NetworkUpdate: Operation not supported: can't update 'ip' section of network 'default' about go-libvirt HOT 5 CLOSED

Hmm. Going with your suggestion, I "widened" the net... I tried setting command, section, and flags to 4. Flags wouldn't allow it (actually gave me a flags related error).

But...

	cmd := uint32(4)
	section := uint32(4)
	fmt.Printf("NetworkUpdate(%d, %d, -1, %s, %d)\n", cmd, section, networkDhcpXML, 0)
	err = client.NetworkUpdate(net, cmd, section, -1, networkDhcpXML, 0)

Gave me:

NetworkUpdate(4, 4, -1, <host name='vm-8029d8c8-ee6c-45b9-6476-3ba7381c3cb5' ip='192.168.123.7'/>, 0)
Setup network DHCP

... and as proof:

$ virsh net-dumpxml default
<network>
  <name>default</name>
  <uuid>bcb85dc8-ad27-4861-9f85-692167fd79fa</uuid>
  <forward mode='nat'>
    <nat>
      <port start='1024' end='65535'/>
    </nat>
  </forward>
  <bridge name='virbr0' stp='on' delay='0'/>
  <mac address='52:54:00:82:d1:6e'/>
  <ip address='192.168.123.1' netmask='255.255.255.0'>
    <dhcp>
      <range start='192.168.123.2' end='192.168.123.254'/>
      <host name='vm-8029d8c8-ee6c-45b9-6476-3ba7381c3cb5' ip='192.168.123.7'/>
      <host name='totally-fake-vm' ip='192.168.123.6'/>
    </dhcp>
  </ip>
</network>

... and running it again errors out (as expected):

NetworkUpdate(4, 4, -1, <host name='vm-8029d8c8-ee6c-45b9-6476-3ba7381c3cb5' ip='192.168.123.7'/>, 0)
panic: Requested operation is not valid: there is an existing dhcp host entry in network 'default' that matches "<host mac='unknown' name='vm-8029d8c8-ee6c-45b9-6476-3ba7381c3cb5' ip='192.168.123.7'/>"

Is something cross-wired somewhere? Even in my code? Sadly, I'm not spotting anything. (But also admitting I'm a Go rookie, haven't touched C in 30 years, and utter neophyte with Libvirt! LOL)

from go-libvirt.

Thank you so much for posting this issue. We've just run into it with the terraform libvirt provider.

Seems there has been work going on upstream to improve a situation where command and section argument ordering is swapped around.

See:

• v1 fix (not merged) https://listman.redhat.com/archives/libvir-list/2021-March/msg00054.html
• v2 fix (merged) https://listman.redhat.com/archives/libvir-list/2021-March/msg00758.html

from go-libvirt.

The error you're getting seems to be coming from virNetworkDefUpdateIP in the libvirt sources. But that's not the right routine - you're trying to update the DHCP host settings, which is section "ip/dhcp/host", and is handled by virNetworkDefUpdateIPDHCPHost. You'd get this error if the section parameter passed into the NetworkUpdate call were wrong (3 instead of 4), but libvirt.NetworkSectionIpDhcpHost and NETWORK_SECTION_IP_DHCP_HOST are both 4, in the sources I'm looking at. (libvirt 4.0.0). It might be interesting to try some other values for the section parameter, and see if you get back sensible errors.

from go-libvirt.

I get the same response regardless of values (tried 1, 2, 3, 4, 5, and 500):

NetworkUpdate(3, 500, -1, <host name='vm-8029d8c8-ee6c-45b9-6476-3ba7381c3cb5' ip='192.168.123.7'/>, 0)
panic: Operation not supported: can't update 'ip' section of network 'default'

I am using Go 1.12 and modules. go.mod is:

$ cat go.mod
module ip-dhcp-host

go 1.12

require github.com/digitalocean/go-libvirt v0.0.0-20190715144809-7b622097a793

Just in case there's a specific version or something.

from go-libvirt.

My take on this is cfergeau@8108763

from go-libvirt.