使用PHP脚本获取Heroku环境变量

Question

I can't access my Heroku environment variables when I run a PHP script. On the picture below you can see that I have variable TEST_VAR.

The code snippet below should output this variable, I get nothing instead:

$url = getenv('TEST_VAR');
echo $url;

I tried this and got 'Error!', so getenv('TEST_VAR') is false:

if (getenv('TEST_VAR')) {
    $url = getenv('TEST_VAR');
    echo $url;
} else {
    die('Error!');
}

In this picture you can see the output of both snippets (empty string and Error!).

Answer 1

It looks like you're running that code on your local command line. heroku config:set sets environment variables for your app on Heroku. It doesn't do anything to your local environment.

To use environment variables locally you must set them another way. You could do it manually, using whatever tools your operating system provides, but the Heroku CLI also provides a heroku local command that conveniently reads environment variables from a file called .env and populates them for you.

Simply create an .env file containing your variables, e.g.

TEST_VAR=hello_world

and then run your code via heroku local. By default this will run your web process as defined in your Procfile. If you have already set up variables using heroku config:set you can copy them to your .env file:

heroku config:get TEST_VAR >> .env

Note that the .env file should not be committed to your repository. It's meant for local use only. On Heroku, you should continue to set config vars using heroku config:set.