gateway4 and gateway6 have been deprecated in netplan

[ubuntu-server-builder]

This bug was originally filed in Launchpad as LP: #1992512

Launchpad details

affected_projects = []
assignee = aciba
assignee_name = Alberto Contreras
date_closed = 2023-02-22T16:52:23.434349+00:00
date_created = 2022-10-11T20:24:46.345984+00:00
date_fix_committed = 2022-11-18T09:09:16.690379+00:00
date_fix_released = 2023-02-22T16:52:23.434349+00:00
id = 1992512
importance = high
is_complete = True
lp_url = https://bugs.launchpad.net/cloud-init/+bug/1992512
milestone = None
owner = akutz
owner_name = Andrew Kutz
private = False
status = fix_released
submitter = akutz
submitter_name = Andrew Kutz
tags = []
duplicates = []

Launchpad user Andrew Kutz(akutz) wrote on 2022-10-11T20:24:46.345984+00:00

Per the netplan reference documentation (https://netplan.io/reference), the scalar fields "gateway4" and "gateway6" have been deprecated:

Deprecated, see Default routes. Set default gateway for IPv4/6, for manual address configuration. This requires setting addresses too. Gateway IPs must be in a form recognized by inet_pton(3). There should only be a single gateway per IP address family set in your global config, to make it unambiguous. If you need multiple default routes, please define them via routing-policy.

However, I checked, and nothing in the Cloud-Init bug tracker or GitHub repository indicates there are plans for Cloud-Init to address this change:

• https://bugs.launchpad.net/cloud-init?field.searchtext=gateway4
• https://github.com/canonical/cloud-init/search?q=gateway4&type=issues

Additionally:

• the Cloud-Init network_state module still uses both fields --

  cloud-init/cloudinit/net/network_state.py

  Lines 40 to 41 in cd2cca3

  	"gateway4",
  	"gateway6",

• the Cloud-Init netplan module still references both fields --

  cloud-init/cloudinit/net/netplan.py

  Lines 117 to 120 in cd2cca3

  	if ":" in gateway:
  	entry.update({"gateway6": gateway})
  	else:
  	entry.update({"gateway4": gateway})

• both fields are still part of the network unit tests --

  cloud-init/tests/unittests/test_net.py

  Lines 478 to 494 in cd2cca3

  	NETPLAN_DHCP_FALSE = """
  	version: 2
  	ethernets:
  	ens3:
  	match:
  	macaddress: 52:54:00:ab:cd:ef
  	dhcp4: false
  	dhcp6: false
  	addresses:
  	- 192.168.42.100/24
  	- 2001:db8::100/32
  	gateway4: 192.168.42.1
  	gateway6: 2001:db8::1
  	nameservers:
  	search: [example.com]
  	addresses: [192.168.42.53, 1.1.1.1]
  	"""

I am curious to find out:

• What is Cloud-Init's plan to handle the gateway4 and gateway6 fields?
• Will Cloud-Init deprecate them from their network v2 config to be aligned with netplan?
• Will Cloud-Init continue to support them and seamless produce the recommended default routes per netplan's documentation?
• What is the timeline for any such change or changes?

Thanks!

[ubuntu-server-builder]

Launchpad user James Falcon(falcojr) wrote on 2022-10-12T21:46:21.010523+00:00

Yeah, this is something I have noticed alread. I created a ticket internally to get it fixed "soon", but you're right in that there's nothing in Launchpad yet.

To your questions, this is my current thinking, but could change if needed:

For v1, the config won't change. We'll render the appropriate routes instead. For v2 not Ubuntu, we'll deprecate but still support it while probably throwing a warning for the old version. It's a little trickier for Ubuntu since we passthrough netplan config. On Ubuntu, I don't see us supporting the deprecated keys any longer than Netplan does. As far as timeline, we should have a fix ready by 23.1.

[ubuntu-server-builder]

Launchpad user Alberto Contreras(aciba) wrote on 2022-11-18T09:09:07.365214+00:00

Fix committed here: #1794

[ubuntu-server-builder]

Launchpad user shixuantong(sxt1001) wrote on 2022-12-10T06:47:41.581030+00:00

The problem seems to have been resolved enough to close it. There are a lot of open bugs.

[ubuntu-server-builder]

Launchpad user James Falcon(falcojr) wrote on 2022-12-12T13:29:28.837024+00:00

This has not yet been released upstream, so it will stay the current status until 23.1 is released.

[ubuntu-server-builder]

Launchpad user shixuantong(sxt1001) wrote on 2022-12-15T09:29:50.799987+00:00

ok. Thanks. I get it.

[ubuntu-server-builder]

Launchpad user Alberto Contreras(aciba) wrote on 2023-02-22T16:52:24.099276+00:00

This bug is believed to be fixed in cloud-init in version 23.1. If this is still a problem for you, please make a comment and set the state back to New

Thank you.