Select first node as bootstrap node not using name

This fixes a regression which reintroduced bug #1640449 because
we hard-code the node index/name instead of sorting the map of servers

Change-Id: Iaffc66a41edf176dde3b5adf603a9cff6db7aa24
Closes-Bug: #1724888

common/deploy-steps.j2

@@ -188,6 +188,14 @@ resources:
 # END workflow_tasks handling
 {% endfor %}
 
+  BootstrapServerId:
+    type: OS::Heat::Value
+    properties:
+      value:
+        yaql:
+          expression: $.data.items().orderBy($[0]).first()[1]
+          data: {get_param: [servers, {{primary_role_name}}]}
+
 # Artifacts config and HostPrepConfig is done on all roles, not only
 # enabled_roles, because on upgrade we need to write the json files
 # for the operator driven upgrade scripts (the ansible steps consume them)
@@ -222,7 +230,7 @@ resources:
                   docker_puppet_tasks: {get_param: [role_data, {{role.name}}, docker_puppet_tasks]}
                   docker_startup_configs: {get_param: [role_data, {{role.name}}, docker_config]}
                   kolla_config: {get_param: [role_data, {{role.name}}, kolla_config]}
-                  bootstrap_server_id: {get_param: [servers, {{primary_role_name}}, '0']}
+                  bootstrap_server_id: {get_attr: [BootstrapServerId, value]}
                   puppet_step_config: {get_param: [role_data, {{role.name}}, step_config]}
                   docker_config_scripts: {get_param: [role_data, {{role.name}}, docker_config_scripts]}
                 tasks:
@@ -330,7 +338,7 @@ resources:
         step: {{step}}
         role_name: {{role.name}}
         update_identifier: {get_param: DeployIdentifier}
-        bootstrap_server_id: {get_param: [servers, {{primary_role_name}}, '0']}
+        bootstrap_server_id: {get_attr: [BootstrapServerId, value]}
         enable_debug: {get_param: ConfigDebug}
         docker_puppet_debug: {get_param: DockerPuppetDebug}
         docker_puppet_process_count: {get_param: DockerPuppetProcessCount}
@@ -374,7 +382,7 @@ outputs:
       deploy_steps_playbook:
         str_replace:
           params:
-            BOOTSTRAP_SERVER_ID: {get_param: [servers, {{primary_role_name}}, '0']}
+            BOOTSTRAP_SERVER_ID: {get_attr: [BootstrapServerId, value]}
           template: |
             - hosts: undercloud
               name: Gather facts undercloud