

example scripts:

"env-cmd ./.config/prod.env cross-env-shell \"docker volume create $DOCKER_VOLUME\""

this load $DOCKER_VOLUME env var from prod.env

update: starting from env-cmd version 10, you need specify -f flag if you want to use a custom env file path

"env-cmd -f ./.config/prod.env cross-env-shell \"docker volume create $DOCKER_VOLUME\""