netplan fails through to generic error handler when specifying bridge

[Peter Goodall]

Ubuntu 18.04.1 LTS, Release: 18.04

adding a specification for a bridge to /etc/netplan/01-my_network.yaml causes a fail-over to a catch-all exception handler. No useful debugging information is given. ( i wish you had markdown )

$ sudo netplan try -debug
Error while loading /etc/netplan/01-my_network.yaml, aborting.

the source file has contents:

"
# Let netplan manage all devices on this system
network:
  version: 2
  renderer: networkd
  ethernets:
    enp5s0:
      dhcp4: yes
      dhcp6: no

   bridges:
    lxdbr0:
      dhcp4: yes
      interfaces:
        - enp5s0
"

It loads without error if the bridges section is removed. The file is a simple example from https://netplan.io/examples#bridging
I have tried several other configurations, all fail when bridging is attempted.

I believe the netplan source is at: https://github.com/CanonicalLtd/netplan/blob/master/netplan/configmanager.py

I'm guessing the handler should not be activated.

        except (IOError, yaml.YAMLError): # pragma: nocover (filesystem failures/invalid YAML)
            logging.error('Error while loading {}, aborting.'.format(yaml_file))
            sys.exit(1)

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: netplan.io 0.40.1~18.04.2
ProcVersionSignature: Ubuntu 4.15.0-42.45-generic 4.15.18
Uname: Linux 4.15.0-42-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair nvidia_modeset nvidia
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Fri Nov 23 11:34:52 2018
InstallationDate: Installed on 2018-11-08 (14 days ago)
InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20181107)
ProcEnviron:
 LANGUAGE=en_AU:en
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_AU.UTF-8
 SHELL=/usr/bin/zsh
SourcePackage: netplan.io
UpgradeStatus: No upgrade log present (probably fresh install)

[Peter Goodall (pjgoodall)]

I'm not asserting that my .yaml source is correct, just that a more specific/informative error handler should have been invoked.

[Mathieu Trudel-Lapierre (cyphermox)]

Yes, absolutely. In fact, I fixed this already:

$ ~/bin/netplan --root-dir=scratch/ --debug generate
DEBUG:command generate: running ['/lib/netplan/generate', '--root-dir', 'scratch/']
** (generate:18683): DEBUG: 16:41:58.422: Processing input file scratch//etc/netplan/01-my_network.yaml..
scratch//etc/netplan/01-my_network.yaml:9:4: Invalid YAML: inconsistent indentation:
   bridges:
   ^

The changes are available in Ubuntu 19.04 already; will be made available to other releases soon as stable updates.

FWIW, the issue is one space too much before "bridges:". Sorry I couldn't get to respond to this sooner!

[Peter Goodall (pjgoodall)]

Thanks Mathieu. Looking forward to the fix being released into Bionic.