Disable c-bak and etcd3 in grenade jobs

Grenade only runs tempest smoke tests and there are no
cinder-backup service related smoke tests in the main
tempest repo so running the c-bak service on the primary
and subnode (in multinode jobs) is just a waste of resources
since it's not used in testing.

Similarly, etcd3 is really only interesting for cinder in
a multinode job but in grenade multinode jobs etcd3 is not
enabled on the subnode, so only the primary node cinder
services are configured to use etcd3, so again it's a waste
of resources.

There is a theory that bug 1844929 is failing primarily on
OVH nodes because they aggressively restrict iops so we're
running into swap issues [1]. Freeing up more resources on
the nodes used in grenade jobs might alleviate some of that
swap pressure.

To do this using the feature test matrix in devstack-gate
the test_matrix.py script has to be updated such that
services can be added/removed per config rather than per
feature because otherwise grenade says it wants cinder but
cannot remove cinder-specific services like c-bak.

[1] http://lists.openstack.org/pipermail/openstack-discuss/2019-November/010506.html

Change-Id: Ide146793053ae6b62f93a5af45c6130a21514e87
Related-Bug: #1844929

roles/test-matrix/files/features.yaml

@@ -22,6 +22,9 @@ config:
   # feature changes for different test matrixes
   grenade:
     rm-features: [trove, sahara, neutron-adv, horizon]
+    # Disable c-bak and etcd3 since they are not used in grenade runs
+    # and just take up resources (iops) which can cause gate failures.
+    rm-services: [c-bak, etcd3]
   tempest:
     features: [tempest]
   cells:

roles/test-matrix/library/test_matrix.py

@@ -73,7 +73,7 @@ def configs_from_env():
     return configs
 
 
-def calc_services(branch, features, role):
+def calc_services(branch, features, configs, role):
     LOG.debug('Role: %s', role)
     services = set()
     for feature in features:
@@ -99,6 +99,25 @@ def calc_services(branch, features, role):
             services.difference_update(
                 grid_feature[branch].get('rm-services', []))
 
+    # Finally, calculate any services to add/remove per config.
+    # do all the adds first
+    for config in configs:
+        if config in GRID['config']:
+            add_services = GRID['config'][config].get('services', [])
+            if add_services:
+                LOG.debug('Adding services for config %s: %s',
+                          config, add_services)
+                services.update(add_services)
+
+    # deletes always trump adds
+    for config in configs:
+        if config in GRID['config']:
+            rm_services = GRID['config'][config].get('rm-services', [])
+            if rm_services:
+                LOG.debug('Removing services for config %s: %s',
+                          config, rm_services)
+                services.difference_update(rm_services)
+
     return sorted(list(services))
 
 
@@ -188,7 +207,7 @@ def main():
     features = calc_features(branch, configs)
     LOG.debug("Features: %s " % features)
 
-    services = calc_services(branch, features, role)
+    services = calc_services(branch, features, configs, role)
     LOG.debug("Services: %s " % services)
 
     if opts.ansible:

test-features.sh

@@ -22,7 +22,7 @@ TEMPEST_NEUTRON_MASTER="n-api,n-api-meta,n-cpu,n-sch,n-cond,n-novnc,g-api,g-reg,
 
 TEMPEST_HEAT_SLOW_MASTER="n-api,n-api-meta,n-cpu,n-sch,n-cond,n-novnc,g-api,g-reg,key,c-api,c-vol,c-sch,c-bak,s-proxy,s-account,s-container,s-object,mysql,rabbit,dstat,peakmem_tracker,etcd3,tempest,q-svc,q-agt,q-dhcp,q-l3,q-meta,q-metering,placement-api"
 
-GRENADE_NEW_MASTER="n-api,n-api-meta,n-cpu,n-sch,n-cond,n-novnc,g-api,g-reg,key,c-api,c-vol,c-sch,c-bak,s-proxy,s-account,s-container,s-object,mysql,rabbit,dstat,peakmem_tracker,etcd3,tempest,placement-api"
+GRENADE_NEW_MASTER="n-api,n-api-meta,n-cpu,n-sch,n-cond,n-novnc,g-api,g-reg,key,c-api,c-vol,c-sch,s-proxy,s-account,s-container,s-object,mysql,rabbit,dstat,peakmem_tracker,tempest,placement-api"
 
 # Utility function for tests
 function assert_list_equal {