Add more features for openstack orchestration

[bzwei]

The following methods are added to Fog::Orchestration::OpenStack

1. describe_stack - get more details of a stack, including parameters, output etc.
2. list_stack_resources - get a list of all resources generated by the stack
3. get_template - get the template used to generate the stack

[kbrock]

Spoke with Bill.

Looks like there is an outstanding datamodel request at fog/fog-core#45.
There is also an outstanding PR that leverages these changes. It does not support open stack yet, but the author does share that there is one in the works: fog#2971

If nothing else, we want to rebase to recent master.

[Fryguy]

@bzwei Is this required for the refresh code?

[bzwei]

Yes. This is needed for openstack refresh.

[jrafanie]

@bzwei @kbrock is this implementation the same that's in those fog pull requests? I don't see the same commits here so I'm not sure. It's tricky to implement our own fork of the code. I would rather help get the right code merged upstream and then use that version.

[bzwei]

The fog community was refactoring the related code but halted, those PRs were never merged. The changes were too big and I'm afraid we can help to make the refactoring completed. My implementation here was to add a few methods to their existing code with the old style.

[jrafanie]

@bzwei from the link to fog's issue 45 from @kbrock's comment, it looks like they're either waiting for us or it's going to be implemented in a separate library. Let's not fork fog until we have exhausted all options. Maintaining forks for libraries that we often need to rebase from upstream changes is a huge technical debt.

[bzwei]

The PR is now abandoned. The new implementation fog#3412 has been merged to fog/fog