How to set environment variables from within package.json

问题

How to set some environment variables from within package.json to be used with npm start like commands?

Here\'s what I currently have in my package.json:

{
  ...
  \"scripts\": {
    \"help\": \"tagove help\",
    \"start\": \"tagove start\"
  }
  ...
}

I want to set environment variables (like NODE_ENV) in the start script while still being able to start the app with just one command, npm start.

回答1:

Set the environment variable in the script command:

...
"scripts": {
  "start": "node app.js",
  "test": "NODE_ENV=test mocha --reporter spec"
},
...

Then use process.env.NODE_ENV in your app.

Note: This is for Mac & Linux only. For Windows refer to the comments.

回答2:

Just use NPM package cross-env. Super easy. Works on Windows, Linux, and all environments. Notice that you don't use && to move to the next task. You just set the env and then start the next task. Credit to @mikekidder for the suggestion in one of the comments here.

From documentation:

{
  "scripts": {
    "build": "cross-env NODE_ENV=production OTHERFLAG=myValue webpack --config build/webpack.config.js"
  }
}

Notice that if you want to set multiple global vars, you just state them in succession, followed by your command to be executed.

Ultimately, the command that is executed (using spawn) is:

webpack --config build/webpack.config.js

The NODE_ENV environment variable will be set by cross-env

回答3:

I just wanted to add my two cents here for future Node-explorers. On my Ubuntu 14.04 the NODE_ENV=test didn't work, I had to use export NODE_ENV=test after which NODE_ENV=test started working too, weird.

On Windows as have been said you have to use set NODE_ENV=test but for a cross-platform solution the cross-env library didn't seem to do the trick and do you really need a library to do this:

export NODE_ENV=test || set NODE_ENV=test&& yadda yadda

The vertical bars are needed as otherwise Windows would crash on the unrecognized export NODE_ENV command :D. Dunno about the trailing space but just to be sure I removed them too.

回答4:

Because I often find myself working with multiple environment variables, I find it useful to keep them in a separate .env file (make sure to ignore this from your source control).

VAR_A=Hello World
VAR_B=format the .env file like this with new vars separated by a line break

Then prepend export $(cat .env | xargs) && before your script command.

Example:

{
  ...
  "scripts": {
    ...
    "start": "export $(cat .env | xargs) && echo do your thing here",
    "env": "export $(cat .env | xargs) && env",
    "env-windows": "export $(cat .env | xargs) && set"
  }
  ...
}

For a test you can view the env variables by running npm run env (linux) or npm run env-windows (windows).

回答5:

Try this on Windows by replacing YOURENV:

  {
    ...
     "scripts": {
       "help": "set NODE_ENV=YOURENV && tagove help",
       "start": "set NODE_ENV=YOURENV && tagove start"
     }
    ...
  }

回答6:

suddenly i found that actionhero is using following code, that solved my problem by just passing --NODE_ENV=production in start script command option.

if(argv['NODE_ENV'] != null){
  api.env = argv['NODE_ENV'];
} else if(process.env.NODE_ENV != null){
  api.env = process.env.NODE_ENV;
}

i would really appreciate to accept answer of someone else who know more better way to set environment variables in package.json or init script or something like, where app bootstrapped by someone else.

回答7:

For a larger set of environment variables or when you want to reuse them you can use env-cmd.

./.env file:

# This is a comment
ENV1=THANKS
ENV2=FOR ALL
ENV3=THE FISH

./package.json:

{
  "scripts": {
    "test": "env-cmd mocha -R spec"
  }
}

回答8:

Although not directly answering the question I´d like to share an idea on top of the other answers. From what I got each of these would offer some level of complexity to achieve cross platform independency.

On my scenario all I wanted, originally, to set a variable to control whether or not to secure the server with JWT authentication (for development purposes)

After reading the answers I decided simply to create 2 different files, with authentication turned on and off respectively.

  "scripts": {
    "dev": "nodemon --debug  index_auth.js",
    "devna": "nodemon --debug  index_no_auth.js",
  }

The files are simply wrappers that call the original index.js file (which I renamed to appbootstrapper.js):

//index_no_auth.js authentication turned off
const bootstrapper = require('./appbootstrapper');
bootstrapper(false);

//index_auth.js authentication turned on
const bootstrapper = require('./appbootstrapper');
bootstrapper(true);

class AppBootStrapper {

    init(useauth) {
        //real initialization
    }
}

Perhaps this can help someone else

回答9:

You should not set ENV variables in package.json. actionhero uses NODE_ENV to allow you to change configuration options which are loaded from the files in ./config. Check out the redis config file, and see how NODE_ENV is uses to change database options in NODE_ENV=test

If you want to use other ENV variables to set things (perhaps the HTTP port), you still don't need to change anything in package.json. For example, if you set PORT=1234 in ENV and want to use that as the HTTP port in NODE_ENV=production, just reference that in the relevant config file, IE:

# in config/servers/web.js
exports.production = { 
  servers: {
    web: function(api){
      return {
       port: process.env.PORT
      }
    }
  }
}

回答10:

{
  ...
  "scripts": {
    "start": "ENV NODE_ENV=production someapp --options"
  }
  ...
}

回答11:

This will work in Windows console:

"scripts": {
  "aaa": "set TMP=test && npm run bbb",
  "bbb": "echo %TMP%"
}

npm run aaa

output: test

See this answer for details.

来源：https://stackoverflow.com/questions/25112510/how-to-set-environment-variables-from-within-package-json

标签

node.js

npm

package.json

npm-scripts