Comment 0 for bug 1975576

[Impact]
 * using network-manager (20/stable - 711 + netplan backend) and try to connect to router with WPA3 Security fails via "nmcli"
 * error message: "Error: Connection activation failed: (7) Secrets were required, but not provided."
 * related to a problem with the generation of the netplan configuration, when key management is "sae"
 * This breaks a customer setup in Ubuntu Core 20
 * The upstream fix solves the issue, by avoiding a shortcut in libnetplan's NetworkManager/keyfile renderer: https://github.com/canonical/netplan/pull/279

[Test Plan]
 * Use a system with NetworkManager+netplan integration installed (e.g. Ubuntu Core, network-manager snap)
 * Create a WPA3 connection via "nmcli":
$ sudo nmcli c add con-name test3 type wifi ssid ubuntu-wpa2-wpa3-mixed ifname wlan0
Connection 'test3' (a89c5eb9-c5a4-426e-ae86-7fca5161cfcc) successfully added.
$ sudo nmcli c modify test3 wifi-sec.key-mgmt sae wifi-sec.psk test1234

 * Make sure it contains the psk/credentials ("test1234") and "key-mgmt: sae":
$ nmcli c show test3 --show-secrets | egrep "wireless-security.(key-mgmt|psk)"
802-11-wireless-security.key-mgmt: sae
802-11-wireless-security.psk: test1234
802-11-wireless-security.psk-flags: 0 (none)

 * Make sure the netplan YAML contains "networkmanager.passthrough.key-mgmt: sae" and "auth.password: test1234":
$ netplan get | grep password
$ netplan get | grep key-mgmt

[Where problems could occur]
 * The upload changes netplan's NetworkManager (keyfile) backend renderer. So any unexpected failure could break configuration of NetworkManager connection profiles via netplan.

[Other Info]
 * upstream fix: https://github.com/canonical/netplan/pull/279
 * shipped as a hotfix in ppa:canonical-foundations/ubuntu-image: https://launchpad.net/~canonical-foundations/+archive/ubuntu/ubuntu-image/+sourcepub/13638052/+listing-archive-extra