added first version of an HTTP REST API

Author: stv0g

requirements.txt

@@ -7,3 +7,4 @@ kubernetes
 xdg
 dotmap
 PyYAML
+tornado

setup.py

@@ -31,7 +31,8 @@
         'villas-node>=0.10.2',
         'kubernetes',
         'xdg',
-        'PyYAML'
+        'PyYAML',
+        'tornado'
     ],
     data_files=[
         ('/etc/villas/controller', glob('etc/*.{json,yaml}')),

villas/controller/api.py

@@ -0,0 +1,54 @@
+import threading
+import logging
+import asyncio
+from tornado.ioloop import IOLoop
+import tornado.web
+
+LOGGER = logging.getLogger(__name__)
+REGEX_UUID = r'\b[0-9a-fA-F]{8}\b-[0-9a-fA-F]{4}-[0-9a-fA-F]' \
+             r'{4}-[0-9a-fA-F]{4}-\b[0-9a-fA-F]{12}\b'
+
+
+class RequestHandler(tornado.web.RequestHandler):
+
+    def initialize(self, controller):
+        self.controller = controller
+
+
+class Api(threading.Thread):
+
+    def __init__(self, controller):
+        super().__init__()
+
+        self.controller = controller
+
+    def run(self):
+        self.app = tornado.web.Application(self.handlers)
+
+        # Create new event loop for this thread
+        aio_loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(aio_loop)
+
+        port = self.controller.config.api.port
+        self.app.listen(port)
+
+        LOGGER.info('Starting API')
+
+        self.loop = IOLoop.current(instance=True)
+        self.loop.start()
+
+    @property
+    def handlers(self):
+        from villas.controller.handlers.component import ComponentRequestHandler  # noqa E501
+        from villas.controller.handlers.main import MainRequestHandler
+        from villas.controller.handlers.health import HealthRequestHandler
+
+        args = {
+            'controller': self.controller
+        }
+
+        return [
+            (r'/', MainRequestHandler, args),
+            (r'/health', HealthRequestHandler, args),
+            (r'/component/('+REGEX_UUID+r')', ComponentRequestHandler, args)
+        ]

villas/controller/component.py

@@ -112,7 +112,10 @@ def on_message(self, message):
         self.logger.debug('Received message: %s', message.payload)
 
         if 'action' in message.payload:
-            self.run_action(message.payload['action'], message.payload)
+            try:
+                self.run_action(message.payload['action'], message.payload)
+            except SimulationException:
+                pass
 
         message.ack()
 
@@ -151,6 +154,8 @@ def run_action(self, action, payload):
             self.logger.error('SimulationException: %s', str(se))
             self.change_state('error', msg=se.msg, **se.info)
 
+            raise se
+
     def change_state(self, state, **kwargs):
         if self._state == state:
             return

villas/controller/controller.py

@@ -5,6 +5,7 @@
 import os
 import kombu.mixins
 
+from villas.controller.api import Api
 from villas.controller import __version__ as version
 from villas.controller.components.managers.generic import GenericManager
 
@@ -110,6 +111,11 @@ def on_iteration(self):
 
     def start(self):
         self.started = time.time()
+
+        if self.config.api.enabled:
+            self.api = Api(self)
+            self.api.start()
+
         self.should_terminate = False
         while not self.should_terminate:
             self.should_stop = False

villas/controller/handlers/component.py

@@ -0,0 +1,51 @@
+import json
+from tornado.web import HTTPError
+from http import HTTPStatus
+from functools import wraps
+
+
+from villas.controller.api import RequestHandler
+from villas.controller.exceptions import SimulationException
+
+
+def with_component(f):
+
+    @wraps(f)
+    def wrapper(self, uuid):
+        try:
+            component = self.controller.components[uuid]
+
+            f(self, component)
+        except KeyError:
+            raise HTTPError(HTTPStatus.NOT_FOUND)
+
+    return wrapper
+
+
+class ComponentRequestHandler(RequestHandler):
+
+    @with_component
+    def get(self, component):
+        self.write(component.status)
+
+    @with_component
+    def post(self, component):
+        payload = json.loads(self.request.body)
+
+        action = payload.get('action')
+        if action is None:
+            raise HTTPError(HTTPStatus.BAD_REQUEST)
+
+        try:
+            component.run_action(action, payload)
+            self.write(component.status)
+
+        except SimulationException as se:
+            self.write({
+                'exception': {
+                    'msg': se.msg,
+                    'args': se.args
+                },
+                **component.status
+            })
+            self.send_error(HTTPStatus.BAD_REQUEST)

villas/controller/handlers/health.py

@@ -0,0 +1,9 @@
+from villas.controller.api import RequestHandler
+
+
+class HealthRequestHandler(RequestHandler):
+
+    def get(self):
+        self.write({
+            'status': 'ok'
+        })

villas/controller/handlers/main.py

@@ -0,0 +1,12 @@
+from villas.controller.api import RequestHandler
+
+
+class MainRequestHandler(RequestHandler):
+
+    def get(self):
+        self.write({
+            'components': list(self.controller.components.keys()),
+            'status': {
+                **self.controller.status
+            }
+        })