)

On Wed, Jul 23, 2014 at 2:55 PM, m.roth@5-cent.us wrote:

Mauricio Tavares wrote:

...

On Wed, Jul 23, 2014 at 2:01 PM, m.roth@5-cent.us wrote:

...

I've a 7 box (actually, it's RHEL, but the general list there is moribund), and I'm trying to configure it "correctly" so that it gets its hostname from the DHCP server. All I've found so far is a script to use from hooks of some kind. *Surely* there's just a configuration file option somewhere....

  Best I found using network manager is writing a script,

dhclient-exit-hooks.d/hostname (http://askubuntu.com/questions/104918/how-to-get-hostname-from-dhcp-server). There is also a way to do that using systemd-networkd; I am not very proud to say I know how to do so though.

I've been digging, and found something a) confusing and b) disturbing. But first, *does* NM use any of the /etc/sysconfig/network-scripts *other* than the ifcfg-<interface>? Specifically, does it use ifup, ifdown, and esp. ifup-post?

Here's the reason: in ifup-post is the following code: # don't set hostname on ppp/slip connections if [ "$2" = "boot" -a \ "${DEVICE}" != lo -a \ "${DEVICETYPE}" != "ppp" -a \ "${DEVICETYPE}" != "slip" ]; then if need_hostname; then IPADDR=$(LANG=C ip -o -4 addr ls dev ${DEVICE} | awk '{ print $4 ; exit }') eval $(/bin/ipcalc --silent --hostname ${IPADDR} ; echo "status=$?") if [ "$status" = "0" ]; then set_hostname $HOSTNAME fi fi fi

Now, that function, need_hostname, is in network-functions, and reads: need_hostname () { CHECK_HOSTNAME=$(hostname) if [ "$CHECK_HOSTNAME" = "(none)" -o "$CHECK_HOSTNAME" = "localhost" -o \ "$CHECK_HOSTNAME" = "localhost.localdomain" ]; then return 0 else return 1 fi }

So it *should* be setting it... if it's called.

My experience with NM is from ubuntu, over there if you configure an interface in the /etc/network/interfaces file (their equivalent of /etc/sysconfig/network-scripts , it *should* not try to fondle that interface any longer. That said, the network-scripts do have a

NM_CONTROLLED=no

option, so NM must at least check for that. I have a feeling if you set that to yes, it will ignore the rest of the file and do its own thing.

There is also a /etc/NetworkManager/ directory which seems to imply that NM does a lot of things on its own and ignore the old network config files. https://bugzilla.gnome.org/show_bug.cgi?id=667874 and the picture in http://serverfault.com/questions/429014/what-is-the-relation-between-network... seem to confirm that.

    mark

---

CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos