Extract Kerberos TGT from UGI

July 9, 2022

What's inside this article ⌄

Extract kerberos TGT from UGI
Hadoop UserGroupInformation TGT
Get Kerberos ticket from UGI
UGI kerberos credentials extract

If you need to:

view lifetime of your Kerberos ticket in Hadoop’s UserGroupInformation
see Kerberos ticket expiration date in UserGroupInformation (and do other things)

You need to extract Kerberos TGT from UserGroupInformation.

Here is how we can do it:

public KerberosTicket extractTgtFromUGI(UserGroupInformation ugi) {
    Method method = null;
    try {
        method = ugi.getClass().getDeclaredMethod("getTGT");
        method.setAccessible(true);
        KerberosTicket tgt = (KerberosTicket) method.invoke(ugi);
        log.info("Kerberos ticket info. startTime={}, endTime={}, renewTill={}", tgt.getStartTime(), tgt.getEndTime(), tgt.getRenewTill());
        return tgt;
    } catch (NoSuchMethodException | InvocationTargetException | IllegalAccessException ex) {
        throw new RuntimeException(ex);
    }
}