Don't hardcode overcloud stack name.

When overcloud is deployed with other name than 'overcloud',
 credentials file(s) would reflect that.
E.g: when overcloud is called 'qe-cloud' credential files are:
  qe-cloudrc and qe-cloudrc.v3
This chage introduces new variable 'overcloud_stack_name'
 (default is 'overcloud') and adjusts paths to credentials files,
to be derived from stack's name.

Change-Id: I75dab2a85d94eb7fd012cd25a3e89720984c25e2

defaults/main.yml

@@ -3,6 +3,9 @@
 # main vars:
 working_dir: "{{ (ansible_env|default({})).HOME|default('/home/stack') }}"
 
+# overcloud stack name
+overcloud_stack_name: "overcloud"
+
 # TODO: those variable can be changed for the explicit keyword in tag
 # when https://github.com/ansible/ansible/issues/11045 is merged.
 
@@ -36,7 +39,7 @@ tripleo_ci: false
 
 #rc files:
 undercloud_rc: "{{ working_dir }}/stackrc"
-overcloud_rc: "{{ working_dir }}/overcloudrc"
+overcloud_rc: "{{ working_dir }}/{{ overcloud_stack_name }}rc"
 
 # launch workload before update/upgrade
 workload_launch: false

templates/workload_launch.sh.j2

@@ -2,7 +2,7 @@
 #
 # Script that spawns an instance
 
-OVERCLOUD_RC=~/overcloudrc
+OVERCLOUD_RC='{{ overcloud_rc }}'
 IMAGE_URL='{{ workload_image_url }}'
 IMAGE_NAME='upgrade_workload'
 IMAGE_FILE=~/upgrade_workload.qcow2