Running multiple copies of the same module

[danmcclain]

Been really enjoying poking around with gokrazy and was considering the use case of running the same module with different arguments concurrently. I know one option could be "fake" modules (local modules that are thin wrappers)

A more concrete example: I'm running Tailscale up, but also want to run Tailscale serve for another service at the same time

Thanks!

[stapelberg]

I’m glad you’re enjoying gokrazy!

The way I currently deal with running multiple instances is by setting "DontStart": true on the module in question (e.g. the RobustIRC bridge), and then having one or more small wrapper programs that start the desired instances:

package main

import (
	"log"
	"os"
	"os/exec"
	"syscall"
)

func main() {
	bridge := exec.Command("/user/robustirc-bridge", "-network=robustirc.net")
	bridge.Stdout = os.Stdout
	bridge.Stderr = os.Stderr
	bridge.Env = []string{} // clear environment
	bridge.SysProcAttr = &syscall.SysProcAttr{
		Credential: &syscall.Credential{
			Uid: 65534, // nobody
			Gid: 65534, // nogroup
		},
	}
	if err := bridge.Run(); err != nil {
		log.Fatal(err)
	}
}

Note that for tailscale in particular, both tailscale up and tailscale serve are one-time commands that you don’t need to run permanently on an ongoing basis. So you can just enter them interactively once, or have a program that runs them if you’re working on something automated.