remove default=None for config options

In the cfg module default=None is set as the default value.

Change-Id: Idb78d3e25c79aba0d74fdd747efe2e17b6faa129
Closes-Bug: #1323975
Implement caching of resource attributes

The default caching mode cache_local will return the previously
resolved value if it is available.

Whenever any resource changes state, all resource attribute caches
are cleared just in case the state change has side-effects in
other resources.

The caching mode cache_none performs no caching, and is chosen
for attributes which are one of the following:
* Derived from any resource's metadata, resource data or resource_id
* An API call which returns a secret

Caching currently only exists for the duration of the parser.Stack
object, but there is future potential for a caching mode which
caches attributes spanning multiple requests.

Closes-Bug: #1321970

Change-Id: I01bf2983b726f0e81a2b8d5be94627353bdeb406
Use entry points for config generation

This starts using entry points to generate configuration for the
common.config and the common.wsgi modules, as they use entries with the
same name in different groups.
This also removes configuration for sslutils which is unused, and
re-enable the check for up-to-date configuration.

Co-Authored-By: ala.rezmerita@cloudwatt.com
Closes-Bug: #1288586
Change-Id: If48c62bbb2b1fb641791dad56f7f905e483080fa
Include parameter name in error message

Including parameter name in StackValidationFailed exception
message.

Change-Id: I9d8f4e4a1986496d9be96f0e2a272cbc4da92b49
Closes-Bug: #1324968
Adding error message for output description

All caught exceptions should be displayed in output section.

Change-Id: I217bb52e33c3f0d20c3d01e75326687cc713d90a
Related-Bug: #1273490
Don't log entire template

In the engine, we log the entire template at info level
It's probably better, and more secure, to just log a message
saying the create/update is happening.

Change-Id: I6490656e0b6737c34f6a5abb36aa736946a7a44c
Implement resize of Cinder volumes

This patch adds update capabilities to volume size.
The new size must be bigger than old one (as supported by Cinder).
If the volume is attached, it is first detached, then resized and
attached again to the same mount on the same server.

Known limitations:
user has to care for herself about (un)mounting the volume
from within the instance OS and resizing the file system after
resizing the volume.

Change-Id: I7c54b18eb865d0786ec5e3f50c92aeabdaa80a64
Implements: blueprint update-cinder-volume
Fix physical_resource_name for Nova server

This patch fixes the problem caused by the overridden
physical_resource_name() in OS::Nova::Server resource.  If the name
assigned to the Server resource is used for Keystone user creation,
there is a higher possibility of name conflicts.

Change-Id: I5eff496aef8949db9c1f9865e8de33d2b58c7a7f
Closes-Bug: #1324499
Add OS::Glance::Image resource

Add OS::Glance::Image resource.
Implements: blueprint glance-image

Change-Id: If0b5f322da758973d6b47f9ca6888fef40f92f45
Merge "Use entry points for config generation"
Merge "Adding error message for output description"
Merge "Fix physical_resource_name for Nova server"
Merge "Implement resize of Cinder volumes"
Merge "remove default=None for config options"
Merge "Include parameter name in error message"
Merge "Don't log entire template"
Merge "Implement caching of resource attributes"
Merge "Add OS::Glance::Image resource"