rutina

Package Rutina (russian "рутина" - ordinary boring everyday work) is routine orchestrator for your application.

It seems like https://godoc.org/golang.org/x/sync/errgroup with some different:

1. propagates context to every routines. So routine can check if context stopped (ctx.Done()).
2. has flexible run/stop policy. i.e. one routine restarts when it fails (useful on daemons) but if fails another - all routines will be cancelled
3. already has optional signal handler ListenOsSignals()

When it need?

Usually, when your program consists of several routines (i.e.: http server, metrics server and os signals subscriber) and you want to stop all routines when one of them ends (i.e.: by TERM os signal in signal subscriber).

Usage

New instance

r := rutina.New()

or with optional mixins (see below):

r := rutina.New(...Mixins)

or

r.With(...Mixins)

Start new routine

r.Go(func (ctx context.Context) error {
    ...do something...
}, ...runOptions)

Available options of run policy:

• ShutdownIfFail - Shutdown all routines if this routine fails
• RestartIfFail - Restