FreeSwtich默认的配置体系是XML文件，修改配置后需要reloadxml生效。这对于大型线上系统，是不可接受的。FreeSwitch本身提供了几种不同的动态配置接口，比如mod_xml_curl，本文介绍利用mod_lua动态配置FS的方法。
通过mod_lua模块，你可以利用lua实现动态配置。绑定一个脚本处理XML请求，就像mod_xml_curl那样，动态地把所需要的XML片段喂给FS，指示FS的执行。实现应用与数据的分离。FreeSWITCH需要某种XML信息时，它查询注册的钩子，调用指定的脚本。在脚本中，你可以为所欲为，只是不要忘记返回XML就行了。
配置mod_lua
FreeSwitch启动时会加载conf/autoload_configs/lua.conf.xml配置。
以下是一个极简配置实例：
<configuration name="lua.conf" description="LUA Configuration">
<settings>
<param name="xml-handler-script" value="dp.lua"/>
<param name="xml-handler-bindings" value="dialplan"/>
</settings>
</configuration>
编辑lua.conf.xml之后，FreeSWITCH控制台命令reloadxml不能识别 "xml-handler-script" 参数，你必须重启FS才会生效 FreeSWITCH.
可配置标签
对于"xml-handler-bindings"参数，可配置值有："dialplan" "directory" "configuration" "dialplan|directory|configuration"
- FS会向脚本传递一个XML_REQUEST对象，它包含以下成员：section、tag_name、key_name和key_value。它可用于查询模块配置、目录信息、拨号方案，还可能传递一个'params'属性，携带一个 event对象
- 脚本执行完毕之后，你所设置的XML_STRING对象将返回给FS，无论你在里面设置了什么内容
在Lua脚本中，可以访问XML_REQUEST对象获取必要的信息。比如：
freeswitch.consoleLog("notice", "SECTION " .. XML_REQUEST["section"] .. "\n")模块配置
如果mod_lua加载时有如下配置：
<configuration name="lua.conf" description="LUA Configuration">
<settings>
<param name="xml-handler-script" value="configuration.lua"/>
<param name="xml-handler-bindings" value="configuration"/>
</settings>
</configuration>那么之后加载的模块，可以把mod_lua当成配置服务器，需要配置信息时，调用绑定的lua实时查询。
XML_REQUEST对象，其典型的属性值：
- key_value = 'iax.conf'|'event_socket.conf'|sofia.conf'|...
- key_name = 'name'
- section = 'configuration'
- tag_name = 'configuration'
'params' event object | ||
acl.conf | no | N/A |
event_socket.conf | no | N/A |
post_load_switch.conf | no | N/A |
sofia.conf | yes | |
switch.conf | no | N/A |
syslog.conf | no | N/A |
目录(directory)
启动初始化时
在启动初始化过程中，会读取profile配置，为网关和别名域读取目录信息。
在模块加载时，Lua脚本中的XML_REQUEST对象的属性值：
- key_value = ''
- key_name = ''
- section = 'directory'
- tag_name = ''
此外，"params" 携带一个event 对象。
对sofia中的每个profile，directory都会读取一次。The directory is read once for each profile in the sofia configuration
注意上面的变量值有“空字符串”，不是nil
Params event事件
对于External profile：
Event-Name: REQUEST_PARAMS
Core-UUID: <uuid>
FreeSWITCH-Hostname: hostname
FreeSWITCH-IPv4: 192.168.1.11
FreeSWITCH-IPv6: %3A%3A1
Event-Date-Local: 2010-08-06%2014%3A04%3A40
Event-Date-GMT: Fri,%2006%20Aug%202010%2018%3A04%3A40%20GMT
Event-Date-Timestamp: 1281117880813532
Event-Calling-File: sofia.c
Event-Calling-Function: config_sofia
Event-Calling-Line-Number: 3481
purpose: gateways
profile: external重要字段：
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对于 Internal profile
Event-Name: REQUEST_PARAMS
Core-UUID: <uuid>
FreeSWITCH-Hostname: hostname
FreeSWITCH-IPv4: 192.168.1.11
FreeSWITCH-IPv6: %3A%3A1
Event-Date-Local: 2010-08-06%2014%3A04%3A41
Event-Date-GMT: Fri,%2006%20Aug%202010%2018%3A04%3A41%20GMT
Event-Date-Timestamp: 1281117881174514
Event-Calling-File: sofia.c
Event-Calling-Function: config_sofia
Event-Calling-Line-Number: 3481
purpose: gateways
profile: internal
重要字段：
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网络列表
启动初始化过程中，还会从directory中读取网络列表，但这时的XML_REQUEST属性值有些差异：
- key_value = <name-of-domain> (比如 192.168.1.11)
- key_name = 'name'
- section = 'directory'
- tag_name = 'domain'
Event 报文
Event-Name: REQUEST_PARAMS
Core-UUID: <uuid>
FreeSWITCH-Hostname: hostname
FreeSWITCH-IPv4: 192.168.1.11
FreeSWITCH-IPv6: %3A%3A1
Event-Date-Local: 2010-08-06%2014%3A04%3A43
Event-Date-GMT: Fri,%2006%20Aug%202010%2018%3A04%3A43%20GMT
Event-Date-Timestamp: 1281117883173795
Event-Calling-File: sofia_reg.c
Event-Calling-Function: sofia_reg_parse_auth
Event-Calling-Line-Number: 1797
action: sip_auth
sip_profile: internal
sip_user_agent: IP-Phone-V3.2.49T5.13%20-%20G729
