Hey all, I've been trying to get my Laravel application to connect to a MariaDB database for hours now without any success. There's quite obviously something I'm missing but I'm not sure what exactly.

Here's the error I'm getting from Laravel:

PDOException in Connector.php line 55:
SQLSTATE[HY000] [2002] Connection refused

Here's my database.php:

'default' => env('DB_CONNECTION', 'mysql'),

'connections' => [

        'sqlite' => [
            'driver'   => 'sqlite',
            'database' => database_path('database.sqlite'),
            'prefix'   => '',
        ],

        'mysql' => [
            'driver'    => 'mysql',
            'host'      => env('DB_HOST', '0.0.0.0'),
            'database'  => env('DB_DATABASE', 'blog'),
            'username'  => env('DB_USERNAME', 'root'),
            'password'  => env('DB_PASSWORD', 'root'),
            'charset'   => 'utf8',
            'collation' => 'utf8_unicode_ci',
            'prefix'    => '',
            'strict'    => false,
        ],

        'pgsql' => [
            'driver'   => 'pgsql',
            'host'     => env('DB_HOST', 'localhost'),
            'database' => env('DB_DATABASE', 'forge'),
            'username' => env('DB_USERNAME', 'forge'),
            'password' => env('DB_PASSWORD', ''),
            'charset'  => 'utf8',
            'prefix'   => '',
            'schema'   => 'public',
        ],

        'sqlsrv' => [
            'driver'   => 'sqlsrv',
            'host'     => env('DB_HOST', 'localhost'),
            'database' => env('DB_DATABASE', 'forge'),
            'username' => env('DB_USERNAME', 'forge'),
            'password' => env('DB_PASSWORD', ''),
            'charset'  => 'utf8',
            'prefix'   => '',
        ],

    ],

Here's my .env from the deployed app on Dokku

export APP_DEBUG='true'
export APP_ENV='production'
export BUILDPACK_URL='https://github.com/heroku/heroku-buildpack-php'
export DATABASE_URL='mysql://mariadb:-snip-b@dokku-mariadb-blog:3306/blog'
export DB_CONNECTION='mysql'
export DB_DATABASE='blog'
export DB_HOST='0.0.0.0'
export DB_PASSWORD='root'
export DB_USERNAME='root'
export DOKKU_APP_RESTORE='1'
export DOKKU_NGINX_PORT='80'

Laravel error dump:

