Add stacks related to dispatch Lambda

config/develop/namespaced/lambda-dispatch-role.yaml

@@ -0,0 +1,11 @@
+template:
+  path: lambda-dispatch-role.yaml
+stack_name: "{{ stack_group_config.namespace }}-lambda-dispatch-role"
+dependencies:
+  - develop/namespaced/sqs-input-to-dispatch.yaml
+parameters:
+  SQSQueueArn: !stack_output_external "{{ stack_group_config.namespace }}-sqs-input-to-dispatch::PrimaryQueueArn"
+  S3SourceBucketName: {{ stack_group_config.input_bucket_name }}
+  SNSTopicArn: !stack_output_external "{{ stack_group_config.namespace }}-sns-dispatch::SnsTopicArn"
+stack_tags:
+  {{ stack_group_config.default_stack_tags }}

config/develop/namespaced/lambda-dispatch.yaml

@@ -0,0 +1,15 @@
+template:
+  type: sam
+  path: src/lambda_function/dispatch/template.yaml
+  artifact_bucket_name: {{ stack_group_config.template_bucket_name }}
+  artifact_prefix: "{{ stack_group_config.namespace }}/src/lambda"
+dependencies:
+  - develop/namespaced/lambda-dispatch-role.yaml
+  - develop/namespaced/sqs-input-to-dispatch.yaml
+  - develop/s3-cloudformation-bucket.yaml
+stack_name: "{{ stack_group_config.namespace }}-lambda-dispatch"
+stack_tags: {{ stack_group_config.default_stack_tags }}
+parameters:
+  RoleArn: !stack_output_external "{{ stack_group_config.namespace }}-lambda-dispatch-role::RoleArn"
+  SQSQueueArn: !stack_output_external "{{ stack_group_config.namespace }}-sqs-input-to-dispatch::PrimaryQueueArn"
+  DispatchSnsArn: !stack_output_external "{{ stack_group_config.namespace }}-sns-dispatch::SnsTopicArn"

config/develop/namespaced/sns-dispatch.yaml

@@ -0,0 +1,9 @@
+template:
+  path: sns-topic.yaml
+dependencies:
+  - develop/namespaced/lambda-dispatch.yaml
+parameters:
+  LambdaSourceArn: !stack_output_external "{{ stack_group_config.namespace }}-lambda-dispatch::DispatchFunctionArn"
+stack_name: "{{ stack_group_config.namespace }}-sns-dispatch"
+stack_tags:
+  {{ stack_group_config.default_stack_tags }}

config/develop/namespaced/sqs-input-to-dispatch.yaml

@@ -7,6 +7,6 @@ parameters:
   SNSTopicSubscription: !stack_output_external "{{ stack_group_config.namespace }}-sns-input::SnsTopicArn"
 dependencies:
   - develop/namespaced/sns-input.yaml
-stack_name: '{{ stack_group_config.namespace }}-sqs-input-to-dispatch'
+stack_name: "{{ stack_group_config.namespace }}-sqs-input-to-dispatch"
 stack_tags:
   {{ stack_group_config.default_stack_tags }}

src/lambda_function/dispatch/README.md

@@ -48,4 +48,3 @@ sam local invoke
 ## Launching Lambda stack in AWS
 
 There are two stacks relevant to this Lambda: `dispatch-lambda` and `dispatch-lambda-role`.
-

