cloudwatchevent_rule default to latest version of lambda function - amazon-web-services

Question

I am trying to automate the creation of a lambda function and cloudwatch rule for it. However it seems that the cloudwatchevent_rule ansible task requires a version id to attach itself to my lambda function. This is causing an error:
No target to arn:aws:lambda:us-east-
1:MYACCOUNTID:function:MYFUNCTIONNAME could be found on the rule
MYFUNCTIONNAME.
How can I change this so that the cloudwatch rule will always attach itself to the latest version of my lambda function:
- name: create cloudwatch rule
cloudwatchevent_rule:
name: 'name_for_rule'
region: "{{region}}"
description: 'trigger on new instance creation'
state: present
event_pattern: |-
{
"detail-type": [
"AWS API Call via CloudTrail"
],
"detail": {
"eventSource": [
"ec2.amazonaws.com"
],
"eventName": [
"RunInstances"
]
}
}
targets:
- id: "{{ lambda.configuration.version }}"
arn: "{{ lambda.configuration.function_arn }}"

Answer 1

I've configured a Lambda Function with CloudWatch rule triggering it. The following SAM Template also contains permission, policy and roles I require. Please ignore those if not required.
{
"AWSTemplateFormatVersion": "2010-09-09",
"Transform": "AWS::Serverless-2016-10-31",
"Description": "AWS SAM template configuring lambda functions written in test package.",
"Resources": {
"OrchestratorTestLambdaFunction": {
"DependsOn": [
"LambdaPolicy"
],
"Type": "AWS::Lambda::Function",
"Properties": {
"Handler": "com.test.TestClass::orchestrateTestLambda",
"FunctionName": "OrchestratorTestLambda",
"Runtime": "java8",
"MemorySize": 256,
"Timeout": 60,
"Code": {
"S3Bucket": "BATS::SAM::CodeS3Bucket",
"S3Key": "BATS::SAM::CodeS3Key"
},
"Role": {
"Fn::GetAtt": [
"LambdaRole",
"Arn"
]
},
"Description": "Lambda reads from SQS provided in the cloud watch."
}
},
"LambdaRole": {
"Type": "AWS::IAM::Role",
"Properties": {
"RoleName": "LambdaRole",
"AssumeRolePolicyDocument": {
"Version": "2008-10-17",
"Statement": [
{
"Sid": "",
"Effect": "Allow",
"Principal": {
"Service": "lambda.amazonaws.com"
},
"Action": "sts:AssumeRole"
}
]
}
}
},
"LambdaPolicy": {
"Type": "AWS::IAM::Policy",
"Properties": {
"PolicyName": "lambda_policy",
"PolicyDocument": {
"Version": "2012-10-17",
"Statement": [
{
"Sid": "",
"Effect": "Allow",
"Action": [
"sqs:DeleteMessage",
"sqs:ReceiveMessage"
],
"Resource": [
{
"Fn::Sub": "arn:aws:sqs:eu-west-1:${AWS::AccountId}:TestUpdates"
}
]
},
{
"Sid": "",
"Action": [
"lambda:InvokeAsync"
],
"Effect": "Allow",
"Resource": "*"
},
{
"Sid": "",
"Effect": "Allow",
"Action": [
"logs:CreateLogGroup",
"logs:CreateLogStream",
"logs:PutLogEvents"
],
"Resource": "arn:aws:logs:*:*:*"
}
]
},
"Roles": [
{
"Ref": "LambdaRole"
}
]
}
},
"PermissionForEventsToInvokeLambda": {
"Type": "AWS::Lambda::Permission",
"Properties": {
"FunctionName": {
"Ref": "OrchestratorTestLambdaFunction"
},
"Action": "lambda:InvokeFunction",
"Principal": "events.amazonaws.com",
"SourceArn": {
"Fn::GetAtt": [
"TestRule",
"Arn"
]
}
}
},
"TestRule": {
"Type": "AWS::Events::Rule",
"Properties": {
"Name": "TestRule",
"Description": "Rule to Trigger OrchestratorTestLambdaFunction",
"ScheduleExpression": "rate(1 minute)",
"State": "ENABLED",
"Targets": [
{
"Arn": {
"Fn::GetAtt": [
"OrchestratorTestLambdaFunction",
"Arn"
]
},
"Id": "TestRuleV1",
"Input": {
"Fn::Sub": "{\"queueUrl\":\"https://sqs.eu-west-1.amazonaws.com/${AWS::AccountId}/TestUpdates\"}"
}
}
]
}
}
},
"Outputs": {
"StackArn": {
"Value": {
"Ref": "AWS::StackId"
},
"Description": "Use this as the stack_arn in your cloud_formation_deployment_stack override."
}
}
}

Answer 2

I've noticied that function_arn registered from lambda ansible module output is not consistent.
Some times is
"function_arn": "arn:aws:lambda:zone:account:function:name"
other time is:
"function_arn": "arn:aws:lambda:zone:account:function:name:version"
So I've construct the arn appending always the $LATEST version:
- cloudwatchevent_rule:
profile: "{{ aws_profile }}"
name: StartStop
schedule_expression: cron(* * * * ? *)
description: trigger my lambda
targets:
- id: StartStop
arn: "arn:aws:lambda:{{aws_zone}}:{{aws_account_id}}:function:{{lambdadeploy.configuration.function_name}}:$LATEST"