modified the heat charm to accomodate the workers-mutiplier option

Heat charm was missing this functionality and this patch is to add
this feature. We were trying to deploy this charm in a lxc
container on a host machine with 72 cores. In end up creating 144
process with heat-engine and heat-api.

This patch will provide the option to limit the number of worker
process in case of high number of cores in a host.

Enable it for icehouse, kilo, liberty and mitaka.

Change-Id: I811f0a91e1ff9a6d95e80a4a40be063d7d047c7e

config.yaml

@@ -217,4 +217,11 @@ options:
     description: |
       Apply system hardening. Supports a space-delimited list of modules
       to run. Supported modules currently include os, ssh, apache and mysql.
+  worker-multiplier:
+    type: float
+    default: 2.0
+    description: |
+      The CPU core multiplier to use when configuring worker processes for
+      Heat.  By default, the number of workers for each daemon is set to
+      twice the number of CPU cores a service unit has.
 

hooks/heat_utils.py

@@ -101,6 +101,7 @@ CONFIG_FILES = OrderedDict([
                      InstanceUserContext(),
                      context.SyslogContext(),
                      context.LogLevelContext(),
+                     context.WorkerConfigContext(),
                      context.BindHostContext()]
     }),
     (HEAT_API_PASTE, {

templates/icehouse/heat.conf

@@ -12,6 +12,7 @@ environment_dir=/etc/heat/environment.d
 deferred_auth_method=password
 host=heat
 auth_encryption_key={{ encryption_key }}
+num_engine_workers = {{ workers }}
 
 {% if database_host -%}
 # < Icehouse db config
@@ -70,6 +71,7 @@ bind_port={{ api_listen_port }}
 {% else -%}
 bind_port=8004
 {% endif %}
+workers = {{ workers }}
 
 [heat_api_cfn]
 {% if api_cfn_listen_port -%}
@@ -77,3 +79,4 @@ bind_port={{ api_cfn_listen_port }}
 {% else -%}
 bind_port=8000
 {% endif %}
+workers = {{ workers }}

templates/kilo/heat.conf

@@ -13,6 +13,7 @@ deferred_auth_method = trusts
 stack_domain_admin = heat_domain_admin
 stack_domain_admin_password = {{ heat_domain_admin_passwd }}
 stack_user_domain_name = heat
+num_engine_workers = {{ workers }}
 
 {% if auth_host -%}
 [keystone_authtoken]
@@ -43,6 +44,7 @@ bind_port={{ api_listen_port }}
 {% else -%}
 bind_port=8004
 {% endif %}
+workers = {{ workers }}
 
 [heat_api_cfn]
 bind_host = {{ bind_host }}
@@ -51,6 +53,7 @@ bind_port={{ api_cfn_listen_port }}
 {% else -%}
 bind_port=8000
 {% endif %}
+workers = {{ workers }}
 
 {% include "section-rabbitmq-oslo" %}
 

templates/liberty/heat.conf

@@ -13,6 +13,7 @@ deferred_auth_method = trusts
 stack_domain_admin = heat_domain_admin
 stack_domain_admin_password = {{ heat_domain_admin_passwd }}
 stack_user_domain_name = heat
+num_engine_workers = {{ workers }}
 
 {% if auth_host -%}
 [keystone_authtoken]
@@ -56,6 +57,7 @@ bind_port={{ api_listen_port }}
 {% else -%}
 bind_port=8004
 {% endif %}
+workers = {{ workers }}
 
 [heat_api_cfn]
 bind_host = {{ bind_host }}
@@ -64,6 +66,7 @@ bind_port={{ api_cfn_listen_port }}
 {% else -%}
 bind_port=8000
 {% endif %}
+workers = {{ workers }}
 
 {% include "section-rabbitmq-oslo" %}
 

templates/mitaka/heat.conf

@@ -13,6 +13,7 @@ deferred_auth_method = trusts
 stack_domain_admin = heat_domain_admin
 stack_domain_admin_password = {{ heat_domain_admin_passwd }}
 stack_user_domain_name = heat
+num_engine_workers = {{ workers }}
 
 {% if auth_host -%}
 {% include "section-keystone-authtoken-mitaka" %}
@@ -47,6 +48,7 @@ bind_port={{ api_listen_port }}
 {% else -%}
 bind_port=8004
 {% endif %}
+workers = {{ workers }}
 
 [heat_api_cfn]
 bind_host = {{ bind_host }}
@@ -55,6 +57,7 @@ bind_port={{ api_cfn_listen_port }}
 {% else -%}
 bind_port=8000
 {% endif %}
+workers = {{ workers }}
 
 {% include "section-rabbitmq-oslo" %}