Kong系列 - 19 - 自定义插件-CentOS

程序员文章站 2022-06-03 21:15:28

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Kong开源了大量的开源插件，当这些开源插件不能满足我们的需求，就需要修改这些开源插件或者自定义插件。Kong提供了方便地自定义插件机制，用户可以开发自己的定制插件。自定义插件可以和Kong进行深层次的集成，如使用数据库表结构，或者扩展Admin API。如果插件实现了所有可选模块，则其目录结构如下所示：

complete-plugin
├── api.lua
├── daos.lua
├── handler.lua
├── migrations
│   ├── init.lua
│   └── 000_base_complete_plugin.lua
└── schema.lua

插件的每个模块对应不同的功能，其中handler.lua和schema.lua是两个必须模块。

Module Name	Required	Description
api.lua	No	插件需要向Admin API暴露接口时使用。
daos.lua	No	数据层相关，当插件需要访问数据库是配置。
handler.lua	Yes	插件的主要逻辑，Kong在不同阶段执行其对应的handler。
migrations/*.lua	No	插件依赖的数据库表结构，启用了daos.lua时需要定义。
schema.lua	Yes	插件的配置参数定义，主要用于Kong参数验证。

可以参考官方开源插件Key Authentication的目录结构。

下面演示如何在Kong加载自定义插件。先准备自定义插件的Lua代码。

mkdir myheader
cd myheader
 
vi handler.lua
local MyHeader = {}
 
MyHeader.PRIORITY = 1000
 
function MyHeader:header_filter(conf)
  -- do custom logic here
  kong.response.set_header("myheader", conf.header_value)
end
 
return MyHeader
 
vi schema.lua
return {
  name = "myheader",
  fields = {
    { config = {
        type = "record",
        fields = {
          { header_value = { type = "string", default = "twingao", }, },
        },
    }, },
  }
}
 
tree myheader/
myheader/
├── handler.lua
└── schema.lua

Kong已经预置了大量的开源插件，这些插件都放在/usr/local/share/lua/5.1/kong/plugins/目录下，我们自定义的插件也可以放到该目录下。

cd /usr/local/share/lua/5.1/kong/plugins/

ls
acl              datadog                      ldap-auth        rate-limiting          syslog
aws-lambda       file-log                     loggly           request-size-limiting  tcp-log
azure-functions  hmac-auth                    log-serializers  request-termination    udp-log
base_plugin.lua  http-log                     oauth2           request-transformer    zipkin
basic-auth       ip-restriction               post-function    response-ratelimiting
bot-detection    jwt                          pre-function     response-transformer
correlation-id   key-auth                     prometheus       session
cors             kubernetes-sidecar-injector  proxy-cache      statsd

mv /root/kong/plugin/myheader/ .

ls
acl              datadog                      ldap-auth        proxy-cache            statsd
aws-lambda       file-log                     loggly           rate-limiting          syslog
azure-functions  hmac-auth                    log-serializers  request-size-limiting  tcp-log
base_plugin.lua  http-log                     myheader         request-termination    udp-log
basic-auth       ip-restriction               oauth2           request-transformer    zipkin
bot-detection    jwt                          post-function    response-ratelimiting
correlation-id   key-auth                     pre-function     response-transformer
cors             kubernetes-sidecar-injector  prometheus       session

kong.conf定义了加载哪些插件，plugins配置项的缺省值是bundled，表示加载官方开源插件，如果要加载自定义插件，去掉注释并在后面跟上自定义插件名称。

vi /etc/kong/kong.conf
#plugins = bundled               # Comma-separated list of plugins this node
                                 # should load. By default, only plugins
                                 # bundled in official distributions are
                                 # loaded via the `bundled` keyword.

改为

plugins = bundled,myheader       # Comma-separated list of plugins this node
                                 # should load. By default, only plugins
                                 # bundled in official distributions are
                                 # loaded via the `bundled` keyword.

查看Kong配置。

kong start

curl http://localhost:8001 -s | python -m json.tool
{
......
        "loaded_plugins": {
            "acl": true,
            "aws-lambda": true,
            "azure-functions": true,
            "basic-auth": true,
            "bot-detection": true,
            "correlation-id": true,
            "cors": true,
            "datadog": true,
            "file-log": true,
            "hmac-auth": true,
            "http-log": true,
            "ip-restriction": true,
            "jwt": true,
            "key-auth": true,
            "kubernetes-sidecar-injector": true,
            "ldap-auth": true,
            "loggly": true,

            "myheader": true,

            "oauth2": true,
            "post-function": true,
            "pre-function": true,
            "prometheus": true,
            "proxy-cache": true,
            "rate-limiting": true,
            "request-size-limiting": true,
            "request-termination": true,
            "request-transformer": true,
            "response-ratelimiting": true,
            "response-transformer": true,
            "session": true,
            "statsd": true,
            "syslog": true,
            "tcp-log": true,
            "udp-log": true,
            "zipkin": true
        },
......
}

