[FFe] New upstream snapshot

[Dan Watkins]

We would like to upload a new upstream snapshot of cloud-init to disco. This includes a number of desirable bug fixes, in particular:

* clean: correctly determine the path for excluding seed directory (LP: #1818571)
* azure: Filter list of ssh keys pulled from fabric
* EC2: Rewrite network config on AWS Classic instances every boot

And includes these new features/behaviour changes:

* Stop disabling apt pipelining (LP: #1794982)
* Enable encrypted_data_bag_secret support for Chef (LP: #1817082)

[Dan Watkins (oddbloke)]

The full list of changes, generated from the git log:

- Support locking user with usermod if passwd is not available. [Scott Moser]
- Example for Microsoft Azure data disk added. [Anton Olifir]
- clean: correctly determine the path for excluding seed directory
  (LP: #1818571)
- helpers/openstack: Treat unknown link types as physical (LP: #1639263)
- drop Python 2.6 support and our NIH version detection
- tip-pylint: Fix assignment-from-return-none errors
- net: append type:dhcp[46] only if dhcp[46] is True in v2 netconfig
  [Kurt Stieger] (LP: #1818032)
- cc_apt_pipelining: stop disabling pipelining by default (LP: #1794982)
- tests: fix some slow tests and some leaking state
- util: don't determine string_types ourselves
- cc_rsyslog: Escape possible nested set (LP: #1816967)
- Enable encrypted_data_bag_secret support for Chef
  [Eric Williams] (LP: #1817082)
- azure: Filter list of ssh keys pulled from fabric [Jason Zions (MSFT)]
- doc: update merging doc with fixes and some additional details/examples
- tests: integration test failure summary to use traceback if empty error
- This is to fix https://bugs.launchpad.net/cloud-init/+bug/1812676
  [Vitaly Kuznetsov]
- EC2: Rewrite network config on AWS Classic instances every boot
  [Guilherme G. Piccoli] (LP: #1802073)
- netinfo: Adjust ifconfig output parsing for FreeBSD ipv6 entries
  (LP: #1779672)
- netplan: Don't render yaml aliases when dumping netplan (LP: #1815051)
- add PyCharm IDE .idea/ path to .gitignore [Dominic Schlegel]
- correct grammar issue in instance metadata documentation
  [Dominic Schlegel] (LP: #1802188)
- clean: cloud-init clean should not trace when run from within cloud_dir
  (LP: #1795508)
- Resolve flake8 comparison and pycodestyle over-ident issues [Paride Legovini]

[Steve Langasek (vorlon)]

Because this package has an SRU exception process, I am content to approve a standing FFe for this up to final freeze, provided the SRU exception process is followed for the uploads to devel also.

Past final freeze, the SRU exception process can also be followed for uploads that will be directed to the -updates pocket.

[Dan Watkins (oddbloke)]

Thanks Steve!

We're going to use block-proposed on this bug to hold cloud-init in -proposed whilst we perform the manual SRU testing process.

[Dan Watkins (oddbloke)]

The testing is complete, and the SRU bug (bug 1819067) will be updated with the results shortly. In the meantime, they can be examined at https://github.com/cloud-init/ubuntu-sru/tree/master/20190307 so I'm going to remove block-proposed.