[CentOS] CentOS 7, systemd, NetworkMangler, oh, my

Alice Wonder
2017-02-15T04:40:20Z

On 02/14/2017 06:49 AM, Johnny Hughes wrote:

>
> But as Linux installs become more and more complicated and it is not
> some individual machines in a rack but clouds, clusters, and containers
> with software defined networking and individual segments for specific
> applications spread out within the network, only talking to one another
> .. etc.  Well, NM will be much more important.

All due respect, when we drop KISS it is rarely a good thing.

Issue I am dealing with right now - all my VMs with linode are CentOS 7.

Three of them are nameservers, I have to run my own because some of my
sites - I use certificate authorities but do not trust them, DNSSEC with
DANE is a must, and with DNSSEC the only way to make sure I'm the only
one with access to the private signing key is to manage the zone files
myself.

One of the VMs (in London data center) was recently migrated to a
different machine, I think because of a bad fan in the server.

NSD never properly came up. After investigation, it is because the IPv6
address changed.

Trying to figure out why the IPv6 address changed has been a nightmare.

Linode support suspects the reason is because the VM is using slaac
private to request the IP address instead of slaac hwaddr - and
suggested that I change the /etc/dhcpcd.conf file.

Well CentOS 7 doesn't use that, and trying to figure out where in the
mess of /etc/sysconfig/network-scripts the problem is occurring has
caused me much frustration.

Why the bleep can't stuff like this be simple KISS with simple key=value
configuration files?

So for now, that particular nameserver is only IPv4 until I figure it
out, and modifying the network scripts to try and figure out how to fix
it raises my blood pressure because if a modification causes the IPv4
not to work, recovering becomes a real PITA.