Comment 0 for bug 1828299

[Impact]
This release contains both bug-fixes and new features and we would like to
make sure all of our supported customers have access to these improvements.
The notable ones are:

   * [d96a6a0] networkd: force bringing up devices with no IP addresses
      (LP: #1763608)
   * Reworked renderer choosing to avoid regression in default renderer when multiple files specify it globally (LP: #1825206) (already SRUed in a simpler form)
   * Fixed networkd activation. (LP: #1821867) (already SRUed)

See the changelog entry below for a full list of changes and bugs.

[Test Case]
The following development and SRU process was followed:
https://wiki.ubuntu.com/NetplanUpdates

Netplan contains an extensive integration test suite that is ran using
the SRU package for each releases. This test suite's results are available here:
http://autopkgtest.ubuntu.com/packages/n/netplan.io

A successful run is required before the proposed netplan package
can be let into -updates.

The netplan team will be in charge of attaching the artifacts and console
output of the appropriate run to the bug. Netplan team members will not
mark ‘verification-done’ until this has happened.

[Regression Potential]
In order to mitigate the regression potential, the results of the
aforementioned integration tests are attached to this bug.

<TODO: attach test artifacts for every SRU release, not a link as links expire>

[Discussion]
This addresses in priority an important issue with integration of netplan with openvswitch; where devices are hard to bring up to hand over to openvswitch: behavior was changed such that as soon as a device is listed in netplan config (even without an IP), it gets brought online by the networkd renderer. This is consistent with the idea of having only configured interfaces touched by netplan; if the name of the itnerface appears in netplan YAML, it gets configured (albeit without IP).

[Changelog]
ea47bd4 (tag: 0.97) parser: refactor / factor out validation and error reporting
a001750 parser: reorganize validation to happen in a single pass at the end of parsing
3e99f59 Revert "parser: fix explicit backend assignment due to file merging" (LP: #1825206)
3e732b7 (tag: 0.96.1) Fix failure in make install
a5389e5 doc: add notice about interfaces configured in YAML being brought up
16b297b Fix tests after reverting systemd-networkd.service's activation from network-online.
ef43dd5 Partially revert the change for enabling systemd-networkd. network-online.target may not be depended on by anything on minimal images, but multi-user.target already is. (LP: #1821867)
d96a6a0 networkd: force bringing up devices with no IP addresses (LP: #1763608)
fb71b87 Automatically skip tests when wifi is clearly unavailable