I have a lambda function which is triggered by an Eventbridge rule. When I delete that Eventbridge rule, the trigger still appears in the lambda console.
screenshot of lambda console, under configuration tab
Is there any api or sdk method like deleteTrigger or something?
However aws internally call this post method https://ap-south-1.console.aws.amazon.com/lambda/services/ajax?operation=deleteRelation&locale=en
Related
I have a question regarding the relationship between Lambda functions and Amazon SNS as a service.
In SNS you create subscriptions to a topic, one being a Lambda function. In my head I'd imagine this is to invoke and trigger the function when a message is sent out from that topic. But on the Lambda side you can create triggers to do that same thing, one of them being SNS.
What exactly is the difference, it kinda seems like they do the same thing. But if I create a subscription for a topic using a Lambda, it does not show up in the the triggers of the function in the Lambda services, which makes me wonder what exactly is the difference between these two?
What exactly is the difference?
There is no difference from the functional point of view. What you are observing are just console imperfections.
To make sure, I manually verified using my SNS and my lambda function.
When you use Create subscription in the SNS console, and add a lambda function, it does show up as a trigger in lambda console.
Similarly, if you use lambda console and add SNS trigger, you will find the function in the Subscriptions section of SNS console.
However, AWS console is not perfect. For example, if you remove the lambda function from Subscriptions, it will not remove it from triggers on lambda console. Instead you will see the following error:
For some this may be a bug, for others a feature. I learned not to rely heavily on what AWS console shows. Just double check if the subscription works or not.
I need to add 'SNS' based trigger to my Lambda function, But create-event-source-mapping — AWS CLI Command Reference says only DynamoDB, Kinesis, SQS.
The aws lambda create-event-source-mapping command for SNS, S3 etc based triggers fails with --event-source-arn:
An error occurred (InvalidParameterValueException) when calling the CreateEventSourceMapping operation: Unrecognized event source, must be kinesis, dynamodb stream or sqs. Unsupported source arn
However these can be accomplished through AWS console.
Any thoughts?
To have a SNS triggers a Lambda, the Lambda need to subscribe the SNS's topic. You can refer to Tutorial: Using AWS Lambda with Amazon Simple Notification Service on getting Lambda triggered when a message published to SNS's topic.
*the cdk construct lib links provided are in python but you can use a language or your choice
In order to set a sns trigger on Lambda you have do following things,
1) create a SNS Topic
2) create a Lambda function
3) create a Lambda event source
4) integrate all
You can use AWS CDK to do all this
Creating a SNS Topic:
https://docs.aws.amazon.com/cdk/api/latest/python/aws_cdk.aws_sns/Topic.html
Creating a Lambda Function
https://docs.aws.amazon.com/cdk/api/latest/python/aws_cdk.aws_lambda/Function.html
Use functuon_obj.add_ecent_source(SNS_obj) to integrate all.
The IAM permissions to invoke your function on sns event will automatically get handled and you see then under Lambda permissions tab on console.
Do mark the answer right if it helps.
I have created lambda and SNS using cloudformation. Here first lambda is invoking a SNS which has a subscription of another lambda. Here SNS is supposed to invoke alias of lambda. In SNS topic lambda ARN is showing as subscriber but in lambda it is not added as trigger. There is not a single invocation log of the lambda invoked from SNS. So is this problem about some kind of permission or else ? need help...
Yes, this is a permissions issue. You need to add a permission to the lambda function to allow SNS to invoke it.
Use the AWS::Lambda::Permission resource to add permissions to allow SNS to invoke the lambda function.
I had a heck of a time with one. I had originally set my lambda function to look for an event source of "aws:s3". In order to get the event source from an s3 event, I used "event.Records[0].eventSource". When I tested event.Records[0].eventSource == "aws:sns" to check if my SNS trigger had fired, it wouldn't work. It wasn't until I found sample SNS event JSON that I noticed that SNS events have an event source node of "EventSource". It's capital case. I changed my test to
event.Records[0].EventSource == "aws:sns"
and it worked. So much for consistency in event message formats.
I am trying to use boto3 to programmatically subscribe my lambda function to a sns topic. When I execute my script, I see the integration in the AWS Lambda Console but publishing to the SNS topic does not invoke the function.
I then created the integration between the SNS topic and Lambda function directly in the AWS console itself. The AWS Console adds an Identifier field with the sns arn as the value. Now, publishing to the topic invokes the function.
In my script,I have added permissions(lambda_client.add_permission) using the values:,
{'Action': 'lambda:InvokeFunction',
'FunctionName':'my_lambda',
'Principal': 'sns.amazonaws.com',
'SourceArn': 'arn:aws:sns:us-east-1:redacted_acct_no:my-topic',
'StatementId': 'lambda-03a99f95-f490-4b9c-8bf8-20ee85fb2bff'}
I also do
sns_client.subscribe() and have successfully subscribed the lambda function to the topic
For testing purposes, I created two integrations, to two different topics and I called lambda_client.get_policy() and the policies are identical(of course, the StatementIds are different.
I have a similar setup for S3 which works.
I have a lambda function that I'd like to trigger via HTTP request.
When I click add trigger to a lambda function, I get an API Gateway API set up with:
method: ANY
Great. Now, when viewing this lambda function, I see a trigger has been configured.
However, I would like to restrict the trigger to only allow POST requests.
So I deleted the API Gateway method ANY, and created a new method POST, under the same resource, using an integration type of Lambda Function. I select my region, and sure enough, my existing lambda function is autocompleted.
However, when I view the triggers tab on the lambda function itself, it shows that there are no triggers.
What am I missing?
If you need flexible control of the API, I would suggest to use the API Gateway console to mange your API. Lambda triggers should only be used for simple use-cases - API methods configured through API Gateway will not show up in the Lambda triggers list.