How to?: Devices unmanaged by default, persist "nmcli managed yes" across reboots [debug log included]

[gima+ml networkmanager-list iki fi]

Hello,

# Purpose
To use NM to configure USB modem only and leave other devices unmanaged. 
Why? Because the machine in question is a router which has a complex 
network configuration.

# Description
According to the manual, NM can be configured to set all devices 
unmanaged, and make overrides per-device via DBUS API. I assumed this 
meant that NM also has a mechanism to persist overrides when devices are 
manually set as managed.

> $ cat '/etc/NetworkManager/conf.d/50-my.conf'
> [main]
> no-auto-default=*
>
> [device]
> managed=0
After starting NM, `nmcli dev` shows all devices as "unmanaged", which 
is correct. Executing the following command:
> $ nmcli dev set ttyUSB0 autoconnect yes managed yes
Causes the device to become managed, and because I have "gsm" connection 
defined, it will be automatically connected.

# Bug
The problem is that after a reboot, the device stays unmanaged. I assume 
it is either a bug or that there exists no mechanism to persist this 
manually set managed state for a device.

If this feature doesn't exist and needs to be implemented, I think it 
would be necessary to also implement a way for the device to know which 
connection to use (though I think this is already implemented somewhere 
else).

# Attachments
`at_startup.log` - trace logging of NM startup regarding the usbmodem
`after_cmd.log` - trace logging of NM after setting the device as 
managed and autoconnect

Attachment: at_startup.log
Description: Text Data

Attachment: after_cmd.log
Description: Text Data