Add tags to roles

Prior to Ocata, the Controller role was hardcoded for various lookups.
When we switched to having the primary role name being dynamically
pulled from the roles_data.yaml using the first role as the primary
role as part of I36df7fa86c2ff40026d59f02248af529a4a81861, it
introduced a regression for folks who had previously been using
a custom roles file without the Controller being listed first.

Instead of relying on the position of the role in the roles data, this
change adds the concepts of tags to the role data that can be used when
looking for specific functionality within the deployment process. If
no roles are specified with this the tags indicating a 'primary'
'controller', it will fall back to using  the first role listed in the
roles data as the primary role.

Change-Id: Id3377e7d7dcc88ba9a61ca9ef1fb669949714f65
Closes-Bug: #1677374

5 files changed, 52 insertions, 7 deletions

diff --git a/docker/docker-steps.j2 b/docker/docker-steps.j2
index 301d838f..f0af8e25 100644
--- a/docker/docker-steps.j2
+++ b/docker/docker-steps.j2
@@ -1,7 +1,14 @@
 # certain initialization steps (run in a container) will occur
-# on the first role listed in the roles file
-{% set primary_role_name = roles[0].name -%}
-
+# on the role marked as primary controller or the first role listed
+{%- set primary_role = [roles[0]] -%}
+{%- for role in roles -%}
+  {%- if 'primary' in role.tags and 'controller' in role.tags -%}
+    {%- set _ = primary_role.pop() -%}
+    {%- set _ = primary_role.append(role) -%}
+  {%- endif -%}
+{%- endfor -%}
+{%- set primary_role_name = primary_role[0].name -%}
+# primary role is: {{primary_role_name}}
 heat_template_version: ocata
 
 description: >
diff --git a/overcloud.j2.yaml b/overcloud.j2.yaml
index a322a445..35cf7da8 100644
--- a/overcloud.j2.yaml
+++ b/overcloud.j2.yaml
@@ -1,4 +1,12 @@
-{% set primary_role_name = roles[0].name -%}
+{%- set primary_role = [roles[0]] -%}
+{%- for role in roles -%}
+  {%- if 'primary' in role.tags and 'controller' in role.tags -%}
+    {%- set _ = primary_role.pop() -%}
+    {%- set _ = primary_role.append(role) -%}
+  {%- endif -%}
+{%- endfor -%}
+{%- set primary_role_name = primary_role[0].name -%}
+# primary role is: {{primary_role_name}}
 heat_template_version: ocata
 
 description: >
diff --git a/releasenotes/notes/role-tags-16ac2e9e8fcab218.yaml b/releasenotes/notes/role-tags-16ac2e9e8fcab218.yaml
new file mode 100644
index 00000000..dadbfa4b
--- /dev/null
+++ b/releasenotes/notes/role-tags-16ac2e9e8fcab218.yaml
@@ -0,0 +1,18 @@
+---
+features:
+  - |
+    Adds tags to roles that allow an operator to specify custom tags to use
+    when trying to find functionality available from a role. Currently a role
+    with both the 'primary' and 'controller' tag is consider to be the primary
+    role.  Historically the role named 'Controller' was the 'primary' role and
+    this primary designation is used to determine items like memcache ip
+    addresses. If no roles have the both the 'primary' and 'controller' tags,
+    the first role specified in the roles_data.yaml is used as the primary
+    role.
+upgrade:
+  - |
+    If using custom roles data, the logic was changed to leverage the first
+    role listed in the roles_data.yaml file to be the primary role. This can
+    be worked around by adding the 'primary' and 'controller' tags to the
+    custom controller role in your roles_data.yaml to ensure that the defined
+    custom controller role is still considered the primary role.
diff --git a/roles_data.yaml b/roles_data.yaml
index 48859473..c35f49ee 100644
--- a/roles_data.yaml
+++ b/roles_data.yaml
@@ -28,9 +28,18 @@
 # ServicesDefault: (list) optional default list of services to be deployed
 # on the role, defaults to an empty list. Sets the default for the
 # {{role.name}}Services parameter in overcloud.yaml
-
-- name: Controller # the 'primary' role goes first
+#
+# tags: (list) list of tags used by other parts of the deployment process to
+# find the role for a specific type of functionality. Currently a role
+# with both 'primary' and 'controller' is used as the primary role for the
+# deployment process. If no roles have have 'primary' and 'controller', the
+# first role in this file is used as the primary role.
+#
+- name: Controller
   CountDefault: 1
+  tags:
+    - primary
+    - controller
   ServicesDefault:
     - OS::TripleO::Services::CACerts
     - OS::TripleO::Services::CertmongerUser
diff --git a/roles_data_undercloud.yaml b/roles_data_undercloud.yaml
index 8e830711..df2e196b 100644
--- a/roles_data_undercloud.yaml
+++ b/roles_data_undercloud.yaml
@@ -1,6 +1,9 @@
-- name: Undercloud # the 'primary' role goes first
+- name: Undercloud
   CountDefault: 1
   disable_constraints: True
+  tags:
+    - primary
+    - controller
   ServicesDefault:
     - OS::TripleO::Services::Ntp
     - OS::TripleO::Services::MySQL