sip_auth_username: 1000
sip_auth_realm: 192.168.1.11
sip_auth_nonce: <auth_nonce_uuid>
sip_auth_uri: sip%3A192.168.1.11
sip_contact_user: 1000
sip_contact_host: 192.168.88.202
sip_to_user: 1000
sip_to_host: 192.168.1.11
sip_to_port: 5060
sip_from_user: 1000
sip_from_host: 192.168.1.11
sip_from_port: 5060
sip_request_host: 192.168.1.11
sip_auth_qop: auth
sip_auth_cnonce: 829326
sip_auth_nc: 00000001
sip_auth_response: <auth_response - md5sum?>
sip_auth_method: REGISTER
key: id
user: 1000
domain: 192.168.1.11
ip: 192.168.88.202重要字段：
|
查找用户
FreeSWITCH以特定域标签查找用户，这时XML_REQUEST对象的属性值：
- key_value = '<name-of-domain>'
- key_name = 'name'
- section = 'directory'
- tag_name = 'domain'
and 'params' will have an event object
注册时(REGISTER)
Event 报文：
Event-Name: REQUEST_PARAMS
Core-UUID: <uuid>
FreeSWITCH-Hostname: hostname
FreeSWITCH-IPv4: 192.168.1.11
FreeSWITCH-IPv6: %3A%3A1
Event-Date-Local: 2010-08-06%2014%3A04%3A43
Event-Date-GMT: Fri,%2006%20Aug%202010%2018%3A04%3A43%20GMT
Event-Date-Timestamp: 1281117883173795
Event-Calling-File: sofia_reg.c
Event-Calling-Function: sofia_reg_parse_auth
Event-Calling-Line-Number: 1797
action: sip_auth
sip_profile: internal
sip_user_agent: IP-Phone-V3.2.49T5.13%20-%20G729
sip_auth_username: 1000
sip_auth_realm: 192.168.1.11
sip_auth_nonce: <auth_nonce_uuid>
sip_auth_uri: sip%3A192.168.1.11
sip_contact_user: 1000
sip_contact_host: 192.168.88.202
sip_to_user: 1000
sip_to_host: 192.168.1.11
sip_to_port: 5060
sip_from_user: 1000
sip_from_host: 192.168.1.11
sip_from_port: 5060
sip_request_host: 192.168.1.11
sip_auth_qop: auth
sip_auth_cnonce: 829326
sip_auth_nc: 00000001
sip_auth_response: <auth_response - md5sum?>
sip_auth_method: REGISTER
key: id
user: 1000
domain: 192.168.1.11
ip: 192.168.88.202重要字段:
|
呼出 (INVITE)
Event 报文
Event-Name: REQUEST_PARAMS
Core-UUID: <uuid>
FreeSWITCH-Hostname: hostname
FreeSWITCH-IPv4: 192.168.1.11
FreeSWITCH-IPv6: %3A%3A1
Event-Date-Local: 2010-08-06%2016%3A28%3A08
Event-Date-GMT: Fri,%2006%20Aug%202010%2020%3A28%3A08%20GMT
Event-Date-Timestamp: 1281126488274011
Event-Calling-File: sofia_reg.c
Event-Calling-Function: sofia_reg_parse_auth
Event-Calling-Line-Number: 1797
action: sip_auth
sip_profile: internal
sip_user_agent: IP-Phone-V3.2.49T5.13%20-%20G729
sip_auth_username: 1001
sip_auth_realm: 192.168.1.11
sip_auth_nonce: 1fe3d1fa-a199-11df-b392-b105e374638e
sip_auth_uri: sip%3A1000%40192.168.1.11
sip_contact_user: 1001
sip_contact_host: 192.168.88.99
sip_to_user: 1000
sip_to_host: 192.168.1.11
sip_to_port: 5060
sip_from_user: 1001
sip_from_host: 192.168.1.11
sip_from_port: 5060
sip_request_user: 1000
sip_request_host: 192.168.1.11
sip_auth_qop: auth
sip_auth_cnonce: 10560d0
sip_auth_nc: 00000001
sip_auth_response: b99d1213022480a2b6c4e14432661821
sip_auth_method: INVITE
key: id
user: 1001
domain: 192.168.1.11
ip: 192.168.88.99重要字段:
|
呼入
Event 报文
Event-Name: REQUEST_PARAMS
Core-UUID: <uuid>
FreeSWITCH-Hostname: hostname
FreeSWITCH-IPv4: 192.168.1.11
FreeSWITCH-IPv6: %3A%3A1
Event-Date-Local: 2010-08-06%2016%3A28%3A09
Event-Date-GMT: Fri,%2006%20Aug%202010%2020%3A28%3A09%20GMT
Event-Date-Timestamp: 1281126489462522
Event-Calling-File: mod_dptools.c
Event-Calling-Function: user_outgoing_channel
Event-Calling-Line-Number: 2662
as_channel: true
action: user_call
key: id
user: 1000
domain: 192.168.1.11重要字段:
|
拨号方案
配置
<configuration name="lua.conf" description="LUA Configuration">
<settings>
<param name="xml-handler-script" value="dp.lua"/>
<param name="xml-handler-bindings" value="dialplan"/>
</settings>
</configuration>Lua 脚本 dp.lua示例
-- params is the event passed into us we can use params:getHeader to grab things we want.
