对haproxy文件进行增删改查

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)