详细的开发文档：https://docs.konghq.com/2.0.x/plugin-development/
一、背景
今天我们来快速开发一个kong插件，插件的功能是客户端可以传递一个lambda函数，在Kong网关中运行，运行结果会以Header头的形式返回到客户端。
大家可以通过这个插件，来快速的体验PDK提供的函数接口。
二、安装Kong
CentOS系统可以使用下面的命令来完成安装
sudo yum install -y wget
wget https://bintray.com/kong/kong-rpm/rpm -O bintray-kong-kong-rpm.repo
export major_version=`grep -oE '[0-9]+\.[0-9]+' /etc/redhat-release | cut -d "." -f1`
sed -i -e 's/baseurl.*/&\/centos\/'$major_version''/ bintray-kong-kong-rpm.repo
sudo mv bintray-kong-kong-rpm.repo /etc/yum.repos.d/
sudo yum install -y kong
三 启动Kong
- 创建配置文件
cp /etc/kong/kong.conf.default /etc/kong/kong.conf
- 修改配置文件
/etc/kong/kong.conf
sed -i "/^#database/i\database = off" /etc/kong/kong.conf
- 启动kong
kong start
- 查看默认配置
如果访问成功，代表kong已经成功运行
curl http://127.0.0.1:8001/config
四、开发插件
- 进入到kong的插件目录
/usr/local/share/lua/5.1/kong/plugins，创建两个lua文件
cd /usr/local/share/lua/5.1/kong/plugins
mkdir debug
cd debug
cat > schema.lua <<EOF
local typedefs = require "kong.db.schema.typedefs"
return {
name = "debug",
fields = {
{ protocols = typedefs.protocols_http },
{ config = {
type = "record",
fields = {
{ lambda_name = { type = "string", default = "X-Kong-Lambda" }, },
{ result_name = { type = "string", default = "X-Kong-Result" }, },
},
},
},
},
}
EOF
cat > handler.lua <<EOF
local cjson = require("cjson.safe").new()
local DebugHandler = {}
DebugHandler.PRIORITY = 6
DebugHandler.VERSION = "2.0.0"
function DebugHandler:header_filter(conf)
local lambda = kong.request.get_header(conf.lambda_name)
if lambda then
local result = cjson.encode(loadstring(lambda)())
kong.response.set_header(conf.result_name, result)
end
end
EOF
cd
- 自动加载插件，修改配置文件
/etc/kong/kong.conf
sed -i "/^#plugins/i\plugins = bundled,debug" /etc/kong/kong.conf
- 重新启动kong
kong restart
- 修改apis.yaml,配置插件
cd
cat > apis.yml <<EOF
_format_version: "1.1"
services:
- name: httpbin-service
url: http://httpbin.org/
# Entities can store tags as metadata
tags:
- httpbin
# Entities that have a foreign-key relationship can be nested:
routes:
- name: httpbin-route
paths:
- /
plugins:
- name: debug
config:
lambda_name: X-Kong-Lambda
result_name: X-Kong-Result
EOF
- 检测配置文件是否合法
kong config parse apis.yml
- 上传配置文件
curl http://127.0.0.1:8001/config -F "config=@apis.yml"
- 测试接口
# curl -v \
-H "X-Kong-Lambda: return kong.router.get_service().name" \
http://127.0.0.1:8000/ip
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