get resolved parameters in a bundle extension class - symfony

Question

I'm writing a Symfony bundle and I need to setup a service definition in my Extension class depending on the value of a configuration parameter.
An it works fine, as long as you don't try to use any expressions in the parameter value.
My extension class looks like this:
class MyBundleExtension extends Extension
{
/**
* {#inheritdoc}
*/
public function load(array $configs, ContainerBuilder $container)
{
$configuration = $this->getConfiguration($configs, $container);
$config = $this->processConfiguration($configuration, $configs);
dd($config['custom_param']);
}
...
}
In my application, I set the parameter like this:
.env.local:
MY_BUNDLE_CUSTOM_PARAM=blah
config.yaml:
parameters:
my_bundle_custom_param: '%env(MY_BUNDLE_CUSTOM_PARAM)%'
my_bundle:
custom_param: '%my_bundle_custom_param%'
The problem is, that in the Extension class, this parameter is not yet resolved, so dd() shows this:
"env_de85db6c4d65707d_MY_BUNDLE_CUSTOM_PARAM_71f5c271abfed252c958c82c1e3fb8dc"
instead of the expected blah.
Is there any way to get the resolved value of the parameter in the Extension class?

Answer 1

You gave the correct answer in your comment:
/**
* #throws \Exception
*/
public function load(array $configs, ContainerBuilder $container): void
{
$configuration = new Configuration();
$config = $this->processConfiguration($configuration, $configs);
$resolve = $container->resolveEnvPlaceholders($config, true);
$config['upload_path'] = \str_replace($_SERVER['DOCUMENT_ROOT'], '', $resolve['upload_directory']);
$container->setParameter("mybundle", $config);