使用 if 条件中断 while 循环

Question

我正在做一个自动化 AMI 创建的项目。 要求： 1. 创建 AMI 2. 等到 AMI 创建 3. 如果 AMI 创建失败或成功，则中断循环 4. 对所有实例重复该过程

我们不想在创建 AMI 时重启实例。

问题：当我将 break 语句添加到 if 条件时，脚本不会终止内部 while 循环。 有人可以帮我修复代码吗？

#!/usr/bin/env python
import sys
import boto
import boto.ec2
import datetime
import time

list_1 = ['instance1','instance2']
conn = boto.ec2.connect_to_region('us-west-1',aws_access_key_id = '<access_key>',aws_secret_access_key = '<secret_key>')

def create_img(a, b):
    try:
        print "Starting AMI creation for : %s" % inst.tags['Name']
        img_id = conn.create_image(a, b, description='backup', no_reboot=True, dry_run=False)
    except boto.exception.BotoServerError, e:
        print e.error_message
    return(img_id)


reservations = conn.get_all_instances()
for res in reservations:
    for inst in res.instances:
        if 'Name' in inst.tags and inst.tags['Name'] in list_1:
            print "%s (%s) [%s]" % (inst.tags['Name'], inst.id, inst.state)

            name = inst.tags['Name'] + '-' + datetime.datetime.now().strftime("%Y%m%d%H%M")
            ami_id = create_img(inst.id, name)
            img = conn.get_all_images(filters={'image_id' : ami_id})[0]

            if img.state == 'failed':
                print "AMI creation failed for instance: %s" % inst.tags['Name']
            elif img.state == 'pending':
                while True:
                    if img.state == 'failed':
                        print "AMI creation failed for instance: %s" % inst.tags['Name']
                        break
                    elif img.state == 'available':
                        print "AMI creation completed for instance: %s" % inst.tags['Name']
                        break
                    else:
                        time.sleep(60)
            elif img.state == 'available':
                print "AMI creation completed for instance: %s" % inst.tags['Name']
            else:
                print "Couldn't find the AMI"

Answer 1

您需要通过调用img.update()来更新状态。 状态信息不会自动更新。 对 AWS 的调用仅用于响应 boto API 调用。

        img = conn.get_all_images(filters={'image_id' : ami_id})[0]

        if img.state == 'failed':
            print "AMI creation failed for instance: %s" % inst.tags['Name']
        elif img.state == 'pending':
            while True:
                if img.state == 'failed':
                    print "AMI creation failed for instance: %s" % inst.tags['Name']
                    break
                elif img.state == 'available':
                    print "AMI creation completed for instance: %s" % inst.tags['Name']
                    break
                else:
                    time.sleep(60)
                    img.update()