Allow defaults for Image/Flavor/RoleParameters in roles_data.yaml

This allows specific roles, e.g ComputeRealTime to specify defaults
where the services are the same as some existing roles but a different
image and/or configuration are needed.

Inspired by discussion of this requirement in:
  https://review.openstack.org/#/c/531739/

RoleParametersDefaults is merged with the user provided parameters
with precendence to user parameters, as this is a special parameter,
which contains a map of the actual parameters to be applied to a
role.

Partially Implements: blueprint tripleo-realtime
Change-Id: I6497144340d3b9276e6ed141d3bc655bfbbeb53c

overcloud.j2.yaml

@@ -386,7 +386,10 @@ resources:
       EndpointMap: {get_attr: [EndpointMapData, value]}
       DefaultPasswords: {get_attr: [DefaultPasswords, passwords]}
       RoleName: {{role.name}}
-      RoleParameters: {get_param: {{role.name}}Parameters}
+      RoleParameters:
+        map_merge:
+          - {{role.RoleParametersDefault|default({})}}
+          - get_param: {{role.name}}Parameters
 
   # Lookup of role_data via heat outputs is slow, so workaround this by caching
   # the value in an OS::Heat::Value resource
@@ -564,7 +567,10 @@ resources:
           LoggingGroups: {get_attr: [{{role.name}}ServiceChainRoleData, value, logging_groups]}
           ServiceMetadataSettings: {get_attr: [{{role.name}}ServiceChainRoleData, value, service_metadata_settings]}
           DeploymentServerBlacklistDict: {get_attr: [DeploymentServerBlacklistDict, value]}
-          RoleParameters: {get_param: {{role.name}}Parameters}
+          RoleParameters:
+            map_merge:
+              - {{role.RoleParametersDefault|default({})}}
+              - get_param: {{role.name}}Parameters
 {% endfor %}
 
 {% for role in roles %}

puppet/role.role.j2.yaml

@@ -5,7 +5,7 @@
 heat_template_version: queens
 description: 'OpenStack {{role.name}} node configured by Puppet'
 parameters:
-{%- set default_flavor_name = 'baremetal' %}
+{%- set default_flavor_name = role.FlavorDefault|default('baremetal') %}
 {%- if role.deprecated_param_flavor is defined %}
   {{role.deprecated_param_flavor}}:
     description: DEPRECATED Use Overcloud{{role.name}}Flavor instead.
@@ -20,7 +20,7 @@ parameters:
     constraints:
       - custom_constraint: nova.flavor
 {%- endif %}
-{%- set default_image_name = 'overcloud-full' %}
+{%- set default_image_name = role.ImageDefault|default('overcloud-full') %}
 {%- if role.deprecated_param_image is defined %}
   {{role.deprecated_param_image}}:
     type: string
@@ -294,7 +294,7 @@ resources:
         get_param: {{role.name}}Image
 {%- endif %}
       image_update_policy: {get_param: ImageUpdatePolicy}
-      flavor: 
+      flavor:
 {%- if role.deprecated_param_flavor is defined %}
         if:
           - deprecated_param_flavor_set

roles/README.rst

@@ -34,6 +34,16 @@ Role Options
   defaults to '%stackname%-{{role.name.lower()}}-%index%'
   sets the default for {{role.name}}HostnameFormat parameter in overcloud.yaml
 
+* ImageDefault: (string) optional default image name or ID, defaults to
+  overcloud-full
+
+* FlavorDefault: (string) optional default flavor name or ID, defaults to
+  baremetal
+
+* RoleParametersDefault: (map) optional default to the per-role RoleParameters
+  value, this enables roles to specify specific values appropriate to their
+  configuration, defaults to an empty map.
+
 * disable_constraints: (boolean) optional, whether to disable Nova and Glance
   constraints for each role specified in the templates.