测试一下。

curl -X POST \
  --url http://localhost:8001/services/ \
  --data 'name=example-service' \
  --data 'url=http://www.baidu.com' \
  -s | python -m json.tool
{
    "client_certificate": null,
    "connect_timeout": 60000,
    "created_at": 1577356917,
    "host": "www.baidu.com",
    "id": "a658c31d-28f9-49aa-ab74-497beadd0921",
    "name": "example-service",
    "path": null,
    "port": 80,
    "protocol": "http",
    "read_timeout": 60000,
    "retries": 5,
    "tags": null,
    "updated_at": 1577356917,
    "write_timeout": 60000
}

curl -X POST \
  --url http://localhost:8001/services/example-service/routes \
  --data 'name=example-service-route' \
  --data 'paths[]=/foo' \
  -s | python -m json.tool
{
    "created_at": 1577357100,
    "destinations": null,
    "headers": null,
    "hosts": null,
    "https_redirect_status_code": 426,
    "id": "b3190688-0412-4016-85e8-22c96ad26df3",
    "methods": null,
    "name": "example-service-route",
    "paths": [
        "/foo"
    ],
    "preserve_host": false,
    "protocols": [
        "http",
        "https"
    ],
    "regex_priority": 0,
    "service": {
        "id": "a658c31d-28f9-49aa-ab74-497beadd0921"
    },
    "snis": null,
    "sources": null,
    "strip_path": true,
    "tags": null,
    "updated_at": 1577357100
}

curl -i http://localhost:8000/foo
HTTP/1.1 200 OK
Content-Type: text/html; charset=UTF-8
Content-Length: 2381
Connection: keep-alive
Accept-Ranges: bytes
Cache-Control: private, no-cache, no-store, proxy-revalidate, no-transform
Date: Thu, 26 Dec 2019 10:45:41 GMT
Etag: "588604c4-94d"
Last-Modified: Mon, 23 Jan 2017 13:27:32 GMT
Pragma: no-cache
Server: bfe/1.0.8.18
Set-Cookie: BDORZ=27315; max-age=86400; domain=.baidu.com; path=/
X-Kong-Upstream-Latency: 13
X-Kong-Proxy-Latency: 93
Via: kong/1.4.2

<!DOCTYPE html>
<!--STATUS OK--><html> <head><meta http-equiv=content-type content=text/html;charset=utf-8><meta http-equiv=X-UA-Compatible content=IE=Edge><meta content=always name=referrer><link rel=stylesheet type=text/css href=http://s1.bdstatic.com/r/www/cache/bdorz/baidu.min.css><title>百度一下，你就知道</title></head> <body link=#0000cc> <div id=wrapper> <div id=head> <div class=head_wrapper> <div class=s_form> <div class=s_form_wrapper> <div id=lg> <img hidefocus=true src=//www.baidu.com/img/bd_logo1.png width=270 height=129> </div> <form id=form name=f action=//www.baidu.com/s class=fm> <input type=hidden name=bdorz_come value=1> <input type=hidden name=ie value=utf-8> <input type=hidden name=f value=8> <input type=hidden name=rsv_bp value=1> <input type=hidden name=rsv_idx value=1> <input type=hidden name=tn value=baidu><span class="bg s_ipt_wr"><input id=kw name=wd class=s_ipt value maxlength=255 autocomplete=off autofocus></span><span class="bg s_btn_wr"><input type=submit id=su value=百度一下 class="bg s_btn"></span> </form> </div> </div> <div id=u1> <a href=http://news.baidu.com name=tj_trnews class=mnav>新闻</a> <a href=http://www.hao123.com name=tj_trhao123 class=mnav>hao123</a> <a href=http://map.baidu.com name=tj_trmap class=mnav>地图</a> <a href=http://v.baidu.com name=tj_trvideo class=mnav>视频</a> <a href=http://tieba.baidu.com name=tj_trtieba class=mnav>贴吧</a> <noscript> <a href=http://www.baidu.com/bdorz/login.gif?login&amp;tpl=mn&amp;u=http%3A%2F%2Fwww.baidu.com%2f%3fbdorz_come%3d1 name=tj_login class=lb>登录</a> </noscript> <script>document.write('<a href="http://www.baidu.com/bdorz/login.gif?login&tpl=mn&u='+ encodeURIComponent(window.location.href+ (window.location.search === "" ? "?" : "&")+ "bdorz_come=1")+ '" name="tj_login" class="lb">登录</a>');</script> <a href=//www.baidu.com/more/ name=tj_briicon class=bri style="display: block;">更多产品</a> </div> </div> </div> <div id=ftCon> <div id=ftConw> <p id=lh> <a href=http://home.baidu.com>关于百度</a> <a href=http://ir.baidu.com>About Baidu</a> </p> <p id=cp>&copy;2017&nbsp;Baidu&nbsp;<a href=http://www.baidu.com/duty/>使用百度前必读</a>&nbsp; <a href=http://jianyi.baidu.com/ class=cp-feedback>意见反馈</a>&nbsp;京ICP证030173号&nbsp; <img src=//www.baidu.com/img/gs.gif> </p> </div> </div> </div> </body> </html>

