在线修改haproxy配置文件

#!/usr/bin/env python
# -*- coding:utf8 -*-
import os
import json

def fetch(backend):
        fetch_list = []
        with open('ha') as obj:
                flag = False
                for line in obj:
                        # line 每一行，
                        if line.strip() == "backend %s" % backend:
                                flag = True
                                continue
                        # 判断，如果当前是 backend开头，不再放
                        if flag and line.strip().startswith('backend'):
                                break
                        if flag and line.strip():
                                fetch_list.append(line.strip())
        return fetch_list

#result = fetch("buy.oldboy.org")
#print result
def adds(dict_info):
    #s = '{"backend": "www.oldboy.org","record":{"server": "100.1.7.9","weight": 20,"maxconn": 30}}'
        backend_title = dict_info.get('backend')
        current_title = "backend %s" % backend_title
        current_record = "server %s %s weight %s maxconn %s" % (dict_info['record']['server'],dict_info['record']['server'],dict_info['record']['weight'],dict_info['record']['maxconn'])
        # 获取制定backend下的所有记录
        fetch_list = fetch(backend_title)
        #print fetch_list
        # backend是否存在
        if fetch_list:
            #pass # 存在backend，则只需再添加记录
            # 1,要插入的记录，存在
            # 2,要插入的记录，不存在
            if current_record in fetch_list:
                    pass
            else:
                    fetch_list.append(current_record)#如果不存在直接将current_record追加到fetch_list中
            # 此时fetch_list为处理完的新列表
            with open('ha') as read_obj, open('ha.new', 'w') as write_obj:
                    flag = False
                    has_write = False
                    for line in read_obj:#读取原配置文件
                        if line.strip() == current_title:#如果读取的行内容与current_title相等，则把current_title写入到文件中，然后就跳出本次循环，
                                write_obj.write(line)
                                flag = True
                                continue
                        if flag and line.strip().startswith('backend'):#如果flag为真并且读取的line.strip内容是以"backend开头"，则将flag置False
                                flag = False
                        if flag:
                        #如果flag为True新的列表fetch_list所有数据一行一行的写入到新配置文件，即当遍历原配置文件中current_title标签下的current_record记录，如果curent_record有三条，则循环三次，每循环一次就将fetch_list完整遍历一次的然后一条一条地写入到新配置文件，所以这里要用一个标识符has_write作为判断是否写入，如果已经写入了就不再继续往新配置文件中写入
                                if not has_write:
                                   for new_line  in fetch_list:
                                        temp = "%s %s \n" %(" "*8, new_line)
                                        write_obj.write(temp)
                                   has_write = True
                        else:
                            # 不满足以上的各种情况则直接将内容写入新配置文件
                                write_obj.write(line)
        else:
                #pass,如果不存在backend，则添加backend和current_record
                # current_title,current_record
                # 直接打开文件
                with open('ha') as read_obj, open('ha.new', 'w') as write_obj:
                        for line in read_obj:
                                write_obj.write(line)
                        write_obj.write('\n'+current_title+'\n')#将要插入的current_title和两条current_record记录再写到新配置文件末尾
                        temp = "%s %s \n" %(" "*8, current_record)#把current_record两条记录写到新配置文件中
                        write_obj.write(temp)


#s = '{"backend": "test.oldboy.org","record":{"server": "10.10.10.9","weight": 20,"maxconn": 3000}}'
#data_dict = json.loads(s)
#adds(data_dict)

def remove(dict_info):
    backend_title = dict_info.get('backend')
    current_title = "backend %s" % backend_title
    current_record = "server %s %s weight %s maxconn %s" % (dict_info['record']['server'],dict_info['record']['server'],dict_info['record']['weight'],dict_info['record']['maxconn'])
    # 获取制定backend下的所有记录
    fetch_list = fetch(backend_title)
    if fetch_list:
       pass
    else:
         if current_record not in fetch_list:
            pass
         else:
            fetch_list[fetch_list.index(current_record)]
            if len(fetch_list) > 0:
                fetch_list.insert(0, backend_title)
         with open('ha') as read_file, open('ha.new', 'w') as write_file:
            flag = False
            has_write = False
            for line in read_file:
                line_strip = line.strip()
                if line_strip == backend_title:
                    flag = True
                    continue
                if flag and line_strip.startswith('backend'):
                    flag = False
                if not flag:
                    write_file.write(line)
                else:
                    if not has_write:
                        for i in fetch_list:
                            if i.startswith('backend'):
                                write_file.write(i+'\n')
                            else:
                                write_file.write("%s%s\n" % (8*" ", i))
                    has_write = True
       
       
os.rename("ha", 'ha.bak')
os.rename("ha.new", 'ha')
       


if  __name__ == '__main__':
    
    print '1、获取；2、添加；3、删除'
    num = raw_input('请输入序号：')
    data = raw_input('请输入内容：')
    if num == '1':
        fetch(data)
    else:
        dict_data = json.loads(data)
        if num == '2':
            add(dict_data)
        elif num == '3':
            remove(dict_data)
        else:
            pass