Comment 7 for bug 1819014

Verification-done for cosmic:

With a netplan config setting up only wireless:

network:
    version: 2
    renderer: networkd
    wifis:
        wlan0:
            dhcp4: yes
            dhcp6: yes
            access-points:
                cyphermox.net:
                    password: [redacted]

The system appears to come up properly in relatively short time; definitely less than the previously visible 2mn to bring up with wifi.

ubuntu@ubuntu:~$ uptime
 18:22:31 up 1 min, 1 user, load average: 2.44, 1.08, 0.40
ubuntu@ubuntu:~$ systemd-analyze time
Startup finished in 55.346s (userspace)
graphical.target reached after 42.780s in userspace
ubuntu@ubuntu:~$ systemd-analyze blame | grep wait-online
            57ms systemd-networkd-wait-online.service
ubuntu@ubuntu:~$ systemd-analyze blame | grep netplan
ubuntu@ubuntu:~$ systemd-analyze blame | grep wpa
            57ms wpa_supplicant.service
ubuntu@ubuntu:~$ ip addr
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
2: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether b8:27:eb:1b:f5:e2 brd ff:ff:ff:ff:ff:ff
3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether b8:27:eb:4e:a0:b7 brd ff:ff:ff:ff:ff:ff
    inet 10.3.1.227/22 brd 10.3.3.255 scope global dynamic wlan0
       valid_lft 14288sec preferred_lft 14288sec
    inet6 2001:470:b0cc::78f/128 scope global dynamic noprefixroute
       valid_lft 28688sec preferred_lft 17888sec
    inet6 fe80::ba27:ebff:fe4e:a0b7/64 scope link
       valid_lft forever preferred_lft forever
ubuntu@ubuntu:~$ dpkg -l netplan.io | grep ii
ii netplan.io 0.96-0ubuntu0.18.10.2 arm64 YAML network configuration abstraction for various backends