Bug 1744427

Summary: [RHEL 8.1] A host with invalid hostname can't activate its network interface by NetworkManager
Product: Red Hat Enterprise Linux 8 Reporter: Beni Pelled <bpelled>
Component: NetworkManagerAssignee: Beniamino Galvani <bgalvani>
Status: CLOSED ERRATA QA Contact: Desktop QE <desktop-qa-list>
Severity: medium Docs Contact:
Priority: medium    
Version: 8.1CC: atragler, bgalvani, fgiudici, lrintel, pasik, rkhan, sukulkar, thaller, vbenes, wshi
Target Milestone: rc   
Target Release: 8.0   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: NetworkManager-1.22.0-0.2.el8 Doc Type: If docs needed, set a value
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Clone Of: Environment:
Last Closed: 2020-04-28 16:53:06 UTC Type: Bug
Regression: --- Mount Type: ---
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Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description Beni Pelled 2019-08-22 07:28:22 UTC 
Description of problem:
A host with invalid hostname can't activate its network interface by NetworkManager
(I'm not sure if it's a bug or a new implementation for NetworkManager)

Version-Release number of selected component (if applicable):
RHEL-8.1.0-20190821.0


How reproducible:
100%

Steps to Reproduce:
1. Install RHEL-8.1 with valid hostname (ex. bpelled)
2. Make sure you can reload network interface and stay connected by 'nmcli con down <ifname> && nmcli con up <ifname>'
3. Change hostname to invalid name by 'hostnamectl set-hostname bpelled_invalid_hostname'
4. Try to reload the network interface by 'nmcli con down <ifname> && nmcli con up <ifname>'


Actual results:
An attempt to reload the interface after renaming the hostname will fail with 'Error: Connection activation failed: dhcp client failed to start'

The following info/warn will be in 'journalctl -xe NM_DEVICE=<ifname>':

Aug 22 09:45:02 bpelled_invalid_hostname NetworkManager[5698]: <info>  [1566456302.7398] device (ens3): Activation: starting connection 'ens3' (7a2a3a9b-f268-4571-8903-69db66a8e99b)
Aug 22 09:45:02 bpelled_invalid_hostname NetworkManager[5698]: <info>  [1566456302.7399] device (ens3): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')
Aug 22 09:45:02 bpelled_invalid_hostname NetworkManager[5698]: <info>  [1566456302.7404] device (ens3): state change: prepare -> config (reason 'none', sys-iface-state: 'managed')
Aug 22 09:45:02 bpelled_invalid_hostname NetworkManager[5698]: <info>  [1566456302.7856] device (ens3): state change: config -> ip-config (reason 'none', sys-iface-state: 'managed')
Aug 22 09:45:02 bpelled_invalid_hostname NetworkManager[5698]: <info>  [1566456302.7859] dhcp4 (ens3): activation: beginning transaction (timeout in 45 seconds)
Aug 22 09:45:02 bpelled_invalid_hostname NetworkManager[5698]: <warn>  [1566456302.7860] device (ens3): failure to start DHCP: failed to set DHCP hostname: Invalid argument
Aug 22 09:45:02 bpelled_invalid_hostname NetworkManager[5698]: <info>  [1566456302.7860] device (ens3): state change: ip-config -> failed (reason 'dhcp-start-failed', sys-iface-state: 'managed')
Aug 22 09:45:02 bpelled_invalid_hostname NetworkManager[5698]: <warn>  [1566456302.7869] device (ens3): Activation: failed for connection 'ens3'
Aug 22 09:45:02 bpelled_invalid_hostname NetworkManager[5698]: <info>  [1566456302.7871] device (ens3): state change: failed -> disconnected (reason 'none', sys-iface-state: 'managed')

Expected results:
Active Network interface.

Additional info:
Following [1] I tried to set hostname-mode=none on /etc/NetworkManager/NetworkManager.conf but I didn't manage to get it works.

[1] https://manpages.debian.org/unstable/network-manager/NetworkManager.conf.5.en.html
Comment 1 Beniamino Galvani 2019-10-17 16:09:20 UTC 
Merge request:

https://gitlab.freedesktop.org/NetworkManager/NetworkManager/merge_requests/310
Comment 2 Beniamino Galvani 2019-10-18 04:38:49 UTC 
Fixed:
https://gitlab.freedesktop.org/NetworkManager/NetworkManager/commit/a5f22dbc5d026104485c8098a0499135ba779589
Comment 4 Vladimir Benes 2019-12-12 14:18:41 UTC 
covered by gen_activate_with_incorrect_hostname
Comment 6 errata-xmlrpc 2020-04-28 16:53:06 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2020:1847