Change for synchronous Mistral actions from CLI

This patch allows the Mistral actions to be run synchronously from
the Mistral CLI.

When a Mistral action is run synchronously using the Mistral CLI
'run-action' command, it does not complete successfully. This is due
to the Mistral API server handling requests on a single thread.

The 'run-action' command performs a REST POST call to the
ActionExecution RestController in the API server. That in turn calls
back into the python-mistralclient which then performs another REST
call back to the appropriate REST controller to actually run the
action requested. That call hangs since the requests are handled on
a single thread because the first POST has not completed yet.
Eventually the RPC call between the engine and the executor servers
times out, and the 'run-action' command fails.

This patch changes the Mistral API server so that requests are
handled in separate threads.

Added a new functional test to the tempest test package to test
synchronous action execution of a mistral action from within
mistral.

Change-Id: I8e06d3ef6aab4b2009a8fff4aa4d1acc118eee3f
Implements: blueprint mistral-mistral-actions

mistral/cmd/launch.py

@@ -25,6 +25,7 @@ eventlet.monkey_patch(
     time=True)
 
 import os
+import six
 import time
 
 # If ../mistral/__init__.py exists, add ../ to Python search path, so that
@@ -38,7 +39,14 @@ if os.path.exists(os.path.join(POSSIBLE_TOPDIR, 'mistral', '__init__.py')):
 from oslo_config import cfg
 from oslo_log import log as logging
 import oslo_messaging as messaging
+
+if six.PY3 is True:
+    import socketserver
+else:
+    import SocketServer as socketserver
+
 from wsgiref import simple_server
+from wsgiref.simple_server import WSGIServer
 
 from mistral.api import app
 from mistral import config
@@ -128,6 +136,10 @@ def launch_engine(transport):
         server.wait()
 
 
+class ThreadingWSGIServer(socketserver.ThreadingMixIn, WSGIServer):
+    pass
+
+
 def launch_api(transport):
     host = cfg.CONF.api.host
     port = cfg.CONF.api.port
@@ -135,7 +147,8 @@ def launch_api(transport):
     server = simple_server.make_server(
         host,
         port,
-        app.setup_app()
+        app.setup_app(),
+        ThreadingWSGIServer
     )
 
     LOG.info("Mistral API is serving on http://%s:%s (PID=%s)" %

mistral_tempest_tests/tests/api/v2/test_mistral_basic_v2.py

@@ -1167,3 +1167,18 @@ class ActionExecutionTestsV2(base.TestCase):
             'action_executions',
             'nonexist'
         )
+
+    @test.attr(type='sanity')
+    def test_create_action_execution_sync(self):
+        token = self.client.auth_provider.get_token()
+        resp, body = self.client.create_action_execution(
+            {
+                'name': 'std.http',
+                'input': '{{"url": "http://localhost:8989/v2/workflows",\
+                           "headers": {{"X-Auth-Token": "{}"}}}}'.format(token)
+            }
+        )
+
+        self.assertEqual(201, resp.status)
+        output = json.loads(body['output'])
+        self.assertEqual(200, output['result']['status'])