Question

我想列出AWS云组合中与正则表达式匹配的所有活动堆栈。堆栈的名称就像这个'FeatureEnv-commit123asdfqw212da-3241'。实现这一目标的最佳方法是什么？每当我运行脚本时，它都会抛出错误。完整的脚本http://www.technobabelfish.com/2013/08/boto-and-cloudformation.html。我已经更新了该脚本以满足我的要求。

#!/usr/bin/env python

import sys
import boto
import boto.cloudformation
import argparse
import re

class MyBaseException(Exception):
    msg ="MyBaseException"
    def __init__(self, value):
        self.value = value
    def __str__(self):
        return "%s: %s" % (self.msg, self.value)

class MissingParamException(MyBaseException):
    msg ="Missing param"

class InvalidCommandException(MyBaseException):
    msg ="Invalid command"

class InvalidStackException(MyBaseException):
    msg ="Invalid stack"


def _create_cf_connection(args):
    # Connect to a cloudformation
    # Returns a cloudformation connection.
    # Throws exception if connect fails
    if not args.access_key:
        raise MissingParamException("access_key")

    if not args.secret_key:
        raise MissingParamException("secret_key")

    if not args.region:
        raise MissingParamException("region")

    conn = boto.cloudformation.connect_to_region(args.region,
                                                 aws_access_key_id = args.access_key,
                                                 aws_secret_access_key = args.secret_key)

    return conn

def get_stacks(args):
    conn = _create_cf_connection(args)
    return conn.list_stacks()

def get_stack(args, stack):
    conn = _create_cf_connection(args)

    stacks = conn.describe_stacks(stack)
    if not stacks:
        raise InvalidStackException(stack)

    return stacks[0]

def print_stack(stack):
    print "---"
    print "Name:            %s" % stack.stack_name
    print"ID:              %s"% stack.stack_id
    print "Status:          %s" % stack.stack_status
    print "Creation Time:   %s" % stack.creation_time
    print"Outputs:         %s"% stack.outputs
    print "Parameters:      %s" % stack.parameters
    print"Tags:            %s"% stack.tags
    print "Capabilities:    %s" % stack.capabilities


def list_stacks(args):
    stacks = get_stacks(args)
    for stackSumm in stacks:
         pattern = re.compile("^FeatureEnv-commit([a-z][0-9]+)*-([0-9]*)")
         match = pattern.match(stackSumm.stack_name)
         print match.string
         if stackSumm.stack_status in "CREATE_COMPLETE" and match and stackSumm.stack_name in match.string:
             print_stack(get_stack(args, stackSumm.stack_id))


def list_regions(args):
    regions = boto.cloudformation.regions()

    for r in regions:
        print r.name


command_list = { 'list-regions' :   list_regions,
                 'list-stacks'  :   list_stacks,
               }


def parseArgs():
    parser = argparse.ArgumentParser()
    parser.add_argument("--region" )
    parser.add_argument("--command" )
    parser.add_argument("--access-key" )
    parser.add_argument("--secret-key" )
    args = parser.parse_args()

    if not args.command:
        raise MissingParamException("command")

    if args.command not in command_list:
        raise InvalidCommandException(args.command)

    command_list[args.command](args)
if __name__=='__main__':
    try:
        parseArgs()
    except Exception, e:
        print e

错误：

  'NoneType' object has no attribute 'string'

Answer 1

错误在此声明stackSumm.stack_name in pattern中。在这种情况下，pattern是_sre.SRE_Pattern对象，而不是字符串。包含匹配结果的字符串是：

match = pattern.match(stackSumm.stack_name)
print match.string

字符串是可迭代的。因此，您可以安全地检查重新表达式的匹配中是否包含堆栈名称：

if stackSumm.stack_status in "CREATE_COMPLETE" and match and stackSumm.stack_name in match.string:
    print_stack(get_stack(args, stackSumm.stack_id))

模式与if语句匹配

1 个答案: