Scalability improvements for disabled services

Currently, every service has a play in site.yml that is executed, and
the role is skipped if the service is disabled. This can be slow,
particularly with many hosts, since each play takes time to setup, and
evaluate.

This change creates various Ansible groups for hosts with services
enabled at the beginning of the playbook. If a service is disabled, this
new group will have no hosts, and the play for that service will be a
noop.

I have tested this on a laptop using an inventory with 12 hosts (each
pointing to my laptop via SSH), and a config file that disables every
service. Time taken to run 'kolla-ansible deploy':

Before change: 2m30s
After change: 0m14s

During development I also tried an approach using an 'include_role' task
for each service. This was not as good, taking 1m00s.

The downsides to this patch are that there is a large number of tasks at
the beginning of the playbook to perform the grouping, and every play
for a disabled service now outputs this warning message:

[WARNING]: Could not match supplied host pattern, ignoring: enable_foo_True

This is because if the service is disabled, there are no hosts in the
group. This seems like a reasonable tradeoff.

Change-Id: Ie56c270b26926f1f53a9582d451f4bb2457fbb67

ansible/site.yml

@@ -32,23 +32,109 @@
         - (ansible_play_batch | length) != (groups['all'] | length)
   tags: always
 
+# NOTE(mgoddard): In large environments, even tasks that are skipped can take a
+# significant amount of time. This is an optimisation to prevent any tasks
+# running in the subsequent plays for services that are disabled.
+- name: Group hosts based on configuration
+  hosts: all
+  gather_facts: false
+  tasks:
+    - name: Group hosts based on OpenStack release
+      group_by:
+        key: "openstack_release_{{ openstack_release }}"
+
+    - name: Group hosts based on Kolla action
+      group_by:
+        key: "kolla_action_{{ kolla_action }}"
+
+    - name: Group hosts based on enabled services
+      group_by:
+        key: "{{ item }}"
+      with_items:
+        - enable_aodh_{{ enable_aodh | bool }}
+        - enable_barbican_{{ enable_barbican | bool }}
+        - enable_blazar_{{ enable_blazar | bool }}
+        - enable_ceilometer_{{ enable_ceilometer | bool }}
+        - enable_ceph_{{ enable_ceph | bool }}
+        - enable_chrony_{{ enable_chrony | bool }}
+        - enable_cinder_{{ enable_cinder | bool }}
+        - enable_cloudkitty_{{ enable_cloudkitty | bool }}
+        - enable_collectd_{{ enable_collectd | bool }}
+        - enable_congress_{{ enable_congress | bool }}
+        - enable_designate_{{ enable_designate | bool }}
+        - enable_elasticsearch_{{ enable_elasticsearch | bool }}
+        - enable_etcd_{{ enable_etcd | bool }}
+        - enable_freezer_{{ enable_freezer | bool }}
+        - enable_glance_{{ enable_glance | bool }}
+        - enable_gnocchi_{{ enable_gnocchi | bool }}
+        - enable_grafana_{{ enable_grafana | bool }}
+        - enable_haproxy_{{ enable_haproxy | bool }}
+        - enable_heat_{{ enable_heat | bool }}
+        - enable_horizon_{{ enable_horizon | bool }}
+        - enable_hyperv_{{ enable_hyperv | bool }}
+        - enable_influxdb_{{ enable_influxdb | bool }}
+        - enable_ironic_{{ enable_ironic | bool }}
+        - enable_iscsid_{{ enable_iscsid | bool }}
+        - enable_kafka_{{ enable_kafka | bool }}
+        - enable_karbor_{{ enable_karbor | bool }}
+        - enable_keystone_{{ enable_keystone | bool }}
+        - enable_kibana_{{ enable_kibana | bool }}
+        - enable_kuryr_{{ enable_kuryr | bool }}
+        - enable_magnum_{{ enable_magnum | bool }}
+        - enable_manila_{{ enable_manila | bool }}
+        - enable_mariadb_{{ enable_mariadb | bool }}
+        - enable_memcached_{{ enable_memcached | bool }}
+        - enable_mistral_{{ enable_mistral | bool }}
+        - enable_monasca_{{ enable_monasca | bool }}
+        - enable_mongodb_{{ enable_mongodb | bool }}
+        - enable_multipathd_{{ enable_multipathd | bool }}
+        - enable_murano_{{ enable_murano | bool }}
+        - enable_neutron_{{ enable_neutron | bool }}
+        - enable_nova_{{ enable_nova | bool }}
+        - enable_octavia_{{ enable_octavia | bool }}
+        - enable_opendaylight_{{ enable_opendaylight | bool }}
+        - enable_openvswitch_{{ enable_openvswitch | bool }}_enable_ovs_dpdk_{{ enable_ovs_dpdk | bool }}
+        - enable_outward_rabbitmq_{{ enable_outward_rabbitmq | bool }}
+        - enable_panko_{{ enable_panko | bool }}
+        - enable_prometheus_{{ enable_prometheus | bool }}
+        - enable_qdrouterd_{{ enable_qdrouterd | bool }}
+        - enable_rabbitmq_{{ enable_rabbitmq | bool }}
+        - enable_rally_{{ enable_rally | bool }}
+        - enable_redis_{{ enable_redis | bool }}
+        - enable_sahara_{{ enable_sahara | bool }}
+        - enable_searchlight_{{ enable_searchlight | bool }}
+        - enable_senlin_{{ enable_senlin | bool }}
+        - enable_skydive_{{ enable_skydive | bool }}
+        - enable_solum_{{ enable_solum | bool }}
+        - enable_swift_{{ enable_swift | bool }}
+        - enable_tacker_{{ enable_tacker | bool }}
+        - enable_telegraf_{{ enable_telegraf | bool }}
+        - enable_tempest_{{ enable_tempest | bool }}
+        - enable_trove_{{ enable_trove | bool }}
+        - enable_vitrage_{{ enable_vitrage | bool }}
+        - enable_vmtp_{{ enable_vmtp | bool }}
+        - enable_watcher_{{ enable_watcher | bool }}
+        - enable_zookeeper_{{ enable_zookeeper | bool }}
+        - enable_zun_{{ enable_zun | bool }}
+  tags: always
+
 - import_playbook: detect-release.yml
   vars:
-    detect_release_hosts: all
+    detect_release_hosts: openstack_release_auto
 
