Various fixes

• remove executions with fatal errors form the scheduling queue
• set services to error state when they fatally fail starting
• re-implement log streaming that was not working

zoe_api/rest_api/service.py

@@ -17,8 +17,8 @@
 
 import logging
 
-from tornado.web import RequestHandler, asynchronous
-import tornado.iostream
+from tornado.web import RequestHandler
+import tornado.gen
 
 from zoe_api.rest_api.utils import catch_exceptions, get_auth, manage_cors_headers
 from zoe_api.api_endpoint import APIEndpoint  # pylint: disable=unused-import
@@ -84,7 +84,6 @@ class ServiceLogsAPI(RequestHandler):
         self.finish()
 
     @catch_exceptions
-    @asynchronous
     def get(self, service_id):
         """HTTP GET method."""
 
@@ -92,13 +91,17 @@ class ServiceLogsAPI(RequestHandler):
 
         self.service_id = service_id
         self.log_obj = self.api_endpoint.service_logs(uid, role, service_id, stream=True)
-        self.stream = tornado.iostream.PipeIOStream(self.log_obj.fileno())
-        self.stream.read_until(b'\n', callback=self._stream_log_line)
-
-    def _stream_log_line(self, log_line):
-        self.write(log_line)
-        self.flush()
-        self.stream.read_until(b'\n', callback=self._stream_log_line)
+        self._stream_log_line()
+
+    @tornado.gen.coroutine
+    def _stream_log_line(self):
+        while True:
+            line = self.log_obj.read(4096)
+            if line is not None:
+                self.write(line)
+                self.flush()
+            else:
+                yield tornado.gen.sleep(0.2)
 
     def data_received(self, chunk):
         """Not implemented as we do not use stream uploads"""