问题
How do I set the value of process.env.SOME_KEY=some value in the operating system and then read it in my node application? I am running on Windows.
I tried these steps:
SET SOME_KEY=abc
npm start
But when I try to read process.env.SOME_KEY, I am getting "undefined".
How do I set a env value and how do i read that in my code?
回答1:
Try this: https://www.npmjs.com/package/dotenv
All you need to do is add a .env with your environment variables, and require('dotenv').config() as soon as you can in your application (the script called by npm start would be a good place)
回答2:
SOME_KEY=`${abc}` Fixed it for me.
回答3:
The npm module cross-env was made exactly for this purpose. The way you set an environment variable is not same across all the OSes. cross-env solves this.
Else, you can also try dotenv that solves this with a .env file.
You can also do this at the very basic level:
process.env.SOME_KEY = "somevalue";
回答4:
Add this in index file
require('dotenv').config({path: path.join(__dirname, '.env')});
来源：https://stackoverflow.com/questions/48932751/process-env-some-key-is-undefined