#！C:\Program Files\Python35\bin

# -*- conding:utf-8 -*-

# author: Frank

def search_backend():

    search_list=[] #定义一个空列表，存放所查到backend的信息

    search_input = input("please input the backend which you want to search\n")

    with open ('Haproxy.cfg') as f:

        backend_flag = False #初始化标志位False

        for line in f:

            if line.strip()== 'backend %s'%search_input: #当匹配到所要查询的backend信息时，标志位为True，跳出本次循环，继续下一次循环

                backend_flag = True

                continue

            if backend_flag and line.strip().startswith('backend'): #上一个if语句，将标志位置为True，当再次遇到以’backend‘ 开头时

                                                                    #已经为下一个backend信息

                break

            if backend_flag and line.strip():  # 将上两个if条件除外的行追加到列表 search_list，即我们想要的行

                search_list.append(line.strip())

    if len(search_list) == 0:

        print("\033[31;1m%s not exit, please re_input\033[0m"%search_input)

        search_backend()

    else:

        for node in search_list:  #打印列表的每一行

            print(node)

def add_backend():

    args = '''{

                'backend':'%s',

                'record':{

                    'server':'%s',

                    'weight':'%s',

                    'maxconn':'%s'

                }

    }'''%(input('backend:'),input('server:'),input('weight:'),input('maxconn:'))

    b = eval(args)

    with open('Haproxy.cfg','a+',encoding='utf-8') as f:

        #print(' ',file=f)

        print('backend %s'%b['backend'],file=f,flush=True) #通过两个print， 将backend， 和下面的一行从格式上区别开

        print('\t\tserver %s weight %s maxconn %s'%(b['record']['server'],b['record']['weight'],b['record']['maxconn']),file=f,flush=True)

def delete_backend():

    # 删除正好和查询的思路相反，search 是将结果追加到列表里， delete是将所要删除的排除在外

    with open('Haproxy.cfg','r') as f_ori, open('Haproxy_new.cfg','a+') as f_new:

        delete_input=input("please enter backend which you want to delete:")

        backend_flag=True

        for line in f_ori:

            if line.strip() == 'backend %s'%delete_input:

                backend_flag=False

                continue

            if line.strip().startswith('backend') and line.strip() != 'backend %s' %delete_input:

                backend_flag=True

            if backend_flag: #除删除之外的所有行写到一个新的文件里

                f_new.write(line)

Mesg = '''1. Search backend

2. Add backend

3. delete backend

4. quit

'''

while True:

    print(Mesg)

    user_input = input("please input which do you want:")

    if user_input == "":

        search_backend()

    elif user_input == "":

        add_backend()

    elif user_input == "":

        delete_backend()

    elif user_input == '':

        exit()

    else:

        exit(print("Invaild input ,exit"))

#执行结果

1. Search backend

2. Add backend

3. delete backend

4. quit

please input which do you want:1

please input the backend which you want to search

www.baidu.com

server 10.22.23.45 weight 20 maxconn 30000

1. Search backend

2. Add backend

3. delete backend

4. quit

please input which do you want:2

backend:www.google.cn

server:10.88.123.40

weight:20

maxconn:3400

1. Search backend

2. Add backend

3. delete backend

4. quit

please input which do you want:4

>>> a = '''{

...         'backend':'www.baidu.com',

...          'record':{

...                     'weight':'20',

...                      'maxconn':'3400'

...                    }

...         }'''

>>> a

"{\n\t    'backend':'www.baidu.com',\n\t     'record':{\n\t\t\t'weight':'20',\n\t\t\t 'maxconn':'3400'\n\t\t       }\n        }"

>>> eval(a)

{'record': {'weight': '', 'maxconn': ''}, 'backend': 'www.baidu.com'}

>>>