Network configuration doesn't survive reboots after bionic dist-upgrade

[Andres Rodriguez]

I deployed Xenial in this machine with MAAS. After deployment i had re-configured interfaces manually (on /etc/network/interfaces), and removed /etc/network/interfaces.d. At some point, I upgraded the machine from Xenial to Bionic, and everything was working just fine with /e/n/i.

About 2/3 weeks ago, I dist-upgraded bionic for the latest packages, and after reboot, networking didn't come up.

To recover the machine, what i did is:

1. From the console, brought up the interfaces manually (eno1)
2. added an IP address manually (ip addr add)
3. Configured netplan and applied the config:

network:
    version: 2
    renderer: networkd
    ethernets:
        eno1:
            dhcp4: no
            dhcp6: no
            addresses: [192.168.1.13/24]
            gateway4: 192.168.1.1
            nameservers:
                addresses: [8.8.8.8, 8.8.4.4]
        usb0:
            dhcp4: no
    bridges:
        br0:
            interfaces: [usb0]
            dhcp4: no
            addresses: [10.90.90.1/24]
            parameters:
                stp: false
                forward-delay: 0
                max-age: 0

5. Interfaces dont get configured correctly:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
17: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether ec:a8:6b:fd:ac:70 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.13/24 scope global eno1
       valid_lft forever preferred_lft forever
    inet6 fe80::eea8:6bff:fefd:ac70/64 scope link
       valid_lft forever preferred_lft forever
19: usb0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0e:c6:88:b7:9f brd ff:ff:ff:ff:ff:ff
    inet6 fe80::20e:c6ff:fe88:b79f/64 scope link
       valid_lft forever preferred_lft forever
22: wlp2s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether c4:d9:87:5b:42:62 brd ff:ff:ff:ff:ff:ff

6. on reboot, the machine goes back to have no networking again, at all.

Note that I also have /e/n/i configured.

[Andres Rodriguez (andreserl)]

I dont believe this is a cloud-init issue provided that cloud-init seems to not run networking on reboots, and networking is disabled:

ubuntu@maas00:/etc/cloud/cloud.cfg.d$ cat curtin-disable-cloudinit-networking.cfg
network: {config: disabled}

[Andres Rodriguez (andreserl)]

cloud-init-output.log after manually rebooting the machine.

[Steve Langasek (vorlon)]

> 3. Configured netplan and applied the config:
> 5. Interfaces dont get configured correctly:

Not sure what happened to 4 ;) But in any case, can you please confirm:
- what is the full set of config files under /etc/netplan after boot?
- what commands did you run to apply the config, and what was the output?
- what are the contents of eni (and /etc/network/interfaces.d) at this point?

[Andres Rodriguez (andreserl)]

https://pastebin.ubuntu.com/p/YPRxSrjHZ9/

[Steve Langasek (vorlon)]

Your config file is apparently named /etc/netplan/netplan.conf, which does not match the required "*.yaml" pattern (which is documented in the netplan(5) manpage and elsewhere).

[Ryan Harper (raharper)]

As per cloud-init networking disabled. Please reopen task if you find cloud-init is in the picture here.

[Andres Rodriguez (andreserl)]

Thanks to the investigation from Steve, it seems that during the dist-upgrade process ifupdown was removed due a transient conflict during the devel cycle. This caused it to be removed. It being removed didn't provide network. So this bug is basically a duplicate of #1756846.

17:21 < slangasek> roaksoax: according to your logs, during that upgrade the ifupdown package was removed (because of a transient conflict
                   during the devel cycle). you do not have the ifupdown package installed.
17:22 < slangasek> roaksoax: reinstalling ifupdown will fix this, and this is basically a duplicate of LP: #1756846