Question

我有一个.env文件，看起来像：

NODE_ENV = local
PORT = 4220
BASE_URL = "http://198.**.**.**:4220/"

PROFILE_UPLOAD = http://198.**.**.**:4220/uploads/profile/
POST_UPLOAD = http://198.**.**.**:4220/uploads/discussion/
COMPANY_UPLOAD = http://198.**.**.**:4220/uploads/company/
ITEM_UPLOAD  = http://198.**.**.**/uploads/item/
GROUP_UPLOAD  = http://198.**.**.**/uploads/group/

我想做这样的事情：

NODE_ENV = local
IP = 198.**.**.**
PORT = 5000
BASE_URL = http://$IP:$PORT/

PROFILE_UPLOAD = $BASE_URL/uploads/profile/
POST_UPLOAD = $BASE_URL/uploads/discussion/
COMPANY_UPLOAD = $BASE_URL/uploads/company/
ITEM_UPLOAD  = $BASE_URL/uploads/item/
GROUP_UPLOAD  = $BASE_URL/uploads/group/

BASE_URL的预期结果为http://198.**.**.**:4220/

我尝试了很多语法但没有获得计算值

尝试语法："${IP}"，${IP}，$IP

我使用 dotenv 包来访问env变量。

Answer 1

dotenv-expand是@maxbeatty回答的解决方案，以下是要遵循的步骤

步骤：

首次安装：

npm install dotenv --save
npm install dotenv-expand --save

然后更改.env文件，如：

NODE_ENV = local
PORT = 4220
IP = 192.***.**.**
BASE_URL = http://${IP}:${PORT}/

PROFILE_UPLOAD = ${BASE_URL}/uploads/profile/
POST_UPLOAD = ${BASE_URL}/uploads/discussion/
COMPANY_UPLOAD = ${BASE_URL}/uploads/company/
ITEM_UPLOAD  = ${BASE_URL}/uploads/item/
GROUP_UPLOAD  = ${BASE_URL}/uploads/group/

最后一步：

var dotenv = require('dotenv');
var dotenvExpand = require('dotenv-expand');

var myEnv = dotenv.config();
dotenvExpand(myEnv);

process.env.PROFILE_UPLOAD; // to access the .env variable

OR（缩短方式）

require('dotenv-expand')(require('dotenv').config()); // in just single line
process.env.PROFILE_UPLOAD; // to access the .env variable

Answer 2

dotenv-expand建立在dotenv之上，以解决这个特定问题

Answer 3

不幸的是dotenv无法合并变量。检查this issue以查看更多内容并找到适合您项目的解决方案。

Answer 4

如前所述，您无法在.env文件中分配变量。您可以将* _UPLOAD文件移动到config.js file并将其检入.gitignore，然后就可以了

//config.js

const BASE_URL = `http://${process.env.IP}:${process.env.PORT}/`

module.exports = {
 PROFILE_UPLOAD: BASE_URL+"uploads/profile/",
 POST_UPLOAD: BASE_URL+"uploads/discussion/",
 ....
}

带有.env文件的变量赋值

4 个答案: