Deprecate heat-all

It was added to be used in TripleO, which was already retired. Because
we do not expect any other use case in real deployments, deprecate it
so that we can remove it. The current implementation heavily relies on
the fact that we have wsgi server implementation, which is no longer
available once eventlet is removed.

Change-Id: I8c177b63350553a30c52d51b878a5a5473ccefb8

heat/cmd/all.py

@@ -22,6 +22,7 @@ import eventlet
 eventlet.monkey_patch(os=False)
 
 import sys
+import warnings
 
 from oslo_config import cfg
 import oslo_i18n as i18n
@@ -49,6 +50,9 @@ LAUNCH_SERVICES = {
 services_opt = cfg.ListOpt(
     'enabled_services',
     default=['engine', 'api', 'api_cfn'],
+    deprecated_for_removal=True,
+    deprecated_reason='The heat-all console script has been deprecated.',
+    deprecated_since='24.0.0',
     help='Specifies the heat services that are enabled when running heat-all. '
          'Valid options are all or any combination of '
          'api, engine or api_cfn.'
@@ -79,6 +83,9 @@ def launch_all(setup_logging=True):
 
 
 def main():
+    warnings.warn("The heat-all script has been deprecated and will be "
+                  "removed in the future.",
+                  DeprecationWarning)
     try:
         threads = launch_all()
         services = [thread.wait() for thread in threads]

releasenotes/notes/deprecate-heat-all-4d9abc588d8b1f7f.yaml

@@ -0,0 +1,5 @@
+---
+deprecations:
+  - |
+    The ``heat-all`` console script has been deprecated and will be removed
+    in a future release.