 - name: Apply role prechecks
   gather_facts: false
-  hosts:
+  # Apply only when kolla action is 'precheck'.
-    - all
+  hosts: kolla_action_precheck
   roles:
     - role: prechecks
-      when: kolla_action == "precheck"
 
 - name: Apply role chrony
   gather_facts: false
   hosts:
     - chrony-server
     - chrony
+    - '&enable_chrony_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: chrony,
@@ -59,6 +145,7 @@
   gather_facts: false
   hosts:
     - haproxy
+    - '&enable_haproxy_True'
   roles:
     - { role: haproxy,
         tags: haproxy,
@@ -304,7 +391,9 @@
 
 - name: Apply role collectd
   gather_facts: false
-  hosts: collectd
+  hosts:
+    - collectd
+    - '&enable_collectd_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: collectd,
@@ -313,7 +402,9 @@
 
 - name: Apply role zookeeper
   gather_facts: false
-  hosts: zookeeper
+  hosts:
+    - zookeeper
+    - '&enable_zookeeper_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: zookeeper,
@@ -322,7 +413,9 @@
 
 - name: Apply role elasticsearch
   gather_facts: false
-  hosts: elasticsearch
+  hosts:
+    - elasticsearch
+    - '&enable_elasticsearch_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: elasticsearch,
@@ -331,7 +424,9 @@
 
 - name: Apply role influxdb
   gather_facts: false
-  hosts: influxdb
+  hosts:
+    - influxdb
+    - '&enable_influxdb_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: influxdb,
@@ -342,6 +437,7 @@
   gather_facts: false
   hosts:
     - telegraf
+    - '&enable_telegraf_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: telegraf,
@@ -352,6 +448,7 @@
   gather_facts: false
   hosts:
     - redis
+    - '&enable_redis_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: redis,
@@ -360,7 +457,9 @@
 
 - name: Apply role kibana
   gather_facts: false
-  hosts: kibana
+  hosts:
+    - kibana
+    - '&enable_kibana_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: kibana,
@@ -369,7 +468,9 @@
 
 - name: Apply role mariadb
   gather_facts: false
-  hosts: mariadb
+  hosts:
+    - mariadb
+    - '&enable_mariadb_True'
   roles:
     - { role: mariadb,
         tags: mariadb,
@@ -377,7 +478,9 @@
 
 - name: Apply role memcached
   gather_facts: false
-  hosts: memcached
+  hosts:
+    - memcached
+    - '&enable_memcached_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: memcached,
@@ -392,6 +495,7 @@
     - prometheus-mysqld-exporter
     - prometheus-haproxy-exporter
     - prometheus-cadvisor
+    - '&enable_prometheus_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: prometheus,
@@ -403,6 +507,7 @@
   hosts:
     - iscsid
     - tgtd
+    - '&enable_iscsid_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: iscsi,
@@ -413,6 +518,7 @@
   gather_facts: false
   hosts:
     - multipathd
+    - '&enable_multipathd_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: multipathd,
@@ -421,7 +527,9 @@
 
