Comment 2 for bug 1234365

The Hadoop charm uses `.` as word delimiters for its configuration options instead of `-` or `_` as every other charm I could find. This is interfering with our nested databinding parsing code.

Although you are able to deploy the Hadoop charm via the command line you aren't able to set any config option with a `.` delimiter so these config keys are invalid and should have failed validation.

After looking at the charm it looks like it keys off of the config options to build an XML configuration for Hadoop so one could change the juju config keys fairly easily without impacting the resulting config.