Change resource.resource_metadata to text type

The existing resource.resource_metadata column size is 5k chars,
which is not enough for some large JSON metadata payload,
so change to as Text column to make sure store all JSON string
without truncating.

Fixes bug #1220683

Change-Id: Ide8c6b94f1ae56d76fe3d5b6238d44e498e67c03
Ensure combination alarm evaluator can be loaded

Fixes bug 1237578

Previously combination alarms were always skipped as the evaluator
was missing from the loadable stevedore extensions.

Change-Id: I9d164fb2a89ee9931fc032d93ad4a26ba6887f0b
Ensure combination alarms can be evaluated

Fixes bug 1237589

Previously the retrieval of state for the constituent alarms always
failed for combination alarms, due to an incorrect attribute of
ceilometerclient being used. As a result combination alarms could
never be successfully evaluated.

Now the correct pluralized attribute is used.

Change-Id: Id58a5d185854367e5a08011048774ab5aed93d4e
Set python-six minimum version

missing python-six minimum version from the requirements.txt
set the min version to 1.4.1

fixes bug: #1237205

Change-Id: I6b821e4500178f4ca50e05c4893c8bbaacfc238e
Merge "Change resource.resource_metadata to text type"
Merge "Set python-six minimum version"
Merge "Ensure combination alarms can be evaluated"
Make sample pipeline optional

This patch makes it possible to turn off the sample pipeline
and decouples the AMQP consumer configuration for the collector
from the sample plugins. This will make it easier to stand up
different types of pipelines in the future.

Change-Id: I10a0e54510b532d8e948e372078278dbf011f06c
Related-To: blueprint notification-pipelines
second revision, WIP

Change-Id: I894def28ee512cf3134214346968a3b6f2682af3
switched to using EnabledExtensionManager to black-list extensions

Change-Id: I50f65e5faa49c3f3cdc698deb513a943a048ca96
removed initialize_service_hook logic for store_events

Change-Id: I9625751f504377b6903ccbba462949a15e4ad97a
moved to using built-in map for sample extensions

Change-Id: I863fcfda8d983705133a7aab63602c129af64ddc
clean up

Change-Id: I69751b147755aee3ce736d7d98db08437a58d456
clean up 2

Change-Id: I09bc2fbee3f65a020359e5ae2f70a9cc34dc5391
clean up and a few new tests

Change-Id: I02db104e505fbc60ba2bc3d027ab38a918fc77d1
test_initialize_service_hook

Change-Id: Ib7abaad7c4cc0f9c255a2ed17c50b659682f444e
removed exchange configuration

Change-Id: I5718a1e8654dec8725919acc168213fde862f934
final tests added

Change-Id: I7e46c5308b4aa4718d524b19bb3c9cdba0c7e3d0