curl -X POST \
  --url http://localhost:8001/services/example-service/plugins \
  --data 'name=myheader' \
  -s | python -m json.tool
{
    "config": {
        "header_value": "twingao"
    },
    "consumer": null,
    "created_at": 1577357447,
    "enabled": true,
    "id": "95f27854-ebc5-4797-9023-165d59089e98",
    "name": "myheader",
    "protocols": [
        "grpc",
        "grpcs",
        "http",
        "https"
    ],
    "route": null,
    "run_on": "first",
    "service": {
        "id": "a658c31d-28f9-49aa-ab74-497beadd0921"
    },
    "tags": null
}

curl -i http://localhost:8000/foo
HTTP/1.1 200 OK
Content-Type: text/html; charset=UTF-8
Content-Length: 2381
Connection: keep-alive
Accept-Ranges: bytes
Cache-Control: private, no-cache, no-store, proxy-revalidate, no-transform
Date: Thu, 26 Dec 2019 10:51:21 GMT
Etag: "588604c4-94d"
Last-Modified: Mon, 23 Jan 2017 13:27:32 GMT
Pragma: no-cache
Server: bfe/1.0.8.18
Set-Cookie: BDORZ=27315; max-age=86400; domain=.baidu.com; path=/
myheader: twingao                  ##注意此处
X-Kong-Upstream-Latency: 15
X-Kong-Proxy-Latency: 5
Via: kong/1.4.2

<!DOCTYPE html>
<!--STATUS OK--><html> <head><meta http-equiv=content-type content=text/html;charset=utf-8><meta http-equiv=X-UA-Compatible content=IE=Edge><meta content=always name=referrer><link rel=stylesheet type=text/css href=http://s1.bdstatic.com/r/www/cache/bdorz/baidu.min.css><title>百度一下，你就知道</title></head> <body link=#0000cc> <div id=wrapper> <div id=head> <div class=head_wrapper> <div class=s_form> <div class=s_form_wrapper> <div id=lg> <img hidefocus=true src=//www.baidu.com/img/bd_logo1.png width=270 height=129> </div> <form id=form name=f action=//www.baidu.com/s class=fm> <input type=hidden name=bdorz_come value=1> <input type=hidden name=ie value=utf-8> <input type=hidden name=f value=8> <input type=hidden name=rsv_bp value=1> <input type=hidden name=rsv_idx value=1> <input type=hidden name=tn value=baidu><span class="bg s_ipt_wr"><input id=kw name=wd class=s_ipt value maxlength=255 autocomplete=off autofocus></span><span class="bg s_btn_wr"><input type=submit id=su value=百度一下 class="bg s_btn"></span> </form> </div> </div> <div id=u1> <a href=http://news.baidu.com name=tj_trnews class=mnav>新闻</a> <a href=http://www.hao123.com name=tj_trhao123 class=mnav>hao123</a> <a href=http://map.baidu.com name=tj_trmap class=mnav>地图</a> <a href=http://v.baidu.com name=tj_trvideo class=mnav>视频</a> <a href=http://tieba.baidu.com name=tj_trtieba class=mnav>贴吧</a> <noscript> <a href=http://www.baidu.com/bdorz/login.gif?login&amp;tpl=mn&amp;u=http%3A%2F%2Fwww.baidu.com%2f%3fbdorz_come%3d1 name=tj_login class=lb>登录</a> </noscript> <script>document.write('<a href="http://www.baidu.com/bdorz/login.gif?login&tpl=mn&u='+ encodeURIComponent(window.location.href+ (window.location.search === "" ? "?" : "&")+ "bdorz_come=1")+ '" name="tj_login" class="lb">登录</a>');</script> <a href=//www.baidu.com/more/ name=tj_briicon class=bri style="display: block;">更多产品</a> </div> </div> </div> <div id=ftCon> <div id=ftConw> <p id=lh> <a href=http://home.baidu.com>关于百度</a> <a href=http://ir.baidu.com>About Baidu</a> </p> <p id=cp>&copy;2017&nbsp;Baidu&nbsp;<a href=http://www.baidu.com/duty/>使用百度前必读</a>&nbsp; <a href=http://jianyi.baidu.com/ class=cp-feedback>意见反馈</a>&nbsp;京ICP证030173号&nbsp; <img src=//www.baidu.com/img/gs.gif> </p> </div> </div> </div> </body> </html>

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