Client machines can't find KDC few hours after deployment

[asheplyakov]

$ kinit Administrator@DOMAIN.ALT
kinit: Cannot find KDC for realm "DOMAIN.ALT" while getting initial credentials

It looks like something (NetworkManager?) inserts nameserver 8.8.8.8 entry into /etc/resolv.conf, thus SRV lookups fail:

$ host -t SRV _kerberos._udp.DOMAIN.ALT
Host _kerberos._udp.DOMAIN.ALT not found: 3(NXDOMAIN)
$ host -t SRV _kerberos._tcp.DOMAIN.ALT
Host _kerberos._tcp.DOMAIN.ALT not found: 3(NXDOMAIN)

$ cat /etc/resolv.conf
# Generated by resolvconf
# Do not edit manually, use
# /etc/net/ifaces//resolv.conf instead.
domain domain.alt
nameserver 8.8.8.8
nameserver 10.64.6.1

$ nmcli
eth0: connected to System eth0
"Red Hat Virtio network device"
ethernet (virtio_net), 2A:1E:D2:74:DC:1B, hw, mtu 1500
ip4 default
inet4 10.64.86.100/24

eth1: unmanaged
"Red Hat Virtio network device"
ethernet (virtio_net), 7E:86:84:48:D5:F1, hw, mtu 1500

lo: unmanaged
"lo"
loopback (unknown), 00:00:00:00:00:00, sw, mtu 65536

DNS configuration:
servers: 8.8.8.8
interface: eth0

Use "nmcli device show" to get complete information about known devices and
"nmcli connection show" to get an overview on active connection profiles.

Consult nmcli(1) and nmcli-examples(5) manual pages for complete usage details.

[omgbebebe]

#5 maybe fix this, but it need testing. For example, when VM is resume from suspend this PR sometimes did not helps and recolv.conf containd servers from DHCP client.