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

        server 100.1.7.19 100.1.7.19 weight 40 maxconn 4000

backend buy.oldboy.org

        server 100.1.7.90 100.1.7.90 weight 20 maxconn 3000

filename = 'text_file\haproxy'

def fetch(backend):

    '''获取文件数据'''

    with open(filename, 'r') as f:

        result = []

        flag = False

        for line in f:

            if line.strip().startswith('backend') and line.strip() == 'backend ' + backend:

                flag = True

                continue

            elif flag and line.startswith('backend'):

                break

            elif flag and line.strip():

                result.append(line.strip())

    return result

#测试

ret = fetch("www.oldboy.org")

print(ret)

def add(backend,record):

    '''增加文件数据'''

    record_list = fetch(backend)

    #先检查backend是否存在

    if not record_list:

        #backend不存在

        with open(filename,'r') as old,open(r'text_file\new','w') as new:

            for line in old:

                new.write(line)

            new.write("\n\nbackend " + backend)

            new.write("\n" + " "*8 + record)

    else:

        #backend存在,判断记录是否存在

        if record in record_list:

            #record存在

            print("记录已存在")

        else:

            #backend存在，record不存在

            record_list.append(record)

            with open(filename,'r') as old,open(r'text_file\new2','w') as new2:

                flag = False

                for line in old:

                    if line.strip().startswith('backend') and line.strip() == 'backend ' + backend:

                        #找到backend www.oldboy.org

                        flag = True

                        new2.write(line)#把backend行加入新文件

                        for new_record in record_list:

                            #把record列表中的元素添加到新文件

                            new2.write(" " * 8 + new_record + "\n")

                        continue

                    if flag and line.startswith('backend'):

                        flag = False

                        new2.write("\n" + line)

                        continue

                    if flag == False:

                        new2.write(line)

#测试

bk = "www.oldboy.org"

rd = "server 34.1.7.25 100.1.7.44 weight 99 maxconn 67"

add(bk,rd)

bk = "test.oldboy.org"

rd = "server 50.1.7.55 100.1.7.45 weight 99 maxconn 89"

add(bk,rd)

def delete(backend,record):

    '''删除文件数据'''

    #先判断backend是否存在

    record_list = fetch(backend)

    if not record_list:

        print("记录不存在")

    else:

        with open(filename,'r') as f,open(r'text_file\new3','w') as new3:

            if record in record_list:

                for line in f:

                    if line.strip() == record:

                        continue

                    else:

                        new3.write(line)

#测试

bk = "www.oldboy.org"

rd = "server 100.1.7.9 100.1.7.9 weight 20 maxconn 3000"

delete(bk,rd)