节点process.env.VARIABLE_NAME返回未定义 [英] Node process.env.VARIABLE_NAME returning undefined

问题描述

我在Mac上使用环境变量来存储一些敏感的凭据，并尝试通过Node访问它们.我使用

I'm using environment variables on my mac to store some sensitive credentials, and trying to access them through Node. I added them into my environment profile with

export VARIABLE_NAME=mySensitiveInfo

当我使用echo $VARIABLE_NAME时，会收到正确的输出(我的敏感信息).

When I use echo $VARIABLE_NAME I receive the correct output (my sensitive info).

但是，当我尝试使用process.env.VARIABLE_NAME访问Node中的同一变量并尝试在控制台上将其打印出来时，却出现了未定义的情况.

However, when I am trying to access this same variable in Node with process.env.VARIABLE_NAME and try to print it out on the console, I get an undefined.

其他环境变量似乎还可以.例如，当我console.log(process.env.FACEBOOK_CALLBACK_URL)时，它会将正确的值输出到我的控制台.我几天前添加了 FACEBOOK_CALLBACK_URL .

Other environment variables appear to be okay though. For example, when I console.log(process.env.FACEBOOK_CALLBACK_URL), it prints the correct value to my console. I added FACEBOOK_CALLBACK_URL a few days ago.

我是否必须重新启动计算机?在Node中环境变量变得可用之前需要花费一些时间吗?我在SO上看到的最接近的答案是这篇文章 ，但没人能弄清楚为什么会这样.

Do I have to restart my machine or something? Does it take a certain time before environment variables become available in Node? The closest answer I've seen on SO is this post, but nobody was able to figure out why it was happening.

推荐答案

process.env.VARIABLE_NAME返回undefined，因为Node.js执行环境尚不知道新添加的VARIABLE_NAME.要解决此问题，需要重新启动Node.js执行环境(例如IDE).

process.env.VARIABLE_NAME returns undefined because the Node.js execution environment does not know the newly added VARIABLE_NAME yet. To fix the issue, the Node.js execution environment (e.g. IDE) need to restart.

以下步骤可用于重现此问题:

The following steps can be used to reproduce this issue:

1. 打开IDE(例如WebStorm)并编写一个简单的Node.js程序:console.log(process.env.VARIABLE_NAME).由于尚未定义VARIABLE_NAME，它将按预期打印undefined.保持IDE运行，不要关闭它.
2. 打开环境配置文件(例如.bash_profile)并在其中添加export VARIABLE_NAME=mySensitiveInfo.
3. 打开系统控制台并运行source .bash_profile，以便执行上述export语句.从现在开始，只要打开系统控制台，就会存在VARIABLE_NAME环境变量.
4. 在系统控制台中，在步骤1中执行Node.js程序，它将显示mySensitiveInfo.
5. 切换到IDE并执行Node.js程序，它将显示undefined.
6. 重新启动IDE并执行Node.js程序，这一次，它将打印mySensitiveInfo

1. Open IDE such as WebStorm and write a simple Node.js program: console.log(process.env.VARIABLE_NAME). It will print undefined as expected, as VARIABLE_NAME is not defined yet. Keep the IDE running, don't close it.
2. Open environment profile such as .bash_profile and add export VARIABLE_NAME=mySensitiveInfo in it.
3. Open system console and run source .bash_profile, so that the above export statement will be executed. From now on, whenever system console is opened, VARIABLE_NAME environment variable exists.
4. In system console, execute the Node.js program in step 1, it will print mySensitiveInfo.
5. Switch to IDE and execute Node.js program, it will print undefined.
6. Restart the IDE and execute Node.js program, this time, it will print mySensitiveInfo

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