in Connector.php line 55
at PDO->__construct('mysql:host=0.0.0.0;dbname=blog', 'root', 'root', array('0', '2', '0', false, false)) in Connector.php line 55
at Connector->createConnection('mysql:host=0.0.0.0;dbname=blog', array('driver' => 'mysql', 'host' => '0.0.0.0', 'database' => 'blog', 'username' => 'root', 'password' => 'root', 'charset' => 'utf8', 'collation' => 'utf8_unicode_ci', 'prefix' => '', 'strict' => false, 'name' => 'mysql'), array('0', '2', '0', false, false)) in MySqlConnector.php line 24
at MySqlConnector->connect(array('driver' => 'mysql', 'host' => '0.0.0.0', 'database' => 'blog', 'username' => 'root', 'password' => 'root', 'charset' => 'utf8', 'collation' => 'utf8_unicode_ci', 'prefix' => '', 'strict' => false, 'name' => 'mysql')) in ConnectionFactory.php line 61
at ConnectionFactory->Illuminate\Database\Connectors\{closure}()
at call_user_func(object(Closure)) in Connection.php line 846
at Connection->getPdo() in Connection.php line 714
at Connection->reconnectIfMissingConnection() in Connection.php line 603
at Connection->run('select * from `posts` where `published_at` <= ? and `is_draft` = ? order by `published_at` desc limit 11 offset 0', array(object(Carbon), '0'), object(Closure)) in Connection.php line 324
at Connection->select('select * from `posts` where `published_at` <= ? and `is_draft` = ? order by `published_at` desc limit 11 offset 0', array(object(Carbon), '0'), true) in Builder.php line 1461
at Builder->runSelect() in Builder.php line 1447
at Builder->get(array('*')) in Builder.php line 503
at Builder->getModels(array('*')) in Builder.php line 237
at Builder->get(array('*')) in Builder.php line 396
at Builder->simplePaginate('10') in BlogIndexData.php line 50
at BlogIndexData->normalIndexData() in BlogIndexData.php line 36
at BlogIndexData->handle()
at call_user_func_array(array(object(BlogIndexData), 'handle'), array()) in Container.php line 507
at Container->call(array(object(BlogIndexData), 'handle')) in Dispatcher.php line 82
at Dispatcher->Illuminate\Bus\{closure}(object(BlogIndexData))
at call_user_func(object(Closure), object(BlogIndexData)) in Pipeline.php line 139
at Pipeline->Illuminate\Pipeline\{closure}(object(BlogIndexData))
at call_user_func(object(Closure), object(BlogIndexData)) in Pipeline.php line 102
at Pipeline->then(object(Closure)) in Dispatcher.php line 83
at Dispatcher->dispatchNow(object(BlogIndexData)) in Dispatcher.php line 69
at Dispatcher->dispatch(object(BlogIndexData)) in DispatchesJobs.php line 17
at Controller->dispatch(object(BlogIndexData)) in BlogController.php line 15
at BlogController->index(object(Request))
at call_user_func_array(array(object(BlogController), 'index'), array(object(Request))) in Controller.php line 76
at Controller->callAction('index', array(object(Request))) in ControllerDispatcher.php line 146
at ControllerDispatcher->call(object(BlogController), object(Route), 'index') in ControllerDispatcher.php line 94
at ControllerDispatcher->Illuminate\Routing\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 52
at Pipeline->Illuminate\Routing\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 102
at Pipeline->then(object(Closure)) in ControllerDispatcher.php line 96
at ControllerDispatcher->callWithinStack(object(BlogController), object(Route), object(Request), 'index') in ControllerDispatcher.php line 54
at ControllerDispatcher->dispatch(object(Route), object(Request), '\Voident\Http\Controllers\BlogController', 'index') in Route.php line 174
at Route->runController(object(Request)) in Route.php line 140
at Route->run(object(Request)) in Router.php line 703
at Router->Illuminate\Routing\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 52
at Pipeline->Illuminate\Routing\{closure}(object(Request)) in VerifyCsrfToken.php line 64
at VerifyCsrfToken->handle(object(Request), object(Closure))
at call_user_func_array(array(object(VerifyCsrfToken), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124
at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
at Pipeline->Illuminate\Routing\{closure}(object(Request)) in ShareErrorsFromSession.php line 49
at ShareErrorsFromSession->handle(object(Request), object(Closure))
at call_user_func_array(array(object(ShareErrorsFromSession), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124
at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
at Pipeline->Illuminate\Routing\{closure}(object(Request)) in StartSession.php line 62
at StartSession->handle(object(Request), object(Closure))
at call_user_func_array(array(object(StartSession), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124
at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
at Pipeline->Illuminate\Routing\{closure}(object(Request)) in AddQueuedCookiesToResponse.php line 37
at AddQueuedCookiesToResponse->handle(object(Request), object(Closure))
at call_user_func_array(array(object(AddQueuedCookiesToResponse), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124
at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
at Pipeline->Illuminate\Routing\{closure}(object(Request)) in EncryptCookies.php line 59
at EncryptCookies->handle(object(Request), object(Closure))
at call_user_func_array(array(object(EncryptCookies), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124
at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
at Pipeline->Illuminate\Routing\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 102
at Pipeline->then(object(Closure)) in Router.php line 705
at Router->runRouteWithinStack(object(Route), object(Request)) in Router.php line 678
at Router->dispatchToRoute(object(Request)) in Router.php line 654
at Router->dispatch(object(Request)) in Kernel.php line 246
at Kernel->Illuminate\Foundation\Http\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 52
at Pipeline->Illuminate\Routing\{closure}(object(Request)) in CheckForMaintenanceMode.php line 44
at CheckForMaintenanceMode->handle(object(Request), object(Closure))
at call_user_func_array(array(object(CheckForMaintenanceMode), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124
at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
at Pipeline->Illuminate\Routing\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 102
at Pipeline->then(object(Closure)) in Kernel.php line 132
at Kernel->sendRequestThroughRouter(object(Request)) in Kernel.php line 99
at Kernel->handle(object(Request)) in index.php line 53

Finally, here are all the commands I used to set up my app.

$ dokku apps:create app_name
$ dokku plugin:install https://github.com/dokku/dokku-mariadb.git mariadb

$ dokku mariadb:create blog
$ dokku mariadb:link blog blog
$ dokku mariadb:info blog blog
-> DSN: mysql://mariadb:-snip-@dokku-mariadb-blog:3306/blog

$ dokku config:set blog DB_CONNECTION=mysql DB_HOST=0.0.0.0 DB_DATABASE=blog DB_USERNAME=root DB_PASSWORD=root

$ dokku config:add BUILDPACK_URL=https://github.com/heroku/heroku-buildpack-php