templates/lambda-dispatch-role.yaml

@@ -0,0 +1,78 @@
+AWSTemplateFormatVersion: '2010-09-09'
+
+Transform: AWS::Serverless-2016-10-31
+
+Description: >
+  An IAM Role for the dispatch lambda
+
+Parameters:
+  SQSQueueArn:
+    Type: String
+    Description: ARN of the SQS queue for lambda to poll messages from.
+
+  S3SourceBucketName:
+    Type: String
+    Description: Name of the S3 bucket where exports are deposited.
+
+  SNSTopicArn:
+    Type: String
+    Description: ARN of the SNS topic which dispatched jobs will be published to.
+
+Resources:
+  DispatchRole:
+      Type: AWS::IAM::Role
+      Properties:
+        AssumeRolePolicyDocument:
+          Version: '2012-10-17'
+          Statement:
+          - Effect: Allow
+            Principal:
+              Service:
+              - lambda.amazonaws.com
+            Action:
+            - sts:AssumeRole
+        ManagedPolicyArns:
+          - arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole
+        Policies:
+        - PolicyName: PollSQSQueue
+          PolicyDocument:
+            Version: '2012-10-17'
+            Statement:
+            - Effect: Allow
+              Action:
+              - sqs:DeleteMessage
+              - sqs:GetQueueAttributes
+              - sqs:ReceiveMessage
+              Resource:
+              - !Ref SQSQueueArn
+        - PolicyName: ReadS3
+          PolicyDocument:
+            Version: '2012-10-17'
+            Statement:
+            - Effect: Allow
+              Action:
+              - s3:Get*
+              - s3:List*
+              Resource:
+              - !Sub arn:aws:s3:::${S3SourceBucketName}
+              - !Sub arn:aws:s3:::${S3SourceBucketName}/*
+        - PolicyName: PublishToSNS
+          PolicyDocument:
+            Version: '2012-10-17'
+            Statement:
+              - Effect: Allow
+                Action:
+                  - sns:Publish
+                Resource:
+                  - !Ref SNSTopicArn
+
+Outputs:
+  RoleName:
+    Value: !Ref DispatchRole
+    Export:
+      Name: !Sub '${AWS::Region}-${AWS::StackName}-RoleName'
+
+  RoleArn:
+    Value: !GetAtt DispatchRole.Arn
+    Export:
+      Name: !Sub '${AWS::Region}-${AWS::StackName}-RoleArn'

templates/sns-topic.yaml

@@ -1,13 +1,29 @@
 AWSTemplateFormatVersion: "2010-09-09"
 
 Description: >
-  Creates a Standard SNS queue which can be used with S3 event notifications.
+  Creates a Standard SNS queue which can be used with S3 event notifications or Lambda triggers.
 
 Parameters:
 
   S3SourceBucketArn:
     Type: String
-    Description: Arn of the S3 bucket where source data are stored.
+    Default: ""
+    Description: >
+      ARN of an S3 bucket where source data are stored. Specifying this
+      parameter enables this SNS topic to have S3 event notifications published to it.
+
+  LambdaSourceArn:
+    Type: String
+    Default: ""
+    Description: ARN of the Lambda function which can trigger this SNS topic. Specifying this
+      parameter enables this SNS topic to have a Lambda publish to it.
+
+Conditions:
+  HasS3SourceBucketArn:
+    !Not [!Equals [!Ref S3SourceBucketArn, ""]]
+
+  HasLambdaSourceArn:
+    !Not [!Equals [!Ref LambdaSourceArn, ""]]
 
 Resources:
 
@@ -17,8 +33,9 @@ Resources:
       TopicName: !Sub "${AWS::StackName}-Topic"
       FifoTopic: false
 
-  SnsTopicPolicy:
+  SnsTopicPolicyForS3:
     Type: AWS::SNS::TopicPolicy
+    Condition: HasS3SourceBucketArn
     Properties:
       PolicyDocument:
         Version: "2012-10-17"
@@ -27,16 +44,35 @@ Resources:
             Effect: Allow
             Principal:
               Service: s3.amazonaws.com
-              AWS: !Sub '${AWS::AccountId}'
             Action:
-            - sns:Publish
+              - sns:Publish
             Resource: !Ref SnsTopic
             Condition:
               ArnLike:
                 "aws:SourceArn": !Ref S3SourceBucketArn
       Topics:
         - !Ref SnsTopic
 
+  SnsTopicPolicyForLambda:
+    Type: AWS::SNS::TopicPolicy
+    Condition: HasLambdaSourceArn
+    Properties:
+      PolicyDocument:
+        Version: "2012-10-17"
+        Statement:
+          - Sid: Lambda trigger to SNS
+            Effect: Allow
+            Principal:
+              Service: lambda.amazonaws.com
+            Action:
+              - sns:Publish
+            Resource: !Ref SnsTopic
+            Condition:
+              ArnLike:
+                "aws:SourceArn": !Ref LambdaSourceArn
+      Topics:
+        - !Ref SnsTopic
+
 Outputs:
 
   SnsTopicArn:

tests/test_lambda_dispatch.py

@@ -173,5 +173,3 @@ def test_main(event, temp_zip_file, s3_event, archive_path):
                 temp_zip_path=temp_zip_file.name
         )
         mock_publish.assert_called()
-
-