When you create a Lambda permission you send the __statement id__ as mandatory parameter.

https://docs.aws.amazon.com/lambda/latest/dg/API_AddPermission.html#API_AddPermission_RequestSyntax

However this id is generated by a random value. 

https://github.com/localstack/localstack/blob/b3917bf248b77ced8ef80a3d5c0561960066db5d/localstack/services/awslambda/lambda_api.py#L927

Due to this problem, the tools like Terraform or Ansible fail when it has to be retrieved to check the existence of this element.

If you agree I could make a PR with the fix and its test.
""" List functions
        ---
        operationId: 'listFunctions'
        parameters:
            - name: 'request'
              in: body
    """
    funcs = do_list_functions()
    result = {}
    result['Functions'] = funcs
    return jsonify(result)
@app.route('%s/functions/<function>' % PATH_ROOT, methods=['DELETE'])
def delete_function(function):
    """ Delete an existing function
        ---
        operationId: 'deleteFunction'
        parameters:
            - name: 'request'
              in: body
    """
    arn = func_arn(function)
    
    LAMBDA_EXECUTOR.cleanup(arn)
    try:
        arn_to_lambda.pop(arn)
    except KeyError:
        return not_found_error(func_arn(function))
    event_publisher.fire_event(event_publisher.EVENT_LAMBDA_DELETE_FUNC,
        payload={'n': event_publisher.get_hash(function)})
    i = 0