directory needs to exist before being used as sf2 container parameter

Question

What is the best practice for setting container parameters that need to be properly setup, e.g. I have a parameter called 'feed_filesystem_cache_path' (string of '%kernel.cache_dir%' + /directory location) which I am injecting into some service classes.

I see myself checking on existance in those classes and would like to know if there's a better way to do that.

I've tried to alter my bundle's container extension, but seems like the parameters aren't resolved by then; I'm still getting '%kernel.cache_dir%/feeds' instead of a fully qualified/compiled path.

Trying in Bundle class, in the build method (just after parent::build($container) isn't helping me much either, at that point the containe only has "kernel" services and parameters.

Answer 1

Converting my comment into an answer to have a decent reply to this question

A reasonnable way to do this, is to create a Cache Warmer
To do so, you need to create a new service, and tag it with kernel.cache_warmer

services.yml

services:
    acme_foo.my_warmer:
        class: Acme\FooBundle\CacheWarmer
        arguments:
            - @filesystem
        tags:
            - name: kernel.cache_warmer
            - priority: 0

A cache warmer must implement CacheWarmerInterface.

namespace Acme\FooBundle;

use Symfony\Component\Filesystem\Filesystem;
use Symfony\Component\HttpKernel\CacheWarmer\CacheWarmerInterface

class CacheWarmer implements CacheWarmerInterface
{
    protected $filesystem;

    public function __construct(Filesystem $filesystem)
    {
        $this->filesystem = $filesystem;
    }

    /**
     * {@inheritDoc}
     */
    public function warmUp($cacheDir)
    {
        $real = sprintf("%s/feeds", $cacheDir);

        $this->filesystem->mkdir($real);
    }

    /**
     * {@inheritDoc}
     */
    public function isOptional()
    {
        return true;
    }
}

With this component, the directory /feeds will be created when you execute cache:clear (without --no-warmup) or cache:warmup command.

It worth mentionning that you may check in your application that the directory exists, to prevent any fatal error in case of your cache haven't been warmed up

$filename = "/cache/dir/feeds/file";

if (!is_dir(dirname($filename))) {
    mkdir(dirname($filename));
}

Answer 2

As Touki said, a cache warmer might do the trick.