horizon: Configuring the queue to be processed by a separate server to the main application server adds the job to the wrong redis store

• Horizon Version: 5.7.17
• Laravel Version: 8.76.2
• PHP Version: 7.4.24
• Redis Driver & Version: predis 1.1.9
• Database Driver & Version: MySQL 5.7.36

Description:

If you configure a custom redis connection for an external server in config/database.php and then set that as the redis queue connection in config/queue.php, queued jobs are added to the local redis store on the application server instead of being pushed to the external server redis store that is configured for use.

Steps To Reproduce:

• Install a fresh laravel application and horizon.
• Add a new entry to the redis array in config/database.php and add the environment variables for the external redis server

'queue' => [
    'url' => env('REDIS_QUEUE_URL'),
    'host' => env('REDIS_QUEUE_HOST', '127.0.0.1'),
    'password' => env('REDIS_QUEUE_PASSWORD', null),
    'port' => env('REDIS_QUEUE_PORT', '6379'),
    'database' => env('REDIS_QUEUE_DB', '0'),
]

• Update the connection value to ‘queue’ for the redis entry in config/queue.php

'redis' => [
    'driver' => 'redis',
    'connection' => 'queue',
    'queue' => env('REDIS_QUEUE', 'default'),
    'retry_after' => 90,
    'block_for' => null,
    'after_commit' => false,
]

• Create a job and dispatch it
• The job will be a pending job on the server the job was dispatched from and not be in the redis store on the external server.
• https://github.com/Really-Simple-Systems/horizon-bug-report