Documentation

This is the main class that sends a DNS query to your DNS server and is used internally by the Resolver for the actual message transport.

For more advanced usages one can utilize this class directly. The following example looks up the IPv6 address for igor.io.

$executor = new UdpTransportExecutor('8.8.8.8:53');

$executor->query(
    new Query($name, Message::TYPE_AAAA, Message::CLASS_IN)
)->then(function (Message $message) {
    foreach ($message->answers as $answer) {
        echo 'IPv6: ' . $answer->data . PHP_EOL;
    }
}, 'printf');

See also the fourth example.

Note that this executor does not implement a timeout, so you will very likely want to use this in combination with a TimeoutExecutor like this:

$executor = new TimeoutExecutor(
    new UdpTransportExecutor($nameserver),
    3.0
);

Also note that this executor uses an unreliable UDP transport and that it does not implement any retry logic, so you will likely want to use this in combination with a RetryExecutor like this:

$executor = new RetryExecutor(
    new TimeoutExecutor(
        new UdpTransportExecutor($nameserver),
        3.0
    )
);

Note that this executor is entirely async and as such allows you to execute any number of queries concurrently. You should probably limit the number of concurrent queries in your application or you're very likely going to face rate limitations and bans on the resolver end. For many common applications, you may want to avoid sending the same query multiple times when the first one is still pending, so you will likely want to use this in combination with a CoopExecutor like this:

$executor = new CoopExecutor(
    new RetryExecutor(
        new TimeoutExecutor(
            new UdpTransportExecutor($nameserver),
            3.0
        )
    )
);

Internally, this class uses PHP's UDP sockets and does not take advantage of react/datagram purely for organizational reasons to avoid a cyclic dependency between the two packages. Higher-level components should take advantage of the Datagram component instead of reimplementing this socket logic from scratch.