The specified log group already exists error for second run

[alexlai86]

Hi Mr. GeorgeDavis,

Thanks for the guide you provide. It is very useful. However, I face some issue for the lambda coding.

On the first run of a job, it creates the log stream and everything is fine. However, on subsequent jobs (update event log on next minutes) I get the error that the "The specified log group already exists", even though this job was the one that created it. The error as follows:

[ERROR] ResourceAlreadyExistsException: An error occurred (ResourceAlreadyExistsException) when calling the CreateLogGroup operation: The specified log group already exists
Traceback (most recent call last):
File "/var/task/lambda_function.py", line 86, in lambda_handler
createLogGroup(logGroupName)
File "/var/task/lambda_function.py", line 12, in createLogGroup
createLogGroupResponse = cwlogs.create_log_group(
File "/var/runtime/botocore/client.py", line 386, in _api_call
return self._make_api_call(operation_name, kwargs)
File "/var/runtime/botocore/client.py", line 705, in _make_api_call
raise error_class(parsed_response, operation_name)

The lambda code I used is as ur doc:

import os
import boto3
import string
import random
import json
import time

cwlogs = boto3.client('logs')

def createLogGroup(logGroupName):
createLogGroupResponse = cwlogs.create_log_group(
logGroupName=logGroupName,
tags={
"Owner": "TrendMicro",
"Product": "CloudOneWorkloadSecurity",
"Name": logGroupName
}
)

print("createLogGroupResponse - " + str(createLogGroupResponse))

def ifLogGroupExists(logGroupName):
listLogGroupsResponse = cwlogs.describe_log_groups()
for logGroup in listLogGroupsResponse["logGroups"]:
if logGroupName in logGroup["logGroupName"]:
return True
return False

def createLogStream(logGroupName, logStreamName):
createLogStreamResponse = cwlogs.create_log_stream(
logGroupName=logGroupName,
logStreamName=logStreamName
)

print("createLogStreamResponse - " + str(createLogStreamResponse))

if createLogStreamResponse["ResponseMetadata"]["HTTPStatusCode"] == 200:
    return logStreamName
return ""

def putLogEvents(logGroupName, logStreamName, logEvent, nextSequenceToken=None):

if nextSequenceToken:
    putLogEventsResponse = cwlogs.put_log_events(
        logGroupName=logGroupName,
        logStreamName=logStreamName,
        logEvents=logEvent,
        sequenceToken=nextSequenceToken
    )
else:
    putLogEventsResponse = cwlogs.put_log_events(
        logGroupName=logGroupName,
        logStreamName=logStreamName,
        logEvents=logEvent
    )

print("putLogEventsResponse - " + str(putLogEventsResponse))

if "rejectedLogEventsInfo" not in putLogEventsResponse:
    return putLogEventsResponse["nextSequenceToken"]
return None

def lambda_handler(event, context):

nextSequenceToken = None

logGroupName = str(os.environ.get("CloudWatchLogGroupName"))
logStreamNamePrefix = str(os.environ.get("CloudWatchLogStreamNamePrefix"))

nonce = ''.join(random.choices(
    string.ascii_letters + string.digits, k=8)).upper()

logEvents = json.loads(event["Records"][0]["Sns"]["Message"])

if len(logEvents) > 0:

    if ifLogGroupExists(logGroupName):
        logStreamName = createLogStream(
            logGroupName, logStreamNamePrefix + "-" + nonce)
    else:
        createLogGroup(logGroupName)
        logStreamName = createLogStream(
            logGroupName, logStreamNamePrefix + "-" + nonce)

    print(str(logGroupName) + " - " + str(logStreamName))

    for message in logEvents:

        epoch_time = int(round(time.time() * 1000))

        logEvent = []
        logEvent.append({"timestamp": epoch_time, "message": str(message)})

        nextSequenceToken = putLogEvents(
            logGroupName, logStreamName, logEvent, nextSequenceToken)

        if nextSequenceToken == None:
            return False

Regards,
Alex Lai (alex.lai@ecloudvalley.com)