inject git sha into juju binaries

[Ian Booth]

juju version should report git sha as well as version number
jujud startup shoud log git sha as well as version number
(needs change to juju build job)

caas operator build job needs to tag docker image with sha as well as juju version number
juju k8s provisioner should look for image tagged with sha and fall back to just version number when sha not available (eg for developers who build locally)

[Anastasia (anastasia-macmood)]

PR for 2.6: https://github.com/juju/juju/pull/10428

[Harry Pidcock (hpidcock)]

Broke the k8s work into https://github.com/juju/juju/pull/10435

[Anastasia (anastasia-macmood)]

This work will not be backported to 2.6.

[Richard Harding (rharding)]

I was looking for this today to tell what the controller was running in upgrade scenarios. It'd be awesome if it was part of the show-controller output.

Is the gist of this setup for 2.7-rc1?

[Harry Pidcock (hpidcock)]

Still pending on new snap building in CI