解析 keepalived.conf，转换为 JSON

Question

有没有什么好的方法（最好是用Python）来解析keepalived.conf这个格式，并把它转换成json格式？我想自动化添加和删除虚拟服务器和真实服务器。

我第一反应是用pyparsing，参考了一些StackOverflow上的回答，但我就是搞不定！

keepalived.conf的格式是这样的：

virtual_server 192.168.1.1 80
{
lb_algo wrr
lb_kind DR
protocol TCP
ha_suspend
delay_loop 10

    # server-01
real_server 192.168.1.100 80
{
    weight 100
    inhibit_on_failure
    TCP_CHECK
    {
        connect_port 80
        connect_timeout 5
    }
}
# server-02
real_server 192.168.1.101 80
{
    weight 100
    inhibit_on_failure
    TCP_CHECK
    {
        connect_port 80
        connect_timeout 5
    }
  }
}

提前谢谢你们！

Answer 1

这是对解析这些数据的一个初步尝试：

from pyparsing import *

# basic punctuation - useful in parsing, but suppress from results    
LBRACE,RBRACE = map(Suppress, "{}")

# some simple terminals
ipv4_address = Regex(r"\d{1,3}(\.\d{1,3}){3}")
ipv6_address = Regex(r"[0-9a-fA-F:]+")
ip_address = ipv4_address | ipv6_address
integer = Word(nums).setParseAction(lambda t:int(t[0]))

# config parameters that take 0 or 1 arguments    
config_param0 = oneOf("ha_suspend inhibit_on_failure")
config_param1 = oneOf("""lb_algo b_kind protocol delay_loop weight 
                         connect_port connect_timeout""")
param_arg = integer | Word(alphanums)
config_param = Group(config_param1 + param_arg) | config_param0

# definitions for a real_server    
tcp_check = ("TCP_CHECK" + LBRACE + 
                OneOrMore(config_param) +
                RBRACE)

real_defn = Group("real_server" + 
                ip_address("rip_address") + 
                integer("rport") + LBRACE +
                ZeroOrMore(config_param)("params") + 
                tcp_check("tcp_check") + RBRACE
                )

# definiton for a virtual_server                    
virtual_defn = ("virtual_server" + 
                ip_address("vip_address") + 
                integer("vport") + LBRACE +
                ZeroOrMore(config_param)("params") + 
                OneOrMore(real_defn)("real_defns") + RBRACE
                )

# skip over comments
comment = '#' + restOfLine
virtual_defn.ignore(comment)

# parse the input string and dump out the pieces
confdata = virtual_defn.parseString(conf)
print confdata.dump()
for rip in confdata.real_defns:
    print
    print rip.dump()

输出结果如下：

['virtual_server', '192.168.1.1', 80, ['lb_algo', 'wrrl'], ...
- params: [['lb_algo', 'wrrl'], ['b_kind', 'DR'], ['protocol', 'TCP'], 
            'ha_suspend', ['delay_loop', 10]]
- real_defns: [['real_server', '192.168.1.100', 80, ['weight', ...
- vip_address: 192.168.1.1
- vport: 80

['real_server', '192.168.1.100', 80, ['weight', 100], 'inhibit_on_fa...
- params: [['weight', 100], 'inhibit_on_failure']
- rip_address: 192.168.1.100
- rport: 80
- tcp_check: ['TCP_CHECK', ['connect_port', 80], ['connect_timeout', 5]]

['real_server', '192.168.1.101', 80, ['weight', 100], 'inhibit_on_fai...
- params: [['weight', 100], 'inhibit_on_failure']
- rip_address: 192.168.1.101
- rport: 80
- tcp_check: ['TCP_CHECK', ['connect_port', 80], ['connect_timeout', 5]]