 - name: Apply role rabbitmq
   gather_facts: false
-  hosts: rabbitmq
+  hosts:
+    - rabbitmq
+    - '&enable_rabbitmq_True'
   roles:
     - { role: rabbitmq,
         tags: rabbitmq,
@@ -439,7 +547,9 @@
 
 - name: Apply role rabbitmq (outward)
   gather_facts: false
-  hosts: outward-rabbitmq
+  hosts:
+    - outward-rabbitmq
+    - '&enable_outward_rabbitmq_True'
   roles:
     - { role: rabbitmq,
         tags: rabbitmq,
@@ -456,7 +566,9 @@
 
 - name: Apply role qdrouterd
   gather_facts: false
-  hosts: qdrouterd
+  hosts:
+    - qdrouterd
+    - '&enable_qdrouterd_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: qdrouterd,
@@ -465,7 +577,9 @@
 
 - name: Apply role etcd
   gather_facts: false
-  hosts: etcd
+  hosts:
+    - etcd
+    - '&enable_etcd_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: etcd,
@@ -474,7 +588,9 @@
 
 - name: Apply role keystone
   gather_facts: false
-  hosts: keystone
+  hosts:
+    - keystone
+    - '&enable_keystone_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: keystone,
@@ -490,6 +606,7 @@
     - ceph-nfs
     - ceph-osd
     - ceph-rgw
+    - '&enable_ceph_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: ceph,
@@ -498,7 +615,9 @@
 
 - name: Apply role kafka
   gather_facts: false
-  hosts: kafka
+  hosts:
+    - kafka
+    - '&enable_kafka_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: kafka,
@@ -518,7 +637,9 @@
 
 - name: Apply role karbor
   gather_facts: false
-  hosts: karbor
+  hosts:
+    - karbor
+    - '&enable_karbor_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: karbor,
@@ -532,6 +653,7 @@
     - swift-container-server
     - swift-object-server
     - swift-proxy-server
+    - '&enable_swift_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: swift,
@@ -544,6 +666,7 @@
     - ceph-mon
     - glance-api
     - glance-registry
+    - '&enable_glance_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: glance,
@@ -557,6 +680,7 @@
     - ironic-conductor
     - ironic-inspector
     - ironic-pxe
+    - '&enable_ironic_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: ironic,
@@ -571,6 +695,7 @@
     - cinder-backup
     - cinder-scheduler
     - cinder-volume
+    - '&enable_cinder_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: cinder,
@@ -587,6 +712,7 @@
     - nova-consoleauth
     - nova-novncproxy
     - nova-scheduler
+    - '&enable_nova_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: nova,
@@ -595,7 +721,9 @@
 
 - name: Apply role opendaylight
   gather_facts: false
-  hosts: opendaylight
+  hosts:
+    - opendaylight
+    - '&enable_opendaylight_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: opendaylight,
@@ -606,6 +734,7 @@
   gather_facts: false
   hosts:
     - openvswitch
+    - '&enable_openvswitch_True_enable_ovs_dpdk_False'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: openvswitch,
@@ -616,6 +745,7 @@
   gather_facts: false
   hosts:
     - openvswitch
+    - '&enable_openvswitch_True_enable_ovs_dpdk_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: ovs-dpdk,
@@ -626,6 +756,7 @@
   gather_facts: false
   hosts:
     - hyperv
+    - '&enable_hyperv_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: nova-hyperv,
@@ -646,6 +777,7 @@
     - neutron-metering-agent
     - compute
     - manila-share
+    - '&enable_neutron_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: neutron,
@@ -656,6 +788,7 @@
   gather_facts: false
   hosts:
     - compute
+    - '&enable_kuryr_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: kuryr,
@@ -668,6 +801,7 @@
     - heat-api
     - heat-api-cfn
     - heat-engine
+    - '&enable_heat_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: heat,
@@ -678,6 +812,7 @@
   gather_facts: false
   hosts:
     - horizon
+    - '&enable_horizon_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: horizon,
@@ -689,6 +824,7 @@
   hosts:
     - murano-api
     - murano-engine
+    - '&enable_murano_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: murano,
@@ -702,6 +838,7 @@
     - solum-worker
     - solum-deployer
     - solum-conductor
+    - '&enable_solum_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: solum,
@@ -713,6 +850,7 @@
   hosts:
     - magnum-api
     - magnum-conductor
+    - '&enable_magnum_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: magnum,
@@ -725,6 +863,7 @@
     - mistral-api
     - mistral-engine
     - mistral-executor
+    - '&enable_mistral_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: mistral,
@@ -736,6 +875,7 @@
   hosts:
     - sahara-api
     - sahara-engine
+    - '&enable_sahara_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: sahara,
@@ -746,6 +886,7 @@
   gather_facts: false
   hosts:
     - mongodb
+    - '&enable_mongodb_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: mongodb,
@@ -754,7 +895,9 @@
 
