修改haproxy配置文件  只需要寫刪除 增加 查詢，修改暫時不寫

需求：
1、查
    輸入：www.oldboy.org
    獲取當前backend下的所有記錄

2、新建
    輸入：
        arg = {
            ‘bakend‘: ‘www.oldboy.org‘,
            ‘record‘:{
                ‘server‘: ‘100.1.7.9‘,
                ‘weight‘: 20,
                ‘maxconn‘: 30
            }
        }

 
3、刪除
    輸入：
        arg = {
            ‘bakend‘: ‘www.oldboy.org‘,
            ‘record‘:{
                ‘server‘: ‘100.1.7.9‘,
                ‘weight‘: 20,
                ‘maxconn‘: 30
            }
        }

原配置文件
global       
        log 127.0.0.1 local2
        daemon
        maxconn 256
        log 
 
127.0.0.1 local2 info
defaults
        log global
        mode http
        timeout connect 5000ms
        timeout client 50000ms
        timeout server 50000ms
        option  dontlognull

listen stats :8888
        stats enable
        stats uri       /admin
        stats auth      admin:1234

frontend oldboy.org
        bind 
 
0.0.0.0:80
        option httplog
        option httpclose
        option  forwardfor
        log global
        acl www hdr_reg(host) -i www.oldboy.org
        use_backend www.oldboy.org if www

backend www.oldboy.org
        server 100.1.7.9 100.1.7.9 weight 20 maxconn 3000

#代碼部分：
print("1. Search \n2. Add \n3. Delete")
choose = input("Please choose:")
if choose == "1":
   search = input("search:")
   search = "backend " + search   # 只需要輸入網址，後面做完全匹配
   with open("haproxy","r",encoding="utf-8") as f:
       for line in f:   # 叠代器中循環
           if search == line.strip():
               print(line.strip())
               print(f.readline().strip())   # 讀取符合搜索條件的下一行,即配置信息，完成搜索功能

elif choose == "2":
   add_server = eval(input("Please add new server config:"))   # 這裏在輸入配置的時候，不能換行，所以弄成一行. eval()函數將字符串轉換成字典數據類型。{‘backend‘:‘www.oldboy.org‘,‘record‘:{‘server‘:‘100.1.7.9‘,‘weight‘:20,‘maxconn‘:30}}
   #print(add_server)
   with open("haproxy","a",encoding="utf-8") as f:
       f.write("backend {backend}\n".format(backend = add_server[‘backend‘]))
       f.write("       server {server} {server} weight {weight} maxconn {maxconn}\n".format(server = add_server[‘record‘][‘server‘],weight = add_server[‘record‘][‘weight‘],maxconn = add_server[‘record‘][‘maxconn‘]))
   print("Add, ok.")

elif choose == "3":
   #print("delete")
   delete_server = eval(input("Please delete server config:"))   # 輸入：{‘backend‘:‘www.oldboy.org‘,‘record‘:{‘server‘:‘100.1.7.9‘,‘weight‘:20,‘maxconn‘:30}}
   backend_delete = delete_server[‘backend‘]    # 逐個取出需要匹配的元素
   server_delete = delete_server[‘record‘][‘server‘]
   weight_delete = delete_server[‘record‘][‘weight‘]
   maxconn_delete = delete_server[‘record‘][‘maxconn‘]
   with open("haproxy","r",encoding="utf-8") as f:
       haproxy_lines = f.readlines()                # 將配置文件直接全部讀入到列表，因為配置文件比較小，就這樣幹了
   backend_delete_backend = "backend "+backend_delete  # 拼接後是這樣的：backend www.oldboy.org
   delete_index = list()  # 定義一個空列表，用來裝即將要刪除的元素下標
   for index,line in enumerate(haproxy_lines):
       if backend_delete_backend == line.strip():    # 先用backend www.oldboy.org來查找，後面再進行配置文件的完全匹配
           delete_record = haproxy_lines[index+1].strip().split(" ")    #  server 100.1.7.9 100.1.7.9 weight 20 maxconn 3000  轉化成了列表
           #print(delete_record)  [‘server‘, ‘100.1.7.9‘, ‘100.1.7.9‘, ‘weight‘, ‘20‘, ‘maxconn‘, ‘3000‘]
           if delete_record[1] == server_delete and int(delete_record[4]) == weight_delete and int(delete_record[6]) == maxconn_delete:   # 進行配置文件的完全匹配，符合條件的行索引加入delete_index列表
               #print(index,line)
               delete_index.append(index)
               delete_index.append(index+1)
   #print(delete_index)    # 得到待刪除行索引的列表[29, 30, 39, 40, 41, 42]
   count = 0
   with open(‘haproxy‘,‘w‘,encoding=‘utf-8‘) as f:   # 重寫配置文件，需要刪除的不寫入文件
       for line in haproxy_lines:
           if count not in delete_index:
               #print(count, line)
               f.write(line)
           count += 1
   print("Delete, OK.")
else:
   print("Wrong choice.")
   exit()

第三周作業：修改haproxy配置文件