Heat template validation failed when multi users

[do-gyun kim]

...
Input task is invalid!

Subtask HeatStacks.create_and_delete_stack[0] has wrong configuration
Subtask configuration:
{"version": 2, "title": "A cropped version of a bigger task.", "description": "Auto-generated task from a single workload", "subtasks": [{"title": "HeatStacks.create_and_delete_stack", "description": "Create and then delete a stack.", "scenario": {"HeatStacks.create_and_delete_stack": {"template_path": "/tmp/tasks/test-templates/server-with-ports.yaml"}}, "contexts": {}, "runner": {"constant": {"concurrency": 2, "times": 3}}, "hooks": [], "sla": {"failure_rate": {"max": 0}}}]}

Reason(s):
 Scenario plugin 'HeatStacks.create_and_delete_stack' doesn't pass validate_heat_template@openstack validation. Details: Heat template validation failed on /tmp/tasks/test-templates/server-with-ports.yaml. Original error message: ERROR: Template not in valid format: Template format version not found..

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/rally-openstack/+/909566

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/rally-openstack/+/909566
Committed: https://opendev.org/openstack/rally-openstack/commit/2c05430515be6d253abbc3d5a8af7d28a5827409
Submitter: "Zuul (22348)"
Branch: master

commit 2c05430515be6d253abbc3d5a8af7d28a5827409
Author: do-gyun <email address hidden>
Date: Fri Feb 23 17:59:57 2024 +0900

    Fix heat template validation when multi users

    Fix that after the first user-related f.read(), the next user will attempt to f.read() at the end of the file, correcting the sending of blank content.

    Closes-bug: #2054790
    Change-Id: I95d73d3459087c8c18c1ecd5e7d1833268e7ed75