 - name: Apply role panko
   gather_facts: false
-  hosts: panko-api
+  hosts:
+    - panko-api
+    - '&enable_panko_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: panko,
@@ -769,6 +912,7 @@
     - manila-data
     - manila-share
     - manila-scheduler
+    - '&enable_manila_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: manila,
@@ -782,6 +926,7 @@
     - gnocchi-api
     - gnocchi-metricd
     - gnocchi-statsd
+    - '&enable_gnocchi_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: gnocchi,
@@ -796,6 +941,7 @@
     - ceilometer-central
     - ceilometer-notification
     - ceilometer-compute
+    - '&enable_ceilometer_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: ceilometer,
@@ -816,6 +962,7 @@
     - monasca-thresh
     - monasca-notification
     - monasca-persister
+    - '&enable_monasca_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: monasca,
@@ -829,6 +976,7 @@
     - aodh-evaluator
     - aodh-listener
     - aodh-notifier
+    - '&enable_aodh_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: aodh,
@@ -841,6 +989,7 @@
     - barbican-api
     - barbican-keystone-listener
     - barbican-worker
+    - '&enable_barbican_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: barbican,
@@ -853,6 +1002,7 @@
     - congress-api
     - congress-policy-engine
     - congress-datasource
+    - '&enable_congress_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: congress,
@@ -863,6 +1013,7 @@
   gather_facts: false
   hosts:
     - tempest
+    - '&enable_tempest_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: tempest,
@@ -879,6 +1030,7 @@
     - designate-worker
     - designate-sink
     - designate-backend-bind9
+    - '&enable_designate_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: designate,
@@ -887,7 +1039,9 @@
 
 - name: Apply role rally
   gather_facts: false
-  hosts: rally
+  hosts:
+    - rally
+    - '&enable_rally_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: rally,
@@ -898,6 +1052,7 @@
   gather_facts: false
   hosts:
     - vmtp
+    - '&enable_vmtp_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: vmtp,
@@ -910,6 +1065,7 @@
     - trove-api
     - trove-conductor
     - trove-taskmanager
+    - '&enable_trove_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: trove,
@@ -922,6 +1078,7 @@
     - watcher-api
     - watcher-engine
     - watcher-applier
+    - '&enable_watcher_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: watcher,
@@ -932,6 +1089,7 @@
   gather_facts: false
   hosts:
     - grafana
+    - '&enable_grafana_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: grafana,
@@ -943,6 +1101,7 @@
   hosts:
     - cloudkitty-api
     - cloudkitty-processor
+    - '&enable_cloudkitty_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: cloudkitty,
@@ -954,6 +1113,7 @@
   hosts:
     - freezer-api
     - freezer-scheduler
+    - '&enable_freezer_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: freezer,
@@ -965,6 +1125,7 @@
   hosts:
     - senlin-api
     - senlin-engine
+    - '&enable_senlin_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: senlin,
@@ -976,6 +1137,7 @@
   hosts:
     - searchlight-api
     - searchlight-listener
+    - '&enable_searchlight_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: searchlight,
@@ -987,6 +1149,7 @@
   hosts:
     - tacker-server
     - tacker-conductor
+    - '&enable_tacker_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: tacker,
@@ -1000,6 +1163,7 @@
     - octavia-health-manager
     - octavia-housekeeping
     - octavia-worker
+    - '&enable_octavia_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: octavia,
@@ -1012,6 +1176,7 @@
     - zun-api
     - zun-wsproxy
     - zun-compute
+    - '&enable_zun_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: zun,
@@ -1023,6 +1188,7 @@
   hosts:
     - skydive-agent
     - skydive-analyzer
+    - '&enable_skydive_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: skydive,
@@ -1037,6 +1203,7 @@
     - vitrage-notifier
     - vitrage-collector
     - vitrage-ml
+    - '&enable_vitrage_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: vitrage,
@@ -1048,6 +1215,7 @@
   hosts:
     - blazar-api
     - blazar-manager
+    - '&enable_blazar_True'
   serial: '{{ kolla_serial|default("0") }}'
   roles:
     - { role: blazar,