Sync charm-helpers

Change-Id: Ic7cf6265426b467756bc1ee9343b87011bc838bc
Signed-off-by: Raven Kaur <raven.kaur@canonical.com>

charmhelpers/contrib/openstack/context.py

@@ -1697,29 +1697,33 @@ MAX_DEFAULT_WORKERS = 4
 DEFAULT_MULTIPLIER = 2
 
 
-def _calculate_workers():
+def _calculate_workers(multiplier=None):
     '''
-    Determine the number of worker processes based on the CPU
-    count of the unit containing the application.
+    Determine the number of worker processes based on the CPU count of the
+    unit containing the application, scaled by the provided multiplier or
+    the worker-multiplier configuration option.
 
     Workers will be limited to MAX_DEFAULT_WORKERS in
-    container environments where no worker-multipler configuration
-    option been set.
+    container environments  when no multiplier is
+    provided and worker-multiplier configuration option has not been set.
 
+    @param multiplier: float: scaling factor for CPU count
     @returns int: number of worker processes to use
     '''
-    multiplier = config('worker-multiplier')
+    cpu_scaling_factor = multiplier
+    if cpu_scaling_factor is None or cpu_scaling_factor <= 0:
+        cpu_scaling_factor = config('worker-multiplier')
 
     # distinguish an empty config and an explicit config as 0.0
-    if multiplier is None:
-        multiplier = DEFAULT_MULTIPLIER
+    if cpu_scaling_factor is None:
+        cpu_scaling_factor = DEFAULT_MULTIPLIER
 
-    count = int(_num_cpus() * multiplier)
+    count = int(_num_cpus() * cpu_scaling_factor)
     if count <= 0:
         # assign at least one worker
         count = 1
 
-    if config('worker-multiplier') is None:
+    if multiplier is None and config('worker-multiplier') is None:
         # NOTE(jamespage): Limit unconfigured worker-multiplier
         #                  to MAX_DEFAULT_WORKERS to avoid insane
         #                  worker configuration on large servers
@@ -1770,6 +1774,29 @@ class WSGIWorkerConfigContext(WorkerConfigContext):
         enable_wsgi_socket_rotation = config('wsgi-socket-rotation')
         if enable_wsgi_socket_rotation is None:
             enable_wsgi_socket_rotation = True
+
+        try:
+            admin_worker_multiplier = config('admin-worker-multiplier')
+        except Exception:
+            admin_worker_multiplier = None
+
+        if admin_worker_multiplier is None or admin_worker_multiplier <= 0:
+            admin_processes = int(math.ceil(
+                self.admin_process_weight * total_processes))
+        else:
+            admin_processes = _calculate_workers(admin_worker_multiplier)
+
+        try:
+            public_worker_multiplier = config('public-worker-multiplier')
+        except Exception:
+            public_worker_multiplier = None
+
+        if public_worker_multiplier is None or public_worker_multiplier <= 0:
+            public_processes = int(math.ceil(
+                self.public_process_weight * total_processes))
+        else:
+            public_processes = _calculate_workers(public_worker_multiplier)
+
         ctxt = {
             "service_name": self.service_name,
             "user": self.user,
@@ -1778,10 +1805,8 @@ class WSGIWorkerConfigContext(WorkerConfigContext):
             "admin_script": self.admin_script,
             "public_script": self.public_script,
             "processes": int(math.ceil(self.process_weight * total_processes)),
-            "admin_processes": int(math.ceil(self.admin_process_weight *
-                                             total_processes)),
-            "public_processes": int(math.ceil(self.public_process_weight *
-                                              total_processes)),
+            "admin_processes": admin_processes,
+            "public_processes": public_processes,
             "threads": 1,
             "wsgi_socket_rotation": enable_wsgi_socket_rotation,
         }