[ python ] 项目：haproxy配置文件增删改查

1. 开发要求

实现对 haproxy.cfg 增删改查操作

2. 程序介绍

# 作者：hkey

# 博客地址：https://www.cnblogs.com/hukey/p/9288279.html

# 功能实现：对 haproxy.cfg 增删改查

# 目录结构：
haproxy/
├── haproxy.cfg     # haproxy 主配置文件
└── ops.py            # 操作程序


# 使用说明：

    1. 查询
    2. 新增
    3. 修改
    4. 删除
    5. 退出

3. 程序逻辑图

4. 程序代码

global
    log         127.0.0.1 local2

    chroot      /var/lib/haproxy
    pidfile     /var/run/haproxy.pid
    maxconn     4000
    user        haproxy
    group       haproxy
    daemon

    # turn on stats unix socket
    stats socket /var/lib/haproxy/stats

defaults
    mode                    http
    log                     global
    option                  httplog
    option                  dontlognull
    #option http-server-close
    #option forwardfor       except 127.0.0.0/8
    option                  redispatch
    retries                 3
    timeout http-request    10s
    timeout queue           1m
    timeout connect         10s
    timeout client          1m
    timeout server          1m
    timeout http-keep-alive 10s
    timeout check           10s
    maxconn                 3000

backend www.super.com
    server 10.0.10.1 weight 20 maxconn 30
    server 10.0.10.2 weight 999 maxconn 20

backend www.super1.com
    server 10.0.10.1 weight 20 maxconn 30
    server 10.0.10.2 weight 999 maxconn 20
    server 10.0.10.3 weight 999 maxconn 20

backend www.super2.com
    server 10.0.10.2 weight 20 maxconn 21
    server 10.0.10.20 weight 30 maxconn 40
    server 10.0.10.3 weight 20 maxconn 21
backend www.super20.com
    server 10.0.0.10 10.0.10.10 weight 20 maxconn 21

# -*- coding: utf-8 -*-
# Author: hkey
import os

def file_handle(backend_data, src=None, type='fetch'):
    '''解耦函数'''
    if type == 'fetch':
        with open('haproxy.cfg', 'r') as read_f:
            ret = []
            Flag = False
            for read_line in read_f:
                if backend_data == read_line.strip():
                    Flag = True
                    continue
                if Flag == True and read_line.startswith('backend'):
                    break
                if Flag:
                    print('33[42;1m%s33[0m' % read_line, end='')
                    ret.append(read_line)
        return ret

    elif type == 'change':
        with open('haproxy.cfg', 'r') as read_f, open('haproxy.conf', 'w') as write_f:
            flag = False
            has_write = False
            for read_line in read_f:
                if read_line.strip() == backend_data:
                    flag = True
                    continue
                if flag and read_line.startswith('backend'):
                    flag = False
                if not flag:
                    write_f.write(read_line)
                else:
                    if not has_write:
                        for record in src:
                            write_f.write(record)
                        has_write = True
        os.rename('haproxy.cfg', 'haproxy.cfg_bak')
        os.rename('haproxy.conf', 'haproxy.cfg')
        os.remove('haproxy.cfg_bak')


def fetch(find_str):
    '''查询功能'''
    backend_str = 'backend %s' % find_str
    return file_handle(backend_str)

def add(backend):
    '''新增功能'''
    print('这是新增功能.')
    backend_list = fetch(backend)
    if not backend_list:
        return '33[41;1mbackend不存在。33[0m'
    new_server = input('输入新增server:')
    backend_data = 'backend %s' % backend
    backend_list.insert(0, '%s
%s
' % (backend_data, new_server))
    return file_handle(backend_data, src=backend_list, type='change')


def change(modify_data):
    '''修改功能'''
    print('这是修改功能.')
    modify_data = eval(modify_data)
    backend = modify_data[0]['backend']
    backend_data = 'backend %s' % backend
    backend_list = fetch(backend)
    old_server = '%sserver %s weight %s maxconn %s
' %(' ' *4, modify_data[0]['record']['server'],
                                           modify_data[0]['record']['weight'], modify_data[0]['record']['maxconn'])
    new_server = '%sserver %s weight %s maxconn %s
' %(' ' *4, modify_data[1]['record']['server'],
                                           modify_data[1]['record']['weight'], modify_data[1]['record']['maxconn'])

    if not backend_list and old_server not in backend_list:
        return '修改的记录不存在。'
    else:
        index = backend_list.index(old_server)
        backend_list[index] = new_server
        backend_list.insert(0, '%s
' % backend_data)
        return file_handle(backend_data, src=backend_list, type='change')

def delete(backend):
    '''删除功能'''
    print('这是删除功能.')
    backend_list = fetch(backend)
    if not backend_list:
        return '33[41;1mbackend 【%s】不存在。33[0m' % backend
    del_server = input('输入要删除的server:') + '
'
    if del_server not in backend_list:
        return '33[41;1m输入的server不存在。33[0m'
    else:
        backend_data = 'backend %s' % backend
        backend_list.insert(0, '%s
' %backend_data)
        backend_list.remove(del_server)
        return file_handle(backend_data, src=backend_list, type='change')


if __name__ == '__main__':
    msg = '''
    1. 查询
    2. 新增
    3. 修改
    4. 删除
    5. 退出
    '''

    msg_dict = {
        '1': fetch,
        '2': add,
        '3': change,
        '4': delete,
    }

    while True:
        print(msg)
        choice = input('>>>').strip()
        if not choice: continue
        if choice == '5': break
        find_str = input('请输入你的数据：').strip()
        res = msg_dict[choice](find_str)
        print(res)

5. 程序运行展示

（1）查询

（2）新增

    server 1.1.1.1 weight 1 maxconn 1（前面4个空格）

（3）修改

[{'backend': 'www.super2.com', 'record':{'server': '10.0.10.20', 'weight': 30, 'maxconn': 40}}, {'backend': 'www.super2.com', 'record':{'server': '10.0.10.200', 'weight': 100, 'maxconn': 100}}]

（4）删除

    server 1.1.1.1 weight 1 maxconn 1（开头4个空格）

（5）退出