Here is a PHP code snippet that constructs and executes the given Docker run command using PHP's shell_exec function. It assumes that the $contname variable is defined in PHP.

<?php

// Define the container name
$contname = 'navidrome_container'; // You can change this value dynamically

// Build the command
$command = <<<EOD
docker run -d \\
   --name {$contname} \\
   --restart=unless-stopped \\
   --user $(id -u):$(id -g) \\
   -v /opt/navidrome/{$contname}/music:/music \\
   -v /opt/navidrome/{$contname}/data:/data \\
   -e ND_LOGLEVEL=info \\
   deluan/navidrome:latest
EOD;

// Execute the command
$output = shell_exec($command);

// Output the result
echo "<pre>$output</pre>";
?>

⚠️ Important Notes:

Permissions: Make sure the PHP script is run by a user who has permission to execute Docker commands (e.g., part of the docker group).
Security: Never pass unsanitized user input directly into shell commands — that opens up shell injection vulnerabilities.
Web server context: If you're running this via a web browser and Apache/Nginx, ensure the web server user (e.g., www-data) can access Docker.

Let me know if you'd like to parameterize it more or run it in the background safely!