Sometimes, attempting to run lambdas will return this type of error:
```
{"Type": "Server", "message": "Error executing Lambda function arn:aws:lambda:ap-northeast-1:000000000000:function:service-stage-functionName: An error occurred (ResourceAlreadyExistsException) when calling the CreateLogGroup operation: The specified log group already exists Traceback (most recent call last):\n 
File \"/opt/code/localstack/localstack/services/awslambda/lambda_api.py\", line 338, in run_lambda\n 
event, context=context, version=version, asynchronous=asynchronous)\n 
File \"/opt/code/localstack/localstack/services/awslambda/lambda_executors.py\", line 81, in execute\n 
return do_execute()\n File \"/opt/code/localstack/localstack/services/awslambda/lambda_executors.py\", line 70, in do_execute\n self._store_logs(func_details, log_output, invocation_time)\n 
File \"/opt/code/localstack/localstack/services/awslambda/lambda_executors.py\", line 105, in _store_logs\n logs_client.create_log_group(logGroupName=log_group_name)\n 
File \"/opt/code/localstack/.venv/lib/python3.6/site-packages/botocore/client.py\", line 357, in _api_call\n 
return self._make_api_call(operation_name, kwargs)\n 
File \"/opt/code/localstack/.venv/lib/python3.6/site-packages/botocore/client.py\", line 661, in _make_api_call\n 
raise error_class(parsed_response, operation_name)\n
botocore.errorfactory.ResourceAlreadyExistsException: An error occurred (ResourceAlreadyExistsException) when calling the CreateLogGroup operation: The specified log group already exists\n", "__type": "InternalFailure"}
```
I am not yet sure if there are any particular settings that cause it, since it does not occur for certain deployments.

Will update if I can figure out the exact configuration.
from localstack import config
from localstack.utils.aws import aws_stack
from localstack.utils.common import (
    CaptureOutput, FuncThread, TMP_FILES, short_uid, save_file,
    to_str, run, cp_r, json_safe, get_free_tcp_port)
from localstack.services.install import INSTALL_PATH_LOCALSTACK_FAT_JAR
LAMBDA_EXECUTOR_JAR = INSTALL_PATH_LOCALSTACK_FAT_JAR
LAMBDA_EXECUTOR_CLASS = 'cloud.localstack.LambdaExecutor'
EVENT_FILE_PATTERN = '%s/lambda.event.*.json' % config.TMP_FOLDER
LAMBDA_RUNTIME_PYTHON27 = 'python2.7'
LAMBDA_RUNTIME_PYTHON36 = 'python3.6'
LAMBDA_RUNTIME_NODEJS = 'nodejs'
LAMBDA_RUNTIME_NODEJS610 = 'nodejs6.10'
LAMBDA_RUNTIME_NODEJS810 = 'nodejs8.10'
LAMBDA_RUNTIME_NODEJS10X = 'nodejs10.x'
LAMBDA_RUNTIME_JAVA8 = 'java8'
LAMBDA_RUNTIME_DOTNETCORE2 = 'dotnetcore2.0'
LAMBDA_RUNTIME_DOTNETCORE21 = 'dotnetcore2.1'
LAMBDA_RUNTIME_GOLANG = 'go1.x'
LAMBDA_RUNTIME_RUBY = 'ruby'
LAMBDA_RUNTIME_RUBY25 = 'ruby2.5'
LAMBDA_RUNTIME_CUSTOM_RUNTIME = 'provided'
LAMBDA_EVENT_FILE = 'event_file.json'
LAMBDA_SERVER_UNIQUE_PORTS = 500
LAMBDA_SERVER_PORT_OFFSET = 5000
LOG = logging.getLogger(__name__)
MAX_CONTAINER_IDLE_TIME_MS = 600 * 1000
class LambdaExecutor(object):
    """ Base class for Lambda executors. Subclasses must overwrite the _execute method """
    def __init__(self):