Lua 过滤器¶

在这个例子中，我们会展示 Lua 过滤器在 Envoy 代理中是如何使用的。 Envoy 代理配置包括一个 Lua 过滤器，此过滤器包含了在这个文档中记录的两个函数，即 envoy_on_request(request_handle) 和 envoy_on_response(response_handle) 。

运行沙盒¶

以下文档说明了上述对于 Envoy 容器编译环境进行设置的过程。

步骤 1：安装 Docker¶

确保你已安装较新版本的 docker 和 docker-compose 。

一个最简单的方法来完成此事就是使用 Docker Desktop 。

步骤 2：克隆 Envoy 仓库¶

如果你还没有克隆 Envoy 仓库，用如下方式进行克隆：

git clone [email protected]:envoyproxy/envoy

git clone https://github.com/envoyproxy/envoy.git

步骤 3：构建沙盒¶

$ pwd
envoy/examples/lua
$ docker-compose pull
$ docker-compose up --build -d
$ docker-compose ps

    Name                     Command               State                            Ports
--------------------------------------------------------------------------------------------------------------------
lua_proxy_1         /docker-entrypoint.sh /bin       Up      10000/tcp, 0.0.0.0:8000->8000/tcp, 0.0.0.0:8001->8001/tcp
lua_web_service_1   node ./index.js                  Up      0.0.0.0:8080->80/tcp

Step 4: 给服务发送请求¶

下面 curl 命令的输出结果应该包含头部 foo 。

终端 1

$ curl -v localhost:8000

   Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 8000 (#0)
> GET / HTTP/1.1
> Host: localhost:8000
> User-Agent: curl/7.64.1
> Accept: */*
>
< HTTP/1.1 200 OK
< x-powered-by: Express
< content-type: application/json; charset=utf-8
< content-length: 544
< etag: W/"220-IhsqVTh4HjcpuJQ3C+rEL1Cw1jA"
< date: Thu, 31 Oct 2019 03:13:24 GMT
< x-envoy-upstream-service-time: 1
< response-body-size: 544                      <-- This is added to the response header by our Lua script. --<
< server: envoy
<
{
  "path": "/",
  "headers": {
    "host": "localhost:8000",
    "user-agent": "curl/7.64.1",
    "accept": "*/*",
    "x-forwarded-proto": "http",
    "x-request-id": "a78fcce7-2d67-4eeb-890a-73eebb942a17",
    "foo": "bar",                              <-- This is added to the request header by our Lua script. --<
    "x-envoy-expected-rq-timeout-ms": "15000",
    "content-length": "0"
  },
  "method": "GET",
  "body": "",
  "fresh": false,
  "hostname": "localhost",
  "ip": "::ffff:172.20.0.2",
  "ips": [],
  "protocol": "http",
  "query": {},
  "subdomains": [],
  "xhr": false,
  "os": {
    "hostname": "7ca39ead805a"
  }
* Connection #0 to host localhost left intact
}* Closing connection 0