Move watcher precheck into its own role

Refers to https://review.openstack.org/#/c/399354/

Change-Id: I28f77d996593978caa3cb63f1c0b0fb096d2d62a
Partially-implements: blueprint condition-pre-check

ansible/roles/haproxy/tasks/precheck.yml

@@ -35,3 +35,14 @@
     - enable_glance | bool
     - inventory_hostname in groups['haproxy']
     - "{{ 'glance_registry' not in haproxy_stat }}"
+
+- name: Checking free port for watcher API HAProxy
+  wait_for:
+    host: "{{ kolla_internal_vip_address }}"
+    port: "{{ watcher_api_port }}"
+    connect_timeout: 1
+    state: stopped
+  when:
+    - enable_watcher | bool
+    - "{{ 'watcher_api' not in haproxy_stat }}"
+    - inventory_hostname in groups['haproxy']

ansible/roles/prechecks/tasks/port_checks.yml

@@ -890,26 +890,6 @@
     - enable_mistral | bool
     - inventory_hostname in groups['haproxy']
 
-- name: Checking free port for Watcher API
-  wait_for:
-    host: "{{ hostvars[inventory_hostname]['ansible_' + api_interface]['ipv4']['address'] }}"
-    port: "{{ watcher_api_port }}"
-    connect_timeout: 1
-    state: stopped
-  when:
-    - enable_watcher | bool
-    - inventory_hostname in groups['watcher-api']
-
-- name: Checking free port for Watcher API HAProxy
-  wait_for:
-    host: "{{ kolla_internal_vip_address }}"
-    port: "{{ watcher_api_port }}"
-    connect_timeout: 1
-    state: stopped
-  when:
-    - enable_watcher | bool
-    - inventory_hostname in groups['haproxy']
-
 - name: Checking free port for Searchlight API
   wait_for:
     host: "{{ hostvars[inventory_hostname]['ansible_' + api_interface]['ipv4']['address'] }}"

ansible/roles/watcher/tasks/precheck.yml

 ---
+- name: Get container facts
+  kolla_container_facts:
+    name:
+      - watcher_api
+  register: container_facts
+
+- name: Checking free port for watcher API
+  wait_for:
+    host: "{{ hostvars[inventory_hostname]['ansible_' + api_interface]['ipv4']['address'] }}"
+    port: "{{ watcher_api_port }}"
+    connect_timeout: 1
+    state: stopped
+  when:
+    - container_facts['watcher_api'] is not defined
+    - inventory_hostname in groups['watcher-api']