Reload nginx instead of restart

We don't need to restart nginx - we can instead just reload the
service. Additionally, as more services move to use nginx frontend, it
would be bad to restart all NGinx services at the same time.

For now we need to investigate the impact of reloads in UWsgi before
moving over to a "reload" on UWsgi.

Change-Id: I60e370e784a1ff3a0f5bf8551be804bf05d8bb43

handlers/main.yml

@@ -70,10 +70,10 @@
     - "{{ nova_services['nova-compute']['group'] in group_names }}"
     - "{{ nova_services['nova-compute']['condition'] | default(true) }}"
 
-- name: Restart Nginx
+- name: Reload Nginx
   systemd:
     name: nginx
-    state: restarted
+    state: reloaded
   register: nova_nginx_restart
   until: nova_nginx_restart | success
   retries: 5

tasks/nova_placement_nginx.yml

@@ -19,7 +19,7 @@
     groups: nova
     append: yes
   notify:
-    - Restart Nginx
+    - Reload Nginx
   tags:
     - nova-install
 
@@ -28,7 +28,7 @@
     path: /etc/nginx/sites-enabled/default
     state: absent
   notify:
-    - Restart Nginx
+    - Reload Nginx
 
 - name: Configure custom nginx log format
   lineinfile:
@@ -36,7 +36,7 @@
     dest: "/etc/nginx/nginx.conf"
     line: "log_format custom '{{ nova_placement_nginx_access_log_format_combined }} {{ nova_placement_nginx_access_log_format_extras }}';"
   notify:
-    - Restart Nginx
+    - Reload Nginx
 
 # Configure app
 - name: Configure virtual hosts
@@ -44,7 +44,7 @@
     src: nova-placement-nginx.conf.j2
     dest: "/etc/nginx/{{ nova_nginx_conf_path }}/nova_placement_api.conf"
   notify:
-    - Restart Nginx
+    - Reload Nginx
 
 - name: Link to enable virtual hosts
   file:
@@ -53,4 +53,4 @@
     state: link
   when: ansible_os_family == "Debian"
   notify:
-    - Restart Nginx
+    - Reload Nginx