HTTP 500 on Docker due to missing `aria` binary

[TristanCottam]

On Nextcloud 27.1.3, NCDownloader returns HTTP status code 500 due to the aria2 binary being missing, presumably because of aria2c having been merged into aria2 (confirmation needed).

A temporary workaround is to apt update && apt upgrade && apt install aria2 inside the Docker container.

Error message:

Symfony\Component\Process\Exception\ProcessSignaledException: The process has been signaled with signal "11".

    /var/www/html/custom_apps/maps/vendor/symfony/process/Process.php - line 249:
    Symfony\Component\Process\Process->wait()

    /var/www/html/custom_apps/maps/vendor/symfony/process/Process.php - line 266:
    Symfony\Component\Process\Process->run(null, [])

    /var/www/html/custom_apps/ncdownloader/lib/Aria2/Aria2.php - line 382:
    Symfony\Component\Process\Process->mustRun()

    /var/www/html/custom_apps/ncdownloader/lib/Controller/MainController.php - line 104:
    OCA\NCDownloader\Aria2\Aria2->start()

    /var/www/html/custom_apps/ncdownloader/lib/Controller/MainController.php - line 69:
    OCA\NCDownloader\Controller\MainController->buildParams()

    /var/www/html/lib/private/AppFramework/Http/Dispatcher.php - line 230:
    OCA\NCDownloader\Controller\MainController->Index()

    /var/www/html/lib/private/AppFramework/Http/Dispatcher.php - line 137:
    OC\AppFramework\Http\Dispatcher->executeController([ "OCA\\NCDo ... "], "Index")

    /var/www/html/lib/private/AppFramework/App.php - line 183:
    OC\AppFramework\Http\Dispatcher->dispatch([ "OCA\\NCDo ... "], "Index")

    /var/www/html/lib/private/Route/Router.php - line 315:
    OC\AppFramework\App::main("OCA\\NCDown ... r", "Index", [ "OC\\AppFr ... "], [ "ncdownloader.Main.Index"])

    /var/www/html/lib/base.php - line 1068:
    OC\Route\Router->match("/apps/ncdownloader/")

    /var/www/html/index.php - line 36:
    OC::handleRequest()