[BUGFIX] --custom-hostnames too long value

RHOSINFRA-1727: Ansible stat module fails when
value for --custom-hostnames is too long.

Change-Id: I40fa8ac86b2b2309823ced9b531fac031dccc4a2

Author: dktodorov

plugins/tripleo-overcloud/plugin.spec

@@ -448,7 +448,7 @@ subparsers:
                       help: |
                           Option to provide custom Hostnames for the nodes.
                           Note: Custom hostnames can be provided as values or a env file.
-                          Value example :
+                          Value example:
                           --custom-hostnames controller-0=ctr-rack-1-0,compute-0=compute-rack-2-0,ceph-0=ceph-rack-3-0
                           File example:
                           --custom-hostnames local/path/to/custom_hostnames.yaml

plugins/tripleo-overcloud/tasks/control_node_placement/custom_hostnames.yml

@@ -4,23 +4,27 @@
       path: "{{ install.custom.hostnames }}"
   register: custom_hostname_files
   delegate_to: localhost
+  when: install.custom.hostnames.split('/')[-1]|length <= 255
 
-- name: validate custom hostnames
-  fail:
-      msg: "{{ item }} is not valid value for --custom-hostnames"
-  when:
-      - not item.split('=')[1]|default(False)
-      - not custom_hostname_files.stat.exists
-  with_items: "{{ install.custom.hostnames.split(',') }}"
+- block:
+    - name: validate custom hostnames
+      fail:
+          msg: "{{ item }} is not valid value for --custom-hostnames"
+      when:
+          - not item.split('=')[1]|default(False)
+      with_items: "{{ install.custom.hostnames.split(',') }}"
 
-- name: create custom_hostnames.yaml
-  template:
-      src: control_node_placement/custom_hostnames.yaml.j2
-      dest: "{{ template_base }}/custom_hostnames.yaml"
-  when: not custom_hostname_files.stat.exists
+    - name: create custom_hostnames.yaml
+      template:
+          src: control_node_placement/custom_hostnames.yaml.j2
+          dest: "{{ template_base }}/custom_hostnames.yaml"
+
+  when: install.custom.hostnames.split('/')[-1]|length > 255 or not custom_hostname_files.stat.exists
 
 - name: copy provided env file for custom hostnames
   copy:
       src: "{{ install.custom.hostnames }}"
       dest: "{{ template_base }}/custom_hostnames.yaml"
-  when: custom_hostname_files.stat.exists
+  when:
+      - install.custom.hostnames.split('/')[-1]|length <= 255
+      - custom_hostname_files.stat.exists