tsnet_echo

Example: tsnet Echo

Note

See the top-level Requirements section for pre-requisites.

The same TCP echo server as tcp_echo, but built with the Go-idiomatic tsnet::Server facade instead of the native Config + Device surface. It exists to show the shape a Go tsnet user expects — set the struct's fields, then call a method and let the node start lazily:

// Go tsnet:
srv := &tsnet.Server{Hostname: "tsnet_echo_example", AuthKey: key, Dir: "tsnet_echo_state"}
defer srv.Close()
ln, _ := srv.Listen("tcp", ":1234")

// tailscale-rs tsnet facade (this example):
let mut srv = Server::new();
srv.hostname = Some("tsnet_echo_example".into());
srv.auth_key = Some(key);
srv.dir = Some("tsnet_echo_state".into());
let listener = srv.listen("tcp", ":1234").await?;   // Start() happens lazily on this first call
// … accept connections …
drop(listener);                                     // release the netstack listener before closing
// … srv.close(Some(Duration::from_secs(5))).await;

This example requires the tsnet cargo feature (--features tsnet).

Start the example:

# Terminal 1
$ TS_RS_EXPERIMENT=this_is_unstable_software \
    cargo run --features tsnet --example tsnet_echo -- --auth-key $AUTH_KEY
...
INFO tsnet_echo: listening on the tailnet (press Ctrl-C to shut down) listening_addr=<tailnet IP>:1234
...

Then, in another terminal, connect to it with nc, type a message, and hit enter:

# Terminal 2
$ nc <tailnet IP> 1234
hello, tailscale-rs!
hello, tailscale-rs!

After hitting enter, you should see your message echoed back to you in netcat! Press Ctrl-C in the first terminal to shut the node down gracefully (Go Server.Close).

If you can't connect to the example with netcat, verify the tailnet policy allows your local machine to connect to the example's tailnet IP address on TCP port 1234.

How it maps to Go tsnet.Server

This example	Go tsnet.Server	Notes
srv.hostname = …	Server.Hostname	Requested hostname.
srv.auth_key = …	Server.AuthKey	Also read from TS_AUTH_KEY.
srv.control_url = …	Server.ControlURL	Default control server if unset.
srv.dir = Some(…)	Server.Dir	Persists node identity keys to dir/tailscale-rs.state.
srv.up(timeout)	Server.Up(ctx)	Lazy Start + wait until Running.
srv.tailscale_ips()	Server.TailscaleIPs()	This node's tailnet addresses.
srv.listen("tcp", ":1234")	Server.Listen("tcp", ":1234")	Returns the overlay netstack::TcpListener.
srv.close(timeout)	Server.Close()	Graceful shutdown; consumes the server.

See the crate's tsnet module docs and docs/TSNET_FACADE_DESIGN.md for the full field/method mapping.