availability zone not set

[Katherine Cox-Buday]

Reported on behalf of a user. Original bug here: https://github.com/juju/juju/issues/4452

When deploying on the latest juju stable release of 1.25.3 on ec2 in my python hook code I'm running the following code and it's showing None as the return value:
```
    az_info = os.environ.get('JUJU_AVAILABILITY_ZONE')
    log("AZ Info: " + az_info)
```
The ec2 region that I'm deploying on is us-west-2
In my juju status output I'm seeing the following for the machine:
```
31 started 1.25.3 54.213.132.207 i-eb50d82c trusty arch=amd64 cpu-cores=1 cpu-power=300 mem=3840M root-disk=8192M availability-zone=us-west-2b
```
I looked into the Go code and it appears that it's querying and setting the environment variable.
I also dropped into the install debug hook and tried to echo $JUJU_AVAILABILITY_ZONE and that also showed nothing. I think this is a bug but I'm not certain.

[Chris Holcombe (xfactor973)]

Here's the debug log of the ceph charm deployment: https://gist.github.com/cholcombe973/87089c093005eb37101a

[Ian Booth (wallyworld)]

The availability zone comes from what's recorded against the machine to which the unit is assigned. Can we get a mongo dump of the machine collection to inspect?

[Chris Holcombe (xfactor973)]

Yeah no problem. I'll upload it tomorrow

[Anastasia (anastasia-macmood)]

I have reproduced this on my environment.

We are not populating hook context. I have a fix and will propose it shortly.

[Anastasia (anastasia-macmood)]

Proposed for 1.25: https://github.com/juju/juju/pull/4603
Proposed for master: https://github.com/juju/juju/pull/4605

[Chris Holcombe (xfactor973)]

Awesome! Glad I'm not crazy :) Woo

On 03/02/2016 06:14 AM, Anastasia wrote:
> I have reproduced this on my environment.
>
> We are not populating hook context. I have a fix and will propose it
> shortly.
>

[Cheryl Jennings (cherylj)]

This was included in 1.25.4

[Ryan Beisner (1chb1n)]

Note: we are blocked on some deliverable work where the MAAS provider is required, and we're not able to observe MAAS zones in juju 1.25.3 or proposed 1.25.4 via JUJU_AVAILABILITY_ZONE.