Dryrun or config test option

[Joshua Powers]

Feature request for a --dryrun or config test option to validate 1) I have valid YAML and 2) the keys and values are consumable/readable by netplan. This is essentially what generate does, but stopping before generating part.

Use Case 1:

I am a new user of netplan and I do not know what I am doing. I am experimenting with netplan and I do not want to apply changes to my local system. I do however want to test my YAML to validate that netplan can parse it correctly.

Use Case 2:

I am a sys admin of lots of servers with more complex networking requirements where I am adding all sorts of vlan, bonding, bridging options. Before spending time checking on a system I want to write YAML on my local development system and know that netplan will read it without wasting time on syntax or incorrect keys.

[Mathieu Trudel-Lapierre (cyphermox)]

Yes! This ties in to other future feature ideas too. Triaging.

[Jean-Daniel Dupas (xooloo)]

Use Case 3:
  I'm a sysadmin with lots of server where network config is generated by scripts. Such scripts should be able to validate that the generated file is valid before deploying it.

[Daniel Axtens (daxtens)]

I think this is now provided by 'netplan try' in Bionic.

Does anyone object to this being marked as Fix Released?

Regards,
Daniel

[Joshua Powers (powersj)]

Use case 1 is covered by netplan try. Use case 2 and 3 are not.

[Daniel Axtens (daxtens)]

Usecase 2 can be covered with netplan generate --root-dir: create foo/etc/netplan, put the files in there, and do 'netplan generate --root-dir foo'. I think that might cover case 3 as well?

[Joshua Powers (powersj)]

I would have expected it to fail with a message about the incorrect YAML:
https://paste.ubuntu.com/p/dv3dgjjQVJ/

I also strongly dislike modifying my own system to test something I would want used on a different system.

[Ryan Harper (raharper)]

I think the netplan python wrapper needs help, what you can do is:

# /lib/netplan/generate -r test-dir test.yaml
Invalid YAML at test.yaml line 8 column 17: mapping values are not
allowed in this context
# echo $?
1
On Mon, Jul 23, 2018 at 4:11 PM Joshua Powers <email address hidden> wrote:
>
> I would have expected it to fail with a message about the incorrect YAML:
> https://paste.ubuntu.com/p/dv3dgjjQVJ/
>
> I also strongly dislike modifying my own system to test something I
> would want used on a different system.
>
> --
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> https://bugs.launchpad.net/bugs/1735318
>
> Title:
> Dryrun or config test option
>
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[Daniel Axtens (daxtens)]

OK, so we've basically landed in the territory of LP: #1701434.

I don't know if we want to just mark one of those as duplicates of the other, but clearly the python wrapper needs some more smarts around this.

I'll have a look and see if I can make some sense of the different failure modes and which need to be signalled back through the exit code of netplan apply.

[Daniel Axtens (daxtens)]

It looks like at least some of this changed between Bionic and Cosmic - here with a netplan 0.39:

root@netplan:~# netplan apply
Error in network definition /etc/netplan/50-cloud-init.yaml line 5 column 0: unknown key xxnetwork
root@netplan:~# echo $?
78

At the very least now generate gets an exit code. Do we just need to get this backported?