What steps can be taken to troubleshoot PHP network address resolution failures like "Temporary failure in name resolution"?

When encountering a "Temporary failure in name resolution" error in PHP, it typically indicates a DNS resolution issue. To troubleshoot this problem, you can try restarting the DNS resolver service, checking the DNS configuration, or using a different DNS server.

// Example PHP code snippet to troubleshoot DNS resolution issues
// Restart the DNS resolver service
exec('sudo service systemd-resolved restart');

// Check the DNS configuration
$dns = file_get_contents('/etc/resolv.conf');
echo $dns;

// Use a different DNS server
$dns_server = '8.8.8.8'; // Google's DNS server
echo gethostbyname('example.com', $dns_server);