Comment 4 for bug 1551747

This is breaking cloud-init on AWS for us with 16.04 hvm:ebs-ssd (ami-7a138709).

The networking.service unit goes into failed state and cloud-init metadata crawler fails and falls back to local DataSource, skipping provisioning of ssh keys etc.

Jun 01 19:45:07 ip-172-31-13-182 ifup[928]: bound to 172.31.13.182 -- renewal in 1373 seconds.
Jun 01 19:45:07 ip-172-31-13-182 ifup[928]: run-parts: /etc/network/if-up.d/ubuntu-fan exited with return code 1
Jun 01 19:45:07 ip-172-31-13-182 ifup[928]: Failed to bring up ens3.
Jun 01 19:45:07 ip-172-31-13-182 systemd[1]: networking.service: Main process exited, code=exited, status=1/FAILURE
Jun 01 19:45:07 ip-172-31-13-182 systemd[1]: Failed to start Raise network interfaces.
Jun 01 19:45:07 ip-172-31-13-182 systemd[1]: Dependency failed for Initial cloud-init job (metadata service crawler).
Jun 01 19:45:07 ip-172-31-13-182 systemd[1]: cloud-init.service: Job cloud-init.service/start failed with result 'dependency'.
Jun 01 19:45:07 ip-172-31-13-182 systemd[1]: networking.service: Unit entered failed state.
Jun 01 19:45:07 ip-172-31-13-182 systemd[1]: networking.service: Failed with result 'exit-code'.

[... snip ...]

Jun 01 19:45:09 ip-172-31-13-182 cloud-init[1347]: [CLOUDINIT] cc_final_message.py[WARNING]: Used fallback datasource

FWIW, this happened after installing docker.io, which pulls in ubuntu-fan as a dependency.

A manual `/usr/sbin/fanctl net start ens3` exits 1, without any output.