Could not set hostname: Permission denied

[kaizen1]

systemd 245 (245.4-4ubuntu3.2)
OS: Ubuntu 20.04 minimal Google Cloud image

Expected behaviour you didn't see

I would expect systemd-networkd to set the hostname

Unexpected behaviour you saw

hostname could not be set due to permission error.

Steps to reproduce the problem
Reboot the VM
Run sudo systemctl status systemd-networkd

Get:

● systemd-networkd.service - Network Service
Loaded: loaded (/lib/systemd/system/systemd-networkd.service; enabled; vendor preset: enabled)
Active: active (running) since Mon 2020-08-03 17:25:10 UTC; 5min ago
TriggeredBy: ● systemd-networkd.socket
Docs: man:systemd-networkd.service(8)
Main PID: 606 (systemd-network)
Status: "Processing requests..."
Tasks: 1 (limit: 2010)
Memory: 1.4M
CGroup: /system.slice/systemd-networkd.service
└─606 /lib/systemd/systemd-networkd

systemd[1]: Starting Network Service...
systemd-networkd[606]: Enumeration completed
systemd[1]: Started Network Service.
systemd-networkd[606]: ens4: DHCPv4 address 10.142.0.11/32 via 10.142.0.1
systemd-networkd[606]: Could not set hostname: Permission denied

[yuwata]

Are systemd-hostnamed and polkit installed? networkd itself does not set hostname, but set it through hostnamed.

[yuwata]

Not sure, but maybe related to #13501.

[kaizen1]

Is this correct? Or should it be active? Seems odd. It's a fresh GCP VM image. Ubuntu 20.04 minimal. よろしくお願い

More Info:
libpolkit-gobject-1-0:
Installed: 0.105-26ubuntu1

After seeing the below status. I manually started systemd-hostnamed.
Then rebooted. Then I see systemd-hostnamed is Active: active (running), but I still get:
systemd-networkd[213]: Could not set hostname: Permission denied

● systemd-hostnamed.service - Hostname Service
Loaded: loaded (/lib/systemd/system/systemd-hostnamed.service; static; vendor preset: enabled)
Active: inactive (dead)
Docs: man:systemd-hostnamed.service(8)
man:hostname(5)
man:machine-info(5)
https://www.freedesktop.org/wiki/Software/systemd/hostnamed

Aug 05 12:23:57 vm1 systemd[1]: Starting Hostname Service...
Aug 05 12:23:57 vm1 systemd[1]: Started Hostname Service.
Aug 05 12:24:27 vm1 systemd[1]: systemd-hostnamed.service: Succeeded.
Aug 05 12:28:09 vm1 systemd[1]: Starting Hostname Service...
Aug 05 12:28:09 vm1 systemd[1]: Started Hostname Service.
Aug 05 12:28:42 vm1 systemd[1]: systemd-hostnamed.service: Succeeded.

[yuwata]

libpolkit-gobject-1-0

Is this only installed package related to polkit? I do not know the exact name of polkit package in Ubuntu. But libpolkit-gobject-1-0 seems not relevant. Please install polkit.

Or should it be active?

No. It is not necessary to enable and start hostnamed. It is automatically started when hostname change is requested (e.g., by hostnamectl or networkd).

[yuwata]

Ah, maybe policykit.
https://packages.ubuntu.com/focal/policykit-1

[kaizen1]

sudo apt install policykit-1
No more permissions error from: sudo systemctl status systemd-networkd
Thank you @yuwata !
どうもどうも！

[yuwata]

どういたしまして。