Merge ~b-candler/cloud-init:bridge-parameters into cloud-init:master

[Brian Candler]

Fixes KeyError for bridge with no "parameters:" setting

LP #1879673

Commit ded1ec81 introduced a regression whereby a bridge with no "parameters:" setting caused a KeyError exception.

[Brian Candler (b-candler)]

Note: commit ded1ec81 did include a test case, but didn't test the case where no "parameters:" were provided.
https://git.launchpad.net/cloud-init/commit/?id=ded1ec81

I don't have an environment set up to be able to run the test suite for cloud-init, but someone might want to add the missing test case.

[Brian Candler (b-candler)]

Moved to https://github.com/canonical/cloud-init/pull/423

Unmerged commits

b3cbd5a... by Brian Candler on 2020-06-06

Fixes KeyError for bridge with no "parameters:" setting

LP #1879673

diff --git a/cloudinit/net/network_state.py b/cloudinit/net/network_state.py
index f28973d..4456aea 100644
--- a/cloudinit/net/network_state.py
+++ b/cloudinit/net/network_state.py
@@ -725,7 +725,7 @@ class NetworkStateInterpreter(metaclass=CommandHandlerMeta):
             # we accept the fixed spelling, but write the old for compatability
             # Xenial does not have an updated netplan which supports the
             # correct spelling.  LP: #1756701
-            params = item_params['parameters']
+            params = item_params.get('parameters', {})
             grat_value = params.pop('gratuitous-arp', None)
             if grat_value:
                 params['gratuitious-arp'] = grat_value