Simple process manager helper library, features:

• start processes .AddCommand(Cmd) and .Start(cmdId) or .StartAll(), with environment variables Cmd.Env=[]string{} and Cmd.InheritEnv=true
• stop them; .Kill(cmdId) or .Cleanup() to kill all process
• restart them when they crash; using Cmd.RestartDelayMs=1000 (=1s, default is 0) and Cmd.MaxRestart=5 (restart 5x if process ended/crashed)
• relay termination signals; .Signal(cmdId, os.Kill)
• read their stdout and stderr; Cmd.OnStdout, Cmd.OnStdErr callback
• ability to stop processes when main processes are SIGKILL'ed: .Cleanup() called automatically when main process killed;
• configurable backoff strategy for restarts; you can use Cmd.OnRestart callback to return random delay or implement your own exponential backoff, setting this callback will render Cmd.RestartDelayMs unusable
• Cmd.OnExit callback when no more restart reached, you can call .Start(cmdId) manually again after this
• Cmd.OnProcessCompleted callback each time program completed once (before restarting if MaxRestart not yet reached)
• Cmd.StartDelayMs=1000 (=1s, default is 0) for delaying start, in milliseconds
• Cmd.UseChannelApi=true, if enabled, you can receive from channels: Cmd.StderrChannel, Cmd.OnStdoutChannel, Cmd.ProcessCompletedChannel, Cmd.ExitChannel
• Cmd.LastExecutionError property to get last process execution error, check this answer to get the exit code
• Cmd.OnStateChanged callback and Cmd.StateChangedChannel channel to track process state
• should work on Linux, and probably MacOS and Windows (untested).
• see example/ for other usage example/demo;

daemon := goproc.New()

cmdId := daemon.AddCommand(&goproc.Cmd{
    Program: `sleep`, // program to run
    Parameters: []string{`2`}, // command line arguments
    MaxRestart: goproc.RestartForever, // default: NoRestart=0
    OnStderr: func(cmd *goproc.Cmd, line string) error { // optional
        fmt.Println(`OnStderr: `+line)
        return nil
    },
    OnStdout: func(cmd *goproc.Cmd, line string) error { // optional
        fmt.Println(`OnStdout: `+line)
        return nil
    },
})

daemon.Start(cmdId) // use "go" keyword if you need non-blocking version

• implement .Pause and .Resume API
• comments and documentation in code;
• continuous integration configuration;
• integration tests;
• unit tests.