# Type of request: This is a ...

[*] bug report
[ ] feature request

# Detailed description

Perhaps not a bug report per se, but this affected me at least. A new version of `lambci/docker-lambda` was pushed recently. [This commit](https://github.com/lambci/docker-lambda/commit/7ece2742a5b0e84eb09d6ed659f123474e619b27) removed hardcoded defaults for `AWS_ACCESS_KEY_ID` and `AWS_SECRET_ACCESS_KEY`.

I have a lambda that reads a value from secret in `secretsmanager`. If I don't set dummy values for `AWS_ACCESS_KEY_ID` and `AWS_SECRET_ACCESS_KEY` when creating the lambda invoking it will time out reading the secret.

## Expected behavior

A lambda function can read a secret from `secretsmanager`.

## Actual behavior

Lambda times out trying to read secret.

# Steps to reproduce

Create a lambda which tries to read a secret from `secretsmanager` without adding the environments variables mentioned above.

## Command used to start LocalStack

## Client code (AWS SDK code snippet, or sequence of "awslocal" commands)

This will work:
```bash
awslocal lambda create-function \
  --function-name foo \
  --runtime go1.x \
  --handler main \
  --role arn:aws:iam::123456790:role/ignore \
  --zip-file fileb://foo.zip \
  --environment "Variables={FOO=bar,AWS_ACCOUNT_ID=123456790,AWS_ACCESS_KEY_ID=0,AWS_SECRET_ACCESS_KEY=0}"
```

This will time out while reading:
```bash
awslocal lambda create-function \
  --function-name foo \
  --runtime go1.x \
  --handler main \
  --role arn:aws:iam::123456790:role/ignore \
  --zip-file fileb://foo.zip \
  --environment "Variables={FOO=bar}"
```
"""
        Starts a repeating timer that triggers start_idle_container_destroyer_interval every 60 seconds.
        Thus checking for idle containers and destroying them.
        :return: None
        """
        self.idle_container_destroyer()
        threading.Timer(60.0, self.start_idle_container_destroyer_interval).start()
    def get_container_name(self, func_arn):
        """
        Given a function ARN, returns a valid docker container name.
        :param func_arn: The ARN of the lambda function.
        :return: A docker compatible name for the arn.
        """
        return 'localstack_lambda_' + re.sub(r'[^a-zA-Z0-9_.-]', '_', func_arn)
class LambdaExecutorSeparateContainers(LambdaExecutorContainers):
    def __init__(self):