Comment 8 for bug 2008952

It doesn't seem to be caused by a race between networkd and NetworkManager.

I reproduced the issue with qemu here and I see the name resolution failure happening few seconds before NetworkManager started.

From /var/log/cloud-init.log:

2023-03-09 19:17:58,443 - util.py[DEBUG]: Getting data from <class 'cloudinit.sources.DataSourceNoCloud.DataSourceNoCloudNet'> failed
Traceback (most recent call last):
...
cloudinit.url_helper.UrlError: HTTPConnectionPool(host='boot.linuxgroove.com', port=80): Max retries exceeded with url: /ubuntu/23.04/meta-data (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x7f650b663610>:
Failed to establish a new connection: [Errno -3] Temporary failure in name resolution'))

From systemd's journal
Mar 09 19:18:01 ubuntu systemd[1]: Starting NetworkManager.service - Network Manager...

(edit)

resolved wasn't running as well

2023-03-09T19:18:01.712656+00:00 ubuntu systemd[1]: Starting systemd-resolved.service - Network Name Resolution...

but it seems my instance had a nameserver:

2023-03-09 19:17:58,500 - stages.py[INFO]: Applying network configuration from initramfs bringup=True: {'config': [{'type': 'physical', 'name': 'ens3', 'subnets': [{'type': 'dhcp', 'control': 'manual', 'netmask': '255.255.255.0', 'broadc
ast': '10.0.2.255', 'gateway': '10.0.2.2', 'dns_nameservers': ['10.0.2.3']}], 'mac_address': '52:54:00:12:34:56'}], 'version': 1}