[UC20][NETPLAN] Add net plan configuration to gadget.yaml but still get default configuration in system

[ChunAnWu]

we added the configuration below to gadget.yaml

###
    system:
      network:
        netplan:
          network:
            version: 2
            ethernets:
              en1:
                match:
                  driver: imx-dwmac
                addresses:
                  - 192.168.0.200/24
                set-name: en1
              en2:
                match:
                  driver: fec
                dhcp4: true
                dhcp6: true
                set-name: en2
              all-lan:
                match:
                  name: "lan*"
                dhcp4: true
                dhcp6: true
              all-eth:
                match:
                  name: "eth*"
                dhcp4: true
                dhcp6: true
###

but what we got in system by command "snap get -d system" is configuration below
looks like it append our configuration not override.

###
        "system": {
                "hostname": "ubuntu",
                "network": {
                        "netplan": {
                                "network": {
                                        "ethernets": {
                                                "all-en": {
                                                        "dhcp4": true,
                                                        "match": {
                                                                "name": "en*"
                                                        }
                                                },
                                                "all-eth": {
                                                        "dhcp4": true,
                                                        "dhcp6": true,
                                                        "match": {
                                                                "name": "eth*"
                                                        }
                                                },
                                                "all-lan": {
                                                        "dhcp4": true,
                                                        "dhcp6": true,
                                                        "match": {
                                                                "name": "lan*"
                                                        }
                                                },
                                                "en1": {
                                                        "addresses": [
                                                                "192.168.0.200/24"
                                                        ],
                                                        "match": {
                                                                "driver": "imx-dwmac"
                                                        },
                                                        "set-name": "en1"
                                                },
                                                "en2": {
                                                        "dhcp4": true,
                                                        "dhcp6": true,
                                                        "match": {
                                                                "driver": "fec"
                                                        },
                                                        "set-name": "en2"
                                                }
                                        },
                                        "version": 2
                                }
                        }
                },
###

[Michael Vogt (mvo)]

Yeah, this is a bug/misfeature. The easiest workaround might be:
"""
    system:
      network:
        netplan:
          network:
            version: 2
            ethernets:
              all-en: null
...
"""

[Alfonso Sanchez-Beato (alfonsosanchezbeato)]

Setting the configuration from cloud.conf from the gadget could be an option to workaround the issue while this get fixed, as snap pack seems to not be very happy about the null entry in all-en.

[Alfonso Sanchez-Beato (alfonsosanchezbeato)]

This seems to be caused by netplan not cleaning up config as expected (by setting network=null):

test@ubuntu:~$ sudo busctl call io.netplan.Netplan /io/netplan/Netplan/config/MIL071 io.netplan.Netplan.Config Set ss 'network=null' "00-snapd-defaults"
b true
test@ubuntu:~$ sudo busctl call io.netplan.Netplan /io/netplan/Netplan/config/MIL071 io.netplan.Netplan.Config Get
s "network:\n version: 2\n ethernets:\n all-en:\n match:\n name: \"en*\"\n dhcp4: true\n all-eth:\n match:\n name: \"eth*\"\n dhcp4: true\n"

[Alfonso Sanchez-Beato (alfonsosanchezbeato)]

There was some misunderstanding on how to use the dbus interface.

https://github.com/snapcore/snapd/pull/12961 has been proposed with a fix.