sitano/tiproxy

Inetd-like proxy for a single process

tiproxy

Proxy accepts connections and translates them into the child process. It maintains a single child process when there are active incoming connections.

Quick start

curl+ncat

$ go build 
$ ./tiproxy --dest 127.0.0.1:3000 --exec ncat --workdir /usr/sbin -- -l -k -p 3000 -4 -v
$ curl -v http://127.0.0.1:4000/api

broker-ncat+nc

$ go build 
$ ./tiproxy --dest 127.0.0.1:3000 --exec ncat --workdir /usr/sbin -- -l -k -p 3000 -4 -v --broker
terminal X: $ nc -t 127.0.0.1 4000
terminal Y: $ echo HELLO | nc -t 127.0.0.1 4000
terminal Z: $ telnet 127.0.0.1 4000
terminal Z: > blah [ press ENTER ]

TiDB with docker-compose

$ go build
$ cp tiproxy docker/bin
$ docker build -t tiproxy:latest ./docker
$ docker-compose -f ./docker/docker-compose.yml up 
$ mysql --host 127.0.0.1 --port 4000 -u root
$ mysql --host 127.0.0.1 --port 4000 -u root

Architecture

Client -> Proxy -> Pool -> Resource
  |
  conn ->  get  ->  if ->  exists
                     |       |
  done <----------- conn <---/
                     |
                    else -> spawn \
                     or      |    |
                    wait <---/    |
                     |            |
  done <----------- conn          |
  ...                             |
release -> put       /------------/
            |        |           
  done  <-  *        v (spawn monitor)            
                    ...
                  Monitor Resource
                  timeout and no connections
                     |  ->  kill
                     |       | 
                   killed <- /        
                     |
                    exit

Pool uses sync.Cond to control state transitions between executing coroutines. A calling coroutine processes pool state change. Every new resource has its own controlling monitor that exits as soon as resource disappears.

Pool uses sync.Mutex to control its state. States switch between: closed, opened, starting, shutdown. Pool tracks usage statistics counting connections and keeping the latest change time.

Resource monitor respects SIGCHLD signals.

Proxy uses io.Copy creating 2 coroutines to serve TCP connections 2-way.