Merge pull request #4 from aws-samples/CR_chkqueue

Commit chk q

Author: hi4rahul

README.md

@@ -12,7 +12,7 @@ This project contains source code and supporting files for a serverless applicat
 This application creates a serverless Amazon Rekognition Custom Label Detection workflow which runs on a pre-defined schedule (note that the schedule is enabled by default at deployment). It demonstrates the power of Step Functions to orchestrate Lambda functions and other AWS resources to form complex and robust workflows, coupled with event-driven development using Amazon EventBridge.
 
 Solution Architecture Diagram:
-<img width="814" alt="image" src="https://user-images.githubusercontent.com/34427009/102906604-c5c34e80-446c-11eb-918e-42dabbcacc93.png">
+<img width="814" alt="Architecture Diagram" src="docs/Solution%20Architecture%20-%20Serverless%20Computer%20Vision%20Label%20Detection.png">
 
 This application can also be used for creating a serverless image label inferencing pipeline for Amazon Lookout for Vision.
 

docs/Solution Architecture - Serverless Computer Vision Label Detection.png

@@ -22,49 +22,57 @@
 
 
 def lambda_handler(event, context):
-    
+
     lambda_client = boto3.client('lambda')
     try:
         uuid_response = lambda_client.list_event_source_mappings(
-            FunctionName = os.environ['analyze_lambda_arn']
-            )
+            FunctionName=os.environ['analyze_lambda_arn']
+        )
     except Exception as e:
-            print(e)
+        print(e)
 
     mylist = uuid_response['EventSourceMappings']
     uuiddata = mylist[0]['UUID']
     analyse_lambda_uuid = uuiddata
 
     try:
         response = lambda_client.get_event_source_mapping(
-            UUID = analyse_lambda_uuid
-            )
+            UUID=analyse_lambda_uuid
+        )
     except Exception as e:
-            print(e)
+        print(e)
 
     # State (string) -- The state of the event source mapping. It can be one of the following: Creating , Enabling , Enabled , Disabling , Disabled , Updating , or Deleting .
-    running_states = ["Enabling", "Enabled", "Disabled", "Disabling"]
-    if response['State'] in running_states:
-        # Disable
-        if (event[0]['Action'] == 'disable'): 
+    disabled_states = ["Disabled", "Disabling"]
+    enabled_states = ["Enabling", "Enabled"]
+    
+    # Disable
+    if (event[0]['Action'] == 'disable'):
+        if (response['State'] in disabled_states):
+            # Do Nothing
+            return 'Already disabled'
+        else:
             try:
                 response = lambda_client.update_event_source_mapping(
-                UUID = analyse_lambda_uuid,
-                    Enabled = False
+                    UUID=analyse_lambda_uuid,
+                    Enabled=False
                 )
             except Exception as e:
                 print(e)
-        else:
-            # Enable
-            if (event[0]['Action'] == 'enable'): 
+    else:
+        # Enable
+        if (event[0]['Action'] == 'enable'):
+            if (response['State'] in enabled_states):
+                # Do Nothing
+                return 'Already_Running'
+            else:
                 try:
                     response = lambda_client.update_event_source_mapping(
-                        UUID = analyse_lambda_uuid,
-                        Enabled = True
+                        UUID=analyse_lambda_uuid,
+                        Enabled=True
                     )
                 except Exception as e:
                     print(e)
-    else:
-        print("Current state is:", response['State'])
-
+    
+    print("Current state is:", response['State'])
     return response['State']

functions/toggle_trigger/app.py

@@ -12,7 +12,7 @@ Parameters:
 Mappings:
   Solution:
     Constants:
-      Version: "v0.7"
+      Version: "v0.8"
 
 Resources:
   SourceS3Bucket:
@@ -77,20 +77,20 @@ Resources:
     Type: AWS::Serverless::StateMachine
     Properties:
       Definition:
-        StartAt: Check Queue
+        StartAt: Check SQS Queue
         States:
-          Check Queue:
+          Check SQS Queue:
             Type: Task
             Resource: !GetAtt SQSPollerFunction.Arn
-            ResultPath: "$.messageinqueue"
-            Next: Choice State
-          Choice State:
+            ResultPath: $.messageinqueue
+            Next: Are there images to process?
+          Are there images to process?:
             Type: Choice
             Choices:
-              - Variable: "$.messageinqueue"
+              - Variable: $.messageinqueue
                 StringEquals: incoming
                 Next: Start Model
-            Default: Disable SQS Trigger
+            Default: Finish
           Start Model:
             Type: Task
             Resource: !GetAtt StartModelFunction.Arn
@@ -110,13 +110,33 @@ Resources:
           Keep Model running for 1 hr:
             Type: Wait
             Seconds: 3540
-            Next: Disable SQS Trigger
+            Next: Check Queue Again
+          Check Queue Again:
+            Type: Task
+            Resource: !GetAtt SQSPollerFunction.Arn
+            ResultPath: $.moremessagesinqueue
+            Next: Are there more images?
+          Are there more images?:
+            Type: Choice
+            Choices:
+              - Variable: $.moremessagesinqueue
+                StringEquals: stop
+                Next: Disable SQS Trigger
+            Default: Keep Model running for 1 hr
           Enable SQS Trigger:
             Type: Task
+            ResultPath: $.alreadyrunning
             Parameters:
               - Action: enable
             Resource: !GetAtt ToggleTriggerFunction.Arn
-            Next: Keep Model running for 1 hr
+            Next: Is another machine already running?
+          Is another machine already running?:
+            Type: Choice
+            Choices:
+                - Variable: $.alreadyrunning
+                  StringEquals: Already_Running
+                  Next: Finish
+            Default: Keep Model running for 1 hr
           Disable SQS Trigger:
             Type: Task
             Parameters:
@@ -126,7 +146,9 @@ Resources:
           Stop Model:
             Type: Task
             Resource: !GetAtt StopModelFunction.Arn
-            End: true
+            Next: Finish
+          Finish:
+            Type: Succeed
       Events:
         HourlyPollingSchedule:
           Type: Schedule # More info about Schedule Event Source: https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/sam-property-statemachine-schedule.html