Charm cannot be deployed, fails on install hook with gpg error

[Jeff Pihach]

When deploying the recommended precise or trusty mysql charms on lxc or ec2 it fails in the install hook with:

2014-09-04 00:24:39 INFO install Executing: gpg --ignore-time-conflict --no-options --no-default-keyring --secret-keyring /tmp/tmp.niSJy48FrC --trustdb-name /etc/apt/trustdb.gpg --keyring /etc/apt/trusted.gpg --primary-keyring /etc/apt/trusted.gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv undefined
2014-09-04 00:24:39 INFO install gpg: "undefined" not a key ID: skipping
2014-09-04 00:24:39 INFO install Traceback (most recent call last):
2014-09-04 00:24:39 INFO install File "/var/lib/juju/agents/unit-mysql-0/charm/hooks/install", line 16, in <module>
2014-09-04 00:24:39 INFO install add_source(utils.config_get('source'), utils.config_get('key'))
2014-09-04 00:24:39 INFO install File "/var/lib/juju/agents/unit-mysql-0/charm/hooks/charmhelpers/fetch/__init__.py", line 188, in add_source
2014-09-04 00:24:39 INFO install key])
2014-09-04 00:24:39 INFO install File "/usr/lib/python2.7/subprocess.py", line 511, in check_call
2014-09-04 00:24:39 INFO install raise CalledProcessError(retcode, cmd)
2014-09-04 00:24:39 INFO install subprocess.CalledProcessError: Command '['apt-key', 'adv', '--keyserver', 'hkp://keyserver.ubuntu.com:80', '--recv', u'undefined']' returned non-zero exit status 2
2014-09-04 00:24:39 ERROR juju.worker.uniter uniter.go:486 hook failed: exit status 1

[Charles Butler (lazypower)]

I've validated the charm works in both trusty/precise variants on 3 of 6 substrates.

Local, AWS, and MAAS

Im' unable to reproduce this behavior.

[Jeff Pihach (hatch)]

Simply doing
juju bootstrap
juju deploy mysql
Started the charm up without issue.

However I was able to reproduce the issue with the following steps:

I'm not sure if all of these steps are required, these were just the ones which would reproduce the failure 100%

Using 1.20.6-trusty-amd64 on ec2

juju bootstrap
juju deploy juju-gui --to=0
juju set juju-gui juju-gui-source="develop"

Once it spins up then open the GUI and log in

Search for 'Ghost' in the charm browser
Drag the Ghost charm to the canvas and click the Commit/Confirm buttons in the bottom right to get it spinning up
Now search for 'MySQL'
Drag the Trusty MySQL charm to the canvas and Commit/Confirm
Now relate the Ghost charm to the MySQL charm
Commit/Confirm

Now after a while the MySQL charm will fail with the previous error in it's install hook

[Jeff Pihach (hatch)]

Output from `juju run --service mysql 'config-get'`:

sql 'config-get'
binlog-format: MIXED
block-size: 5
ceph-osd-replication-count: 2
dataset-size: 80%
flavor: distro
ha-bindiface: eth0
ha-mcastport: 5411
key: undefined
max-connections: -1
nagios_context: juju
preferred-storage-engine: InnoDB
query-cache-size: 0
query-cache-type: "OFF"
rbd-name: mysql1
source: undefined
tuning-level: safest
vip: ""
vip_cidr: 24
vip_iface: eth0

[Jeff Pihach (hatch)]

  mysql:
    charm: cs:trusty/mysql-4
    exposed: false
    relations:
      cluster:
      - mysql
      db:
      - ghost
    units:
      mysql/0:
        agent-state: error
        agent-state-info: 'hook failed: "install"'
        agent-version: 1.20.7
        machine: "2"
        public-address: ec2-54-197-90-141.compute-1.amazonaws.com

[Jeff Pihach (hatch)]

This appears to be an issue with the develop branch of the Juju GUI setting config fields without a defined default as `undefined`