public virtual void TestUGILoginFromKeytab()
{
UserGroupInformation.SetShouldRenewImmediatelyForTests(true);
string principal = "foo";
FilePath keytab = new FilePath(workDir, "foo.keytab");
kdc.CreatePrincipal(keytab, principal);
UserGroupInformation.LoginUserFromKeytab(principal, keytab.GetPath());
UserGroupInformation ugi = UserGroupInformation.GetLoginUser();
Assert.True("UGI should be configured to login from keytab", ugi
.IsFromKeytab());
// Verify relogin from keytab.
User user = ugi.GetSubject().GetPrincipals <User>().GetEnumerator().Next();
long firstLogin = user.GetLastLogin();
ugi.ReloginFromKeytab();
long secondLogin = user.GetLastLogin();
Assert.True("User should have been able to relogin from keytab"
, secondLogin > firstLogin);
}