AWS Lambda Function scenarios to Access Secrets Manager with 'Access Denied' scenarios despite Policy Being Correct
Could someone explain I'm learning this framework and I've been banging my head against this for hours... I've been banging my head against this for hours. I'm currently working on an AWS Lambda function in Python (using the AWS SDK Boto3 version 1.18) that needs to access secrets stored in AWS Secrets Manager. However, I'm running into an `AccessDeniedException` behavior when the function tries to retrieve the secret. The behavior message states: `An behavior occurred (AccessDeniedException) when calling the GetSecretValue operation: User: arn:aws:sts::123456789012:assumed-role/MyLambdaRole/... is not authorized to perform: secretsmanager:GetSecretValue on resource: arn:aws:secretsmanager:us-east-1:123456789012:secret:MySecret`. I've double-checked the IAM role associated with the Lambda function and it seems to have the correct permissions. Here’s the IAM policy I attached to the role: ```json { "Version": "2012-10-17", "Statement": [ { "Effect": "Allow", "Action": [ "secretsmanager:GetSecretValue" ], "Resource": "arn:aws:secretsmanager:us-east-1:123456789012:secret:MySecret" } ] } ``` I also made sure that the secret exists in the specified region and that the resource ARN is correctly formatted. To confirm that the role is indeed attached to my Lambda function, I checked the Configuration settings in the AWS Lambda console. The Lambda function is triggered by an API Gateway request, and I’m testing it using Postman. In addition to checking the IAM policy, I’ve also tried adding resource-based policies directly to the secret itself to allow access by the Lambda function's execution role. However, I still encounter the same behavior. I would really appreciate any insights on why this might be happening or if there are specific logs I should review to troubleshoot further. What's the best practice here? Thanks in advance! Any advice would be much appreciated. The stack includes Python and several other technologies. I'm developing on Windows 10 with Python. Any ideas how to fix this?