How to debug ParameterNotFoundException in Symfony2 - symfony

Question

I'm getting the following error after following and adapting this
ParameterNotFoundException: You have requested a non-existent parameter "mynamespace_admin.amazon_s3.aws_key". Did you mean this: "mynamespace_admin.amazon_s3.class"?
In config.yml I have:
mynamespace_admin:
amazon_s3:
aws_key: %amazon_aws_key%
aws_secret_key: %amazon_aws_secret_key%
base_url: %amazon_s3_base_url%
And in my parameters.yml I have:
amazon_aws_key: ###
amazon_aws_secret_key: ###
amazon_s3_base_url: ###
amazon_s3_bucket_name: ###
And in services.yml:
parameters:
mynamespace_admin.amazon_s3.class: AmazonS3
mynamespace_admin.image_uploader.class: mynamespace\Bundle\AdminBundle\Uploader\ImageUploader
mynamespace_admin:
amazon_s3:
class: %mynamespace_admin.amazon_s3.class%
arguments:
- "%mynamespace_admin.amazon_s3.aws_key%"
- "%mynamespace_admin.amazon_s3.aws_secret_key%"
image_uploader:
class: mynamespace_admin.image_uploader.class%
arguments: [image_storage_filesystem]
Can anyone see what I have configured incorrectly or advise on how to debug this? Why can't mynamespace_admin.amazon_s3.aws_key be read from config.yml?

Answer 1

If things are not listed under the parameters key in the service configuration, it is not assumed it is a parameter.
In all other cases (except from the services key), it is assumed that it is the configuration for an extension. In this case, the extension called mynamespace_admin. That extension should parse the settings and maybe put them in the container as parameters, or use them to decide which files to include, etc.
Assume you have a correct Configuration class for the config you have given, your extension will look like this if you want to use the config as parameters:
// ...
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\Config\FileLocator;
use Symfony\Component\HttpKernel\DependencyInjection\Extension;
use Symfony\Component\DependencyInjection\Loader;
class MynamespaceAdminExtension extends Extension
{
/**
* {#inheritDoc}
*/
public function load(array $configs, ContainerBuilder $container)
{
$configuration = new Configuration();
$config = $this->processConfiguration($configuration, $configs);
// ... do some other stuff, like loading service definition files
// loop through the processed config and save them as parameters
foreach ($config['amazon_s3'] as $name => $value) {
$container->setParameter('mynamespace_admin.amazon_s3.'.$name, $value);
}
}
}