io.write("TEST\n" .. params:serialize("xml") .. "\n");
mydialplan = [[
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<document type="freeswitch/xml">
<section name="dialplan" description="LUA Dial Plan For FreeSwitch">
<context name="default">
<extension name="lua_dp_ext">
<condition field="destination_number" expression="^10086$">
<action application="sleep" data="1000 "/>
<action application="answer"/>
<action application="playback" data="ivr/8000/ivr-welcome_to_freeswitch.wav"/>
</condition>
</extension>
</context>
</section>
</document>
]]
XML_STRING = mydialplan
-- comment the following line for production:
freeswitch.consoleLog("notice", "Debug XML:\n" .. XML_STRING .. "\n")同一功能的另一个版本：
-- LUA dialplan
DIALPLAN = {}
freeswitch.consoleLog("notice", "SECTION " .. XML_REQUEST["section"] .. "\n")
table.insert(DIALPLAN, [[<?xml version="1.0" encoding="UTF-8" standalone="no"?>]])
table.insert(DIALPLAN, [[<document type="freeswitch/xml">]])
table.insert(DIALPLAN, [[ <section name="dialplan" description="LUA Dial Plan For FreeSwitch">]])
table.insert(DIALPLAN, [[ <context name="default">]])
table.insert(DIALPLAN, [[ <extension name="lua_dp_ext">o]])
table.insert(DIALPLAN, [[ <condition field="destination_number" expression="^10086$">]])
table.insert(DIALPLAN, [[ <action application="sleep" data="1000 "/>]])
table.insert(DIALPLAN, [[ <action application="answer"/>]])
table.insert(DIALPLAN, [[ <action application="playback" data="ivr/8000/ivr-welcome_to_freeswitch.wav"/>]])
table.insert(DIALPLAN, [[ </condition>]])
table.insert(DIALPLAN, [[ </extension>]])
table.insert(DIALPLAN, [[ </context>]])
table.insert(DIALPLAN, [[ </section>]])
table.insert(DIALPLAN, [[</document>]])
XML_STRING = table.concat(DIALPLAN, "\n")
mydialplan = [[
<document type="freeswitch/xml">
<section name="dialplan" description="LUA Dial Plan For FreeSwitch">
<context name="default">
<extension name="lua_dp_ext">
<condition field="destination_number" expression="^10086$">
<action application="sleep" data="1000 "/>
<action application="answer"/>
<action application="playback" data="ivr/8000/ivr-welcome_to_freeswitch.wav"/>
</condition>
</extension>
</context>
</section>
</document>
]]
-- comment the following line for production:
freeswitch.consoleLog("notice", "Debug XML:\n" .. XML_STRING .. "\n")
通过profile设置跳转
上述实例，展示了lua是怎样生成XML片段并喂给FS执行的。但是拼接XML的过程显得有些繁琐。有没有办法简单一点呢？Dialplan的描述本质上无非就是一组的Action加上参数而已。
lua_dialplan_hunt的实现中，允许使用ACTIONS表来传递这些信息，换句话说，在脚本里，构建一个ACTIONS table并传回给FS就可以了。那么我们需要怎样做呢？
profile设置
编辑sip profile配置文件，比如说freeswitch/sip_profiles/internal.xml，修改以下两个属性：
<param name="context" value="luadp.lua"/>
<param name="dialplan" value="LUA"/>用户目录配置
修改用户的context属性为“luadp.lua”，比如说freeswitch/directory/default/1000.xml：
<variable name="user_context" value="luadp.lua"/>添加lua脚本
在脚本目录下，添加一个名为luadp.lua的脚本，内容如下：
-- LUA dialplan
ACTIONS = {}
freeswitch.consoleLog("notice", "from your script")
table.insert(ACTIONS, {"sleep", "1000"})
table.insert(ACTIONS, "answer")
table.insert(ACTIONS, {"playback", "ivr/8000/ivr-welcome_to_freeswitch.wav"})
table.insert(ACTIONS, {"log", "NOTICE after your script"})这个实例是前面dialplan的第三个版本，脚本逻辑是不是简单得多了。
Lua调用XML dialplan:
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XML 调用Lua dialplan:
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Not found
如果LUA 收到一个dialplan查询请求，但没有相应处理逻辑，那么应当返回 "not found" 结果（如下所示），不能返回空串：
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<document type="freeswitch/xml">
<section name="result">
<result status="not found" />
</section>
</document>如果返回一个空串，FS将处理报错：
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