diff --git a/Web/Python/launcher.py b/Web/Python/launcher.py
index 9d3916d98bad26b055aa0ec53cb6530c59950af8..738b79da470fe9e007662936f085cdb0dcb81a58 100755
--- a/Web/Python/launcher.py
+++ b/Web/Python/launcher.py
@@ -13,6 +13,7 @@ from random import choice
from twisted.internet import reactor, defer
from twisted.internet.task import deferLater
+from twisted.internet.defer import CancelledError
from twisted.python import log
from twisted.web import server, resource, http
from twisted.web.resource import Resource
@@ -282,11 +283,14 @@ class ProcessManager(object):
for id in self.processes:
self.processes[id].terminate()
- def startProcess(self, session, ready_callback=None):
+ def _getLogFilePath(self, id):
+ return "%s%s%s.txt" % (self.log_dir, os.sep, id)
+
+ def startProcess(self, session):
proc = None
# Create output log file
- logFilePath = self.log_dir + os.sep + str(session['id']) + ".txt"
+ logFilePath = self._getLogFilePath(session['id'])
with open(logFilePath, "a+") as log_file:
try:
proc = subprocess.Popen(session['cmd'], stdout=log_file, stderr=log_file)
@@ -316,6 +320,38 @@ class ProcessManager(object):
def isRunning(self, id):
return self.processes[id].poll() is None
+ # ========================================================================
+ # Look for ready line in process output. Return True if found, False
+ # otherwise. If no ready_line is configured and process is running return
+ # True.
+ # ========================================================================
+
+ def isReady(self, session):
+ id = session['id']
+
+ # The process has to be running to be ready!
+ if not self.isRunning(id):
+ return False
+
+ application = self.config['apps'][session['application']]
+ ready_line = application.get('ready_line', None)
+
+ # If no ready_line is configured and the process is running then thats
+ # enough.
+ if not ready_line:
+ return True
+
+ ready = False
+
+ # Check the output for ready_line
+ logFilePath = self._getLogFilePath(session['id'])
+ with open(logFilePath, "r") as log_file:
+ for line in log_file.readlines():
+ if ready_line in line:
+ ready = True
+ break
+
+ return ready
# ===========================================================================
# Class to implement requests to POST, GET and DELETE methods
@@ -361,29 +397,81 @@ class LauncherResource(resource.Resource, object):
if not session:
return json.dumps({"error": "All the resources are currently taken"})
- # Create response callback
- d = deferLater(reactor, self.time_to_wait, lambda: request)
- d.addCallback(self._delayedRender, session_id=session['id'])
-
# Start process
- proc = self.process_manager.startProcess(session, d)
+ proc = self.process_manager.startProcess(session)
if not proc:
- request.setResponseCode(http.OK)
+ request.setResponseCode(http.SERVICE_UNAVAILABLE)
return json.dumps({"error": "The process did not properly start. %s" % str(session['cmd'])})
+ # local function to act as errback for Deferred objects.
+ def errback(error):
+ # Filter out CancelledError and propagate rest
+ if error.type != CancelledError:
+ return error
+
+ # Deferred object set to timeout request if process doesn't start in time
+ timeout_deferred = deferLater(reactor, self.time_to_wait, lambda: request)
+ timeout_deferred.addCallback(self._delayedRenderTimeout, session)
+ timeout_deferred.addErrback(errback)
+ # Make sure other deferred is canceled once one has been fired
+ request.notifyFinish().addCallback(lambda x: timeout_deferred.cancel())
+
+ # If a ready_line is configured create a Deferred object to wait for
+ # ready line to be produced
+ if 'ready_line' in self._config['apps'][session['application']]:
+ ready_deferred = self._waitForReady(session, request)
+ ready_deferred.addCallback(self._delayedRenderReady, session)
+ ready_deferred.addErrback(errback)
+ # Make sure other deferred is canceled once one has been fired
+ request.notifyFinish().addCallback(lambda x: ready_deferred.cancel())
+
return NOT_DONE_YET
- def _delayedRender(self, request, session_id=None):
- session = self.session_manager.getSession(session_id)
- running = self.process_manager.isRunning(session_id)
- if session and running:
+ # ========================================================================
+ # Wait for session to be ready. Rather than blocking keep using callLater(...)
+ # to schedule self in reactor. Return a Deferred object whose callback will
+ # be triggered when the session is ready
+ # ========================================================================
+
+ def _waitForReady(self, session, request, d=None):
+ if not d:
+ d = defer.Deferred()
+
+ if not self.process_manager.isReady(session):
+ reactor.callLater(1, self._waitForReady, session, request, d)
+ else:
+ d.callback(request)
+
+ return d
+
+ # ========================================================================
+ # Called when the timeout out expires. Check if process is now ready
+ # and send response to client.
+ # ========================================================================
+
+ def _delayedRenderTimeout(self, request, session):
+ ready = self.process_manager.isReady(session)
+
+ if ready:
request.write(json.dumps(filterResponse(session, self.field_filter)))
+ request.setResponseCode(http.OK)
else:
- request.write(json.dumps({"error":"Session did not properly started"}))
+ request.write(json.dumps({"error": "Session did not start before timeout expired. Check session logs."}))
+ request.setResponseCode(http.SERVICE_UNAVAILABLE)
+
+ request.finish()
+ # ========================================================================
+ # Called when the process is ready ( the ready line has been read from the
+ # process output).
+ # ========================================================================
+
+ def _delayedRenderReady(self, request, session):
+ request.write(json.dumps(filterResponse(session, self.field_filter)))
request.setResponseCode(http.OK)
+
request.finish()
# =========================================================================