Enable pipeline_yaml for mitaka and above

This configuration for pipeline.yaml is still valid for mitaka and
above, so adding this in.

The ceilometer-collector package is not available in newer openstack
releases, so basing this on QUEENS_SERVICES.

This should solve the custom requirement of pipeline moving forward.

Other fixes:
* Update test-requirements.txt for cffi and related pins.
* Update focal-xena bundle to fix memcached series bionic requirement.

Closes-Bug: 1938807
Change-Id: I1946b6f172cdae6f444d07999d5e54d4e11a450e

lib/ceilometer_utils.py

@@ -173,6 +173,10 @@ QUEENS_CONFIG_FILES = OrderedDict([
         'hook_contexts': [CustomSinksContext()],
         'services': QUEENS_SERVICES,
     }),
+    (CEILOMETER_PIPELINE_YAML, {
+        'hook_contexts': [CeilometerPipelineContext()],
+        'services': QUEENS_SERVICES,
+    }),
 ])
 
 CONFIG_FILES = OrderedDict([

test-requirements.txt

@@ -7,6 +7,8 @@
 #       requirements.  They are intertwined.  Also, Zaza itself should specify
 #       all of its own requirements and if it doesn't, fix it there.
 #
+pyparsing<3.0.0  # aodhclient is pinned in zaza and needs pyparsing < 3.0.0, but cffi also needs it, so pin here.
+cffi==1.14.6; python_version < '3.6'  # cffi 1.15.0 drops support for py35.
 setuptools<50.0.0  # https://github.com/pypa/setuptools/commit/04e3df22df840c6bb244e9b27bc56750c44b7c85
 
 requests>=2.18.4

tests/bundles/focal-xena.yaml

@@ -14,6 +14,8 @@ machines:
     constraints: mem=3072M
   '3':
   '4':
+    # This machine is for memcached that isn't focal enabled.
+    series: bionic
   '5':
   '6':
   '7':
@@ -62,6 +64,8 @@ applications:
   memcached:
     charm: cs:~memcached-team/memcached
     num_units: 1
+    # the memcached charm doesn't support focal yet.
+    series: bionic
     to:
       - '4'
 

unit_tests/test_ceilometer_utils.py

@@ -186,6 +186,9 @@ class CeilometerUtilsTest(CharmTestCase):
              '/etc/ceilometer/event_pipeline.yaml': [
                 'ceilometer-agent-central',
                 'ceilometer-agent-notification'],
+             '/etc/ceilometer/pipeline.yaml': [
+                'ceilometer-agent-central',
+                'ceilometer-agent-notification'],
              }
         )