Netplan

netplan generates duplicate dns

Bug #2007682 reported by Tommy on 2023-02-17

This bug affects 1 person

Affects		Status	Importance	Assigned to	Milestone
	Netplan	Fix Released	Low	Unassigned

Bug Description

Hello,
I have a server with Ubuntu 22.04LTS
Netplan version: netplan.io 0.104-0ubuntu2

When bonds section upper than ethernets section I see duplicate bonds.ifname.nameservers.addresses and bonds.ifname.nameservers.search:

# netplan get
network:
  version: 2
  renderer: networkd
  ethernets:
    ens3f0:
      match:
        macaddress: "some-mac"
      dhcp4: false
      set-name: "ens3f0"
    ens2f0:
      match:
        macaddress: "some-mac"
      dhcp4: false
      set-name: "ens2f0"
  bonds:
    aggi:
      addresses:
      - "10.17.0.73/26"
      nameservers:
        addresses:
        - 8.8.8.8
        - 8.8.4.4
        - 8.8.8.8
        - 8.8.4.4
        search:
        - example.com
        - example.com
      dhcp4: false
      interfaces:
      - ens2f0
      - ens3f0
      parameters:
        mode: "802.3ad"
        mii-monitor-interval: "100"
        up-delay: "200"
        down-delay: "200"
        lacp-rate: "slow"
        transmit-hash-policy: "layer3+4"
      routes:
      - to: "default"
        via: "10.17.0.67"

But when I swap sections everything is fine:
# netplan get
network:
  version: 2
  renderer: networkd
  ethernets:
    ens3f0:
      match:
        macaddress: "some-mac"
      dhcp4: false
      set-name: "ens3f0"
    ens2f0:
      match:
        macaddress: "some-mac"
      dhcp4: false
      set-name: "ens2f0"
  bonds:
    aggi:
      addresses:
      - "10.17.0.73/26"
      nameservers:
        addresses:
        - 8.8.8.8
        - 8.8.4.4
        search:
        - example.com
      dhcp4: false
      interfaces:
      - ens2f0
      - ens3f0
      parameters:
        mode: "802.3ad"
        mii-monitor-interval: "100"
        up-delay: "200"
        down-delay: "200"
        lacp-rate: "slow"
        transmit-hash-policy: "layer3+4"
      routes:
      - to: "default"
        via: "10.17.0.67"

Tags:

Revision history for this message

Danilo Egea Gondolfo (danilogondolfo) wrote on 2023-02-20 (last edit on 2023-02-20):

Hi, thanks for your bug report.

I can confirm that the problem still exists on netplan.io 0.106.

Here is a simpler reproducer:

$ cat /tmp/fakeroot/etc/netplan/90-configs.yaml
network:
  bonds:
    aggi:
      nameservers:
        addresses:
        - 8.8.8.8
        search:
        - example.com
      interfaces:
      - ens3f0
  ethernets:
    ens3f0: {}

$ netplan get --root-dir /tmp/fakeroot/
network:
  version: 2
  ethernets:
    ens3f0: {}
  bonds:
    aggi:
      nameservers:
        addresses:
        - 8.8.8.8
        - 8.8.8.8
        search:
        - example.com
        - example.com
      interfaces:
      - ens3f0

And indeed the duplication doesn't happen if "ethernets" is defined before "bonds".

Lukas Märdian (slyon) on 2023-02-20

Changed in netplan:
status:	New → Triaged
importance:	Undecided → Low

Revision history for this message

Danilo Egea Gondolfo (danilogondolfo) wrote on 2023-02-24:

It also generates duplicated entries so the problem is not only with the "netplan get" command:

$ cat /tmp/fakeroot/etc/netplan/90-config.yaml
network:
  bonds:
    aggi:
      nameservers:
        addresses:
        - 8.8.8.8
        search:
        - example.com
      interfaces:
      - ens3f0
  ethernets:
    ens3f0: {}

$ cat /tmp/fakeroot/run/systemd/network/10-netplan-aggi.network
[Match]
Name=aggi

[Network]
LinkLocalAddressing=ipv6
DNS=8.8.8.8
DNS=8.8.8.8
Domains=example.com example.com
ConfigureWithoutCarrier=yes

Revision history for this message

Danilo Egea Gondolfo (danilogondolfo) wrote on 2023-02-24:

The problem happens when the parser needs a second pass to find all the interfaces. It doesn't check if the values are already in their lists.

The problem is not limited to the DNS entries.

Here is another example:

network:
  bonds:
    aggi:
      routing-policy:
        - table: 1
          from: 1.2.3.4
      nameservers:
        addresses:
        - 8.8.8.8
        search:
        - example.com
      interfaces:
      - ens3f0
  ethernets:
    ens3f0: {}

The .netdev file will look like this:

[Match]
Name=aggi

[Network]
LinkLocalAddressing=ipv6
DNS=8.8.8.8
DNS=8.8.8.8
Domains=example.com example.com
ConfigureWithoutCarrier=yes

[RoutingPolicyRule]
From=1.2.3.4
Table=1

Danilo Egea Gondolfo (danilogondolfo) on 2023-02-27

tags:

added: fr-3537

Revision history for this message

Danilo Egea Gondolfo (danilogondolfo) wrote on 2023-02-28:

Another instance of duplication:

network:
  bridges:
    br0:
      openvswitch:
        protocols:
          - OpenFlow10
          - OpenFlow11
          - OpenFlow12
        controller:
          addresses:
            - tcp:127.0.0.1:6653
            - tcp:127.0.0.2:6653
      interfaces:
        - nic1
  ethernets:
    nic1: {}

$ tail -n 4 /tmp/fakeroot/run/systemd/system/netplan-ovs-br0.service
ExecStart=/usr/bin/ovs-vsctl set Bridge br0 protocols=OpenFlow10,OpenFlow11,OpenFlow12,OpenFlow10,OpenFlow11,OpenFlow12
ExecStart=/usr/bin/ovs-vsctl set Bridge br0 external-ids:netplan/protocols=OpenFlow10,OpenFlow11,OpenFlow12,OpenFlow10,OpenFlow11,OpenFlow12
ExecStart=/usr/bin/ovs-vsctl set-controller br0 tcp:127.0.0.1:6653 tcp:127.0.0.2:6653 tcp:127.0.0.1:6653 tcp:127.0.0.2:6653
ExecStart=/usr/bin/ovs-vsctl set Bridge br0 external-ids:netplan/global/set-controller=tcp:127.0.0.1:6653,tcp:127.0.0.2:6653,tcp:127.0.0.1:6653,tcp:127.0.0.2:6653