Un-hardcode wsgi parameters

This patch adds abbility to configure the count of wsgi processes and
threads. The default parameters left intact to maintain backward
compatibility.

Closes-Bug: PROD-35385
Change-Id: I808e60d2db9b071a85adb840ce61592f49b62d91
diff --git a/README.rst b/README.rst
index 6b33e7a..f51f533 100644
--- a/README.rst
+++ b/README.rst
@@ -31,6 +31,7 @@
         enable_force_upload: true
         availability_zone_fallback: True
         image_conversion_dir: /var/tmp/cinder/conversion
+        wsgi_processes_count: 5
         concurrency:
           lock_path: '/var/lock/cinder'
         database:
diff --git a/cinder/files/pike/cinder-wsgi.conf b/cinder/files/pike/cinder-wsgi.conf
index b228a06..486bc19 100644
--- a/cinder/files/pike/cinder-wsgi.conf
+++ b/cinder/files/pike/cinder-wsgi.conf
@@ -2,7 +2,7 @@
 Listen {{ controller.osapi.host }}:8776
 
 <VirtualHost {{ controller.osapi.host }}:8776>
-    WSGIDaemonProcess cinder-wsgi processes=5 threads=1 user=cinder group=cinder display-name=%{GROUP}
+    WSGIDaemonProcess cinder-wsgi processes={{ controller.get('wsgi_processes_count', '5') }} threads=1 user=cinder group=cinder display-name=%{GROUP}
     WSGIProcessGroup cinder-wsgi
     WSGIScriptAlias / /usr/bin/cinder-wsgi
     WSGIApplicationGroup %{GLOBAL}
diff --git a/cinder/files/queens/cinder-wsgi.conf b/cinder/files/queens/cinder-wsgi.conf
index b228a06..486bc19 100644
--- a/cinder/files/queens/cinder-wsgi.conf
+++ b/cinder/files/queens/cinder-wsgi.conf
@@ -2,7 +2,7 @@
 Listen {{ controller.osapi.host }}:8776
 
 <VirtualHost {{ controller.osapi.host }}:8776>
-    WSGIDaemonProcess cinder-wsgi processes=5 threads=1 user=cinder group=cinder display-name=%{GROUP}
+    WSGIDaemonProcess cinder-wsgi processes={{ controller.get('wsgi_processes_count', '5') }} threads=1 user=cinder group=cinder display-name=%{GROUP}
     WSGIProcessGroup cinder-wsgi
     WSGIScriptAlias / /usr/bin/cinder-wsgi
     WSGIApplicationGroup %{GLOBAL}