Network-manager problems on RPI 3


#1

Hello,

we try to configure our network connections on a RPI with Core 18 via network-manager. The network setup on RPI with network-manager just does not work as we would expect it. Let me post our steps and the problems we face:

  • We use a plain Ubuntu Core 18 RPI 3 image

  • On startup we use an ethernet connection to set up the device. Everything is working out fine and I can access the internet, install snaps, …

  • We install the network manager and configure our wifi:

    snap install network-manager
    nmcli r wifi on
    nmcli d wifi list
    nmcli d wifi connect my_wifi password
    sudo reboot

  • We also enable the ethernet connection via network-manager:

    snap set network-manager ethernet.enable=true
    sudo reboot

  • Now our wifi connection is established and everything looks fine in the network-manager:

    DEVICE TYPE STATE CONNECTION
    eth0 ethernet connected Wired connection 1
    wlan0 wifi connected FRITZ!Box 7312

Now the following problems occur:

  • During device startup it is shown

    Ubuntu Core 18 on (tty1)

    You cannot log in until the system has an IP address. (Is there supposed to be a DHCP server running on your network?)

    (eventually this vanishes and the default screen is shown)

  • If I want to access a website (e.g. via curl), I get the following:

    curl: (6) Could not resolve host: www.google.de

  • The device is still accessible via ssh but it seems that I am just not able to access the internet from the device.

Do you have any ideas? Thanks!

I have just added some more background information which might be helpful:

Device information:

core               16-2.36.1          5898  stable    canonical✓  core
core18             18                 445   stable    canonical✓  base
network-manager    1.2.2-17           315   stable    canonical✓  -
pi                 18-0.1             2     18-pi3    canonical✓  gadget
pi-kernel          4.15.0-1028.30     15    18-pi3    canonical✓  kernel
snapd              2.36               1399  stable    canonical✓  snapd

/snap/network-manager/current/etc/NetworkManager/NetworkManager.conf

    [main]
    plugins=ifupdown,keyfile
    # Not using dnsmasq yet. Need to get it properly integrated
    # into the snap or reuse the one shiped with the OS snap.
    # rc-manager=resolvconf directs NM to use the resolvconf
    # binary to update resolv.conf, which is necessary as there's
    # more than one network management stack on core devices.
    dns=default
    rc-manager=resolvconf

    # Use internal DHCP stack which is based on the systemd
    # implementation and is enough for our purpose until we
    # need something more complex.
    dhcp=internal

    [ifupdown]
    managed=false

/etc/netplan/00-default-nm-renderer.yaml:

 network:
   renderer: NetworkManager

/etc/netplan/00-snapd-config.yaml:

# This is the network config written by 'console_conf'
network:
  ethernets:
    eth0:
      addresses: []
      dhcp4: true
  version: 2
  wifis:
    wlan0:
      access-points:
      addresses: []
      dhcp4: true

#2

Just tried the same thing with a core 16 image and it is working now!
Any ideas what the problem with core 18 might be?


#3

It is likely the line ‘rc-manager=resolvconf’ in the config which causes the problem, as resolvconf has been deprecated in Ubuntu 18.04 on which Core 18 is based. The NetworkManager snap will need updating to be able to integrate with the systemd-resolved process which is now used to manage DNS.


#4

I’m told that the 1.10 track of the network-manager snap should be compatible with core18. Note that it’s currently only at ‘beta’ on that track.

snap refresh --channel 1.10/beta network-manager to give it a try.


#5

Thanks for your quick reply. I’ll try it out and let you know.