python - 使用 boto 的 AWS DB 安全组(捕获异常)

Question

我正在使用 boto 创建数据库安全组。我想要这样的东西:

• 如果数据库安全组存在，检查给定规则，如果不存在，则使用规则授权组
• 如果该组不存在，则创建它，并使用给定的规则授权该组

到目前为止，这是我的代码:

import boto.rds
conn = boto.rds.connect_to_region("{{region}}", aws_access_key_id = '{{ keyid }}', aws_secret_access_key = '{{ key }}')

group = conn.get_all_dbsecurity_groups('{{name}}')

if group:
    group[0].authorize({{ connection_type }} = '{{ details }}')
else: 
    sg = conn.create_dbsecurity_group('{{ name }}', '{{ description }}')
    sg.authorize({{ connection_type }} = '{{ details }}')

我遇到了这个错误:

未找到 DBSecurityGroup

 Traceback (most recent call last):
    File "/usr/local/src/dbgroups.py", line 18, in <module>
        group = conn.get_all_dbsecurity_groups('kdkdkdk')
    File "/usr/local/lib/python2.7/site-packages/boto/rds/__init__.py", line 923, in get_all_dbsecurity_groups
        [('DBSecurityGroup', DBSecurityGroup)])
    File "/usr/local/lib/python2.7/site-packages/boto/connection.py", line 1186, in get_list
        raise self.ResponseError(response.status, response.reason, body)
    boto.exception.BotoServerError: BotoServerError: 404 Not Found
    <ErrorResponse xmlns="http://rds.amazonaws.com/doc/2013-05-15/">
        <Error>
            <Type>Sender</Type>
            <Code>DBSecurityGroupNotFound</Code>
            <Message>DBSecurityGroup dbgrouptesting not found.</Message>
        </Error>
        <RequestId>3b9af082-fe3c-11e4-bd53-e9bc444dcde5</RequestId>
    </ErrorResponse>

授权已经存在

Traceback (most recent call last):
    File "/usr/local/src/dbgroups.py", line 24, in <module>
        group[0].authorize(cidr_ip = '0.0.0.0/0')
    File "/usr/local/lib/python2.7/site-packages/boto/rds/dbsecuritygroup.py", line 109, in authorize
        group_owner_id)
    File "/usr/local/lib/python2.7/site-packages/boto/rds/__init__.py", line 995, in authorize_dbsecurity_group
        DBSecurityGroup)
    File "/usr/local/lib/python2.7/site-packages/boto/connection.py", line 1208, in get_object
        raise self.ResponseError(response.status, response.reason, body)
    boto.exception.BotoServerError: BotoServerError: 400 Bad Request
    <ErrorResponse xmlns="http://rds.amazonaws.com/doc/2013-05-15/">
        <Error>
            <Type>Sender</Type>
            <Code>AuthorizationAlreadyExists</Code>
            <Message>Authorization already exists: 0.0.0.0/0</Message>
        </Error>
    <RequestId>5fc68ac7-fe3b-11e4-b082-0b206bb7b937</RequestId>
    </ErrorResponse>

Answer 1

当请求的安全组不存在时，boto 函数看起来不像是返回 nil 或空响应，而是抛出 DBSecurityGroupNotFound 异常。因此，请更改您的代码以使用 try/except 而不是“if group”。

像这样:

try:
  group = conn.get_all_dbsecurity_groups('{{name}}')
  group[0].authorize({{connection_type}} = '{{details}}')
except boto.exception.BotoServerError as e:
  if (e.status == 400 && e.error_code == 'DBSecurityGroupNotFound'):
    sg = conn.create_dbsecurity_group('{{name}}', '{{description}}')
    sg.authorize({{connection_type}} = '{{details}}')
  else:
    raise;

您还需要处理来自“授权”调用的潜在错误。

或者，预先获取所有安全组的列表，然后在该列表中找到所需的安全组并相应地进行。