kevwan / tproxy

A cli tool to proxy and analyze TCP connections.

tproxy

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Why I wrote this tool

When I develop backend services and write go-zero, I often need to monitor the network traffic. For example:

1. monitoring gRPC connections, when to connect and when to reconnect
2. monitoring MySQL connection pools, how many connections and figure out the lifetime policy
3. monitoring any TCP connections on the fly

Installation

$ go install github.com/kevwan/tproxy@latest

Or use docker images:

$ docker run --rm -it -p <listen-port>:<listen-port> -p <remote-port>:<remote-port> kevinwan/tproxy:v1 tproxy -l 0.0.0.0 -p <listen-port> -r host.docker.internal:<remote-port>

For arm64:

$ docker run --rm -it -p <listen-port>:<listen-port> -p <remote-port>:<remote-port> kevinwan/tproxy:v1-arm64 tproxy -l 0.0.0.0 -p <listen-port> -r host.docker.internal:<remote-port>

On Windows, you can use scoop:

$ scoop install tproxy

Usages

$ tproxy --help
Usage of tproxy:
  -d duration
    	the delay to relay packets
  -down int
    	Downward speed limit(bytes/second)
  -l string
    	Local address to listen on (default "localhost")
  -p int
    	Local port to listen on, default to pick a random port
  -q	Quiet mode, only prints connection open/close and stats, default false
  -r string
    	Remote address (host:port) to connect
  -s	Enable statistics
  -t string
    	The type of protocol, currently support http2, grpc, redis and mongodb
  -up int
    	Upward speed limit(bytes/second)

Examples

Monitor gRPC connections

$ tproxy -p 8088 -r localhost:8081 -t grpc -d 100ms

• listen on localhost and port 8088
• redirect the traffic to localhost:8081
• protocol type to be gRPC
• delay 100ms for each packets

Monitor MySQL connections

$ tproxy -p 3307 -r localhost:3306

Check the connection reliability (Retrans rate and RTT)

$ tproxy -p 3307 -r remotehost:3306 -s -q

Learn the connection pool behaviors

$ tproxy -p 3307 -r localhost:3306 -q -s

Give a Star! ⭐

If you like or are using this project, please give it a star. Thanks!

tproxy's Issues

Failed to start listener

Hi,
I just ran this command tproxy -p 3307 -r localhost:3306 and always get this output:
[x] Failed to start listener: failed to start listener: listen tcp: lookup localhost: no such host
I changed localhost to 127.0.0.1 but it still failed.

Is there a loop in the command?

I'm new to Docker and I'm confused when I try to understand the command

docker run --rm -it -p <listen-port>:<listen-port> -p <remote-port>:<remote-port> kevinwan/tproxy:v1 tproxy -l 0.0.0.0 -p <listen-port> -r host.docker.internal:<remote-port>

I'm gonna split the command into 2 parts:

1. docker run --rm -it -p <listen-port>:<listen-port> -p <remote-port>:<remote-port> kevinwan/tproxy:v1: The flag -p map 2 ports of the host to the container, that't alright;
2. tproxy -l 0.0.0.0 -p <listen-port> -r host.docker.internal:<remote-port>: The -r host.docker.internal:<remote-port> part cause the container access the host port directly, which I think may cause a loop like this:

Could you please help me to figure it out?

Why it's not responding when I connect to mysql?

arm64框架，监听mysql，开了个服务调用

Nats msg bus

Hi,
what about to support/use Nats for the tcp proxy forwarding ?
Whit this approach it could be very easy to monitor the tcp traffic.

Bye,
Luca

slice bounds out of range

.