Implement container-cluster aware capacity determination

* Added two settings values for declaring absolute cpu and memory
  capacity that will be picked up by the capacity utility methods
* installer inventory variables for controlling the amount of cpu and
  memory container requests/limits for the awx task containers
* Added fixed values for cpu and memory container requests for other
  containers
* configmap uses the declared inventory variables to define the
  capacity inputs that will be used by AWX to correspond to the same
  inputs for requests/limits on the deployment.

awx/main/utils/common.py

@@ -646,6 +646,15 @@ def get_cpu_capacity():
     from django.conf import settings
     settings_forkcpu = getattr(settings, 'SYSTEM_TASK_FORKS_CPU', None)
     env_forkcpu = os.getenv('SYSTEM_TASK_FORKS_CPU', None)
+
+    settings_abscpu = getattr(settings, 'SYSTEM_TASK_ABS_CPU', None)
+    env_abscpu = os.getenv('SYSTEM_TASK_ABS_CPU', None)
+
+    if env_abscpu is not None:
+        return 0, int(env_abscpu)
+    elif settings_abscpu is not None:
+        return 0, int(settings_abscpu)
+
     cpu = psutil.cpu_count()
 
     if env_forkcpu:
@@ -661,6 +670,15 @@ def get_mem_capacity():
     from django.conf import settings
     settings_forkmem = getattr(settings, 'SYSTEM_TASK_FORKS_MEM', None)
     env_forkmem = os.getenv('SYSTEM_TASK_FORKS_MEM', None)
+
+    settings_absmem = getattr(settings, 'SYSTEM_TASK_ABS_MEM', None)
+    env_absmem = os.getenv('SYSTEM_TASK_ABS_MEM', None)
+
+    if env_absmem is not None:
+        return 0, int(env_absmem)
+    elif settings_absmem is not None:
+        return 0, int(settings_absmem)
+
     if env_forkmem:
         forkmem = int(env_forkmem)
     elif settings_forkmem: