How to get the response from an AWS Python Lambda

Question

I have written some python code that I am running in AWS Lambda. When I test the Lambda in the Lambda AWS dashboard and it runs without any errors I see the following in the "Execution Results" tab :

Response: null
Request ID: "421fd7da-20f7-4029-aa8b-f7281e7c90d9"

If I get any errors when I run the Lambda I see JSON formated output in the "Execution Results" tab.

Here is an example :

Response:
{
  "errorMessage": "An error occurred (DBClusterNotFoundFault) when calling the CreateDBClusterSnapshot operation: DBCluster not found: ernie-export-test-db-clusterr",
  "errorType": "DBClusterNotFoundFault",
  "stackTrace": [
    "  File \"/var/task/lambda_function.py\", line 90, in main\n    response = create_snapshot(rds, snaptype, datestamp, deleteAfterDate)\n",
    "  File \"/var/task/lambda_function.py\", line 33, in create_snapshot\n    'Value': deleteafterdate\n",
    "  File \"/var/runtime/botocore/client.py\", line 272, in _api_call\n    return self._make_api_call(operation_name, kwargs)\n",
    "  File \"/var/runtime/botocore/client.py\", line 576, in _make_api_call\n    raise error_class(parsed_response, operation_name)\n"
  ]
}

How can I return this "Response" back into my Python code so I can use it/read it? In particular I want to read the "errorMessage" so my python code in the Lambda can print it out or forward it to - lets say to use in in an SNS.

I have added a return with response but its contents do not match up with what is in the response I get in the "Execution Results" tab.

Here is my Python code -

from __future__ import print_function
from boto3 import client
import datetime
from datetime import datetime

# Database cluster identifier that the backup will be performed on
CLUSTER_ID = "export-test-db-cluster"

# Name of the company that the script is used on
COMPANY = "Test"

# AWS region in which the db instances exist
REGION = "us-east-1"


def create_snapshot(rds, snaptype, datestamp, deleteafterdate):
    snapname = COMPANY + "-" + snaptype + "-" + datestamp
    response = rds.create_db_cluster_snapshot(
        DBClusterSnapshotIdentifier=snapname,
        DBClusterIdentifier=CLUSTER_ID,
        Tags=[
            {
                'Key': 'Name',
                'Value': snapname
            },
            {
                'Key': 'expirationDate',
                'Value': deleteafterdate
            },
        ]
    )
    return response


def main(event, context):
    rds = client("rds", region_name=REGION)
    now = datetime.now()
    # Should we leave time in the name?
    datestamp = now.strftime("%m-%d-%Y-%H-%M-%S")
    snaptype = "TestBackup"
    deleteAfterDate = "Today-test"
    create_snapshot(rds, snaptype, datestamp, deleteAfterDate)

Any help is appreciated!!

Answer 1

Should be something like this.

from __future__ import print_function
from boto3 import client
import datetime
from datetime import datetime

# Database cluster identifier that the backup will be performed on
CLUSTER_ID = "export-test-db-cluster"

# Name of the company that the script is used on
COMPANY = "Test"

# AWS region in which the db instances exist
REGION = "us-east-1"


def create_snapshot(rds, snaptype, datestamp, deleteafterdate):
    snapname = COMPANY + "-" + snaptype + "-" + datestamp
    try:
        response = rds.create_db_cluster_snapshot(
            DBClusterSnapshotIdentifier=snapname,
            DBClusterIdentifier=CLUSTER_ID,
            Tags=[
                {
                    'Key': 'Name',
                    'Value': snapname
                },
                {
                    'Key': 'expirationDate',
                    'Value': deleteafterdate
                },
            ]
        )
    except Exception as e:
        response = e
        pass
    return response


def main(event, context):
    rds = client("rds", region_name=REGION)
    now = datetime.now()
    # Should we leave time in the name?
    datestamp = now.strftime("%m-%d-%Y-%H-%M-%S")
    snaptype = "TestBackup"
    deleteAfterDate = "Today-test"
    my_response = create_snapshot(rds, snaptype, datestamp, deleteAfterDate)