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.
parameters:
    """
    arn = func_arn(function)
    lambda_cwd = arn_to_lambda[arn].cwd
    tmp_file = '%s/%s' % (lambda_cwd, LAMBDA_ZIP_FILE_NAME)
    return Response(load_file(tmp_file, mode='rb'),
            mimetype='application/zip',
            headers={'Content-Disposition': 'attachment; filename=lambda_archive.zip'})
@app.route('%s/functions/<function>/configuration' % PATH_ROOT, methods=['GET'])
def get_function_configuration(function):
    """ Get the configuration of an existing function
        ---
        operationId: 'getFunctionConfiguration'
        parameters:
    """
    arn = func_arn(function)
    lambda_details = arn_to_lambda.get(arn)
    if not lambda_details:
        return not_found_error(arn)
    result = format_func_details(lambda_details)
    return jsonify(result)
@app.route('%s/functions/<function>/configuration' % PATH_ROOT, methods=['PUT'])
def update_function_configuration(function):
    """ Update the configuration of an existing function
        ---
        operationId: 'updateFunctionConfiguration'
        parameters:
            - name: 'request'
              in: body
    """