package me.moocar.logbackgelf;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;
public class InternetUtils {
private static final String REGEX_IP_ADDRESS = "\\d+(\\.\\d+){3}";
private InternetUtils() {
}
/**
* Retrieves the local host's hostname. If found, the fully qualified domain name (FQDN) will be returned,
* otherwise it will fallback to the unqualified domain name. E.g prefer guerrero.moocar.me over guerrero.
*/
public static String getLocalHostName() throws SocketException, UnknownHostException {
try {
final String canonicalHostName = InetAddress.getLocalHost().getCanonicalHostName();
if (isFQDN(canonicalHostName)) {
return canonicalHostName;
} else {
return InetAddress.getLocalHost().getHostName();
}
} catch (UnknownHostException e) {
NetworkInterface networkInterface = NetworkInterface.getNetworkInterfaces().nextElement();
if (networkInterface == null)
throw e;
InetAddress ipAddress = networkInterface.getInetAddresses().nextElement();
if (ipAddress == null)
throw e;
return ipAddress.getHostAddress();
}
}
/**
* Returns true is the hostname is a Fully Qualified Domain Name (FQDN)
*/
private static boolean isFQDN(String hostname) {
return hostname.contains(".") && !hostname.matches(REGEX_IP_ADDRESS);
}
/**
* Gets the Inet address for the graylog2ServerHost and gives a specialised error message if an exception is thrown
*
* @return The Inet address for graylog2ServerHost
*/
public static InetAddress getInetAddress(String hostName) {
try {
return InetAddress.getByName(hostName);
} catch (UnknownHostException e) {
throw new IllegalStateException("Unknown host: " + e.getMessage() +
". Make sure you have specified the 'graylog2ServerHost' property correctly in your logback.xml'");
}
}
}