Fix Ocata to Pike upgrade

When upgrading from Ocata to Pike the context was not recognizing
Pike until a subsequent hook run. Resetting os release fixes this.

Enable xenia-pike amulet test.

Closes-Bug: #1723981

Change-Id: I67ec257f0a91cf4108de54a2cd93ab0cc3663376

hooks/neutron_api_utils.py

@@ -46,6 +46,7 @@ from charmhelpers.contrib.openstack.utils import (
     token_cache_pkgs,
     enable_memcache,
     CompareOpenStackReleases,
+    reset_os_release,
 )
 
 from charmhelpers.contrib.python.packages import (
@@ -559,6 +560,7 @@ def do_openstack_upgrade(configs):
     ]
     apt_update(fatal=True)
     apt_upgrade(options=dpkg_opts, fatal=True, dist=True)
+    reset_os_release()
     pkgs = determine_packages(new_src)
     # Sort packages just to make unit tests easier
     pkgs.sort()

templates/pike/neutron.conf

@@ -1,4 +1,4 @@
-# newton
+# pike
 ###############################################################################
 # [ WARNING ]
 # Configuration file maintained by Juju. Local changes may be overwritten.
@@ -16,6 +16,10 @@ rpc_workers = {{ workers }}
 
 router_distributed = {{ enable_dvr }}
 
+{% if dns_domain -%}
+dns_domain = {{ dns_domain }}
+{% endif -%}
+
 l3_ha = {{ l3_ha }}
 {% if l3_ha -%}
 max_l3_agents_per_router = {{ max_l3_agents_per_router }}

tox.ini

@@ -60,7 +60,7 @@ basepython = python2.7
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 commands =
-    bundletester -vl DEBUG -r json -o func-results.json gate-basic-xenial-mitaka --no-destroy
+    bundletester -vl DEBUG -r json -o func-results.json gate-basic-xenial-pike --no-destroy
 
 [testenv:func27-dfs]
 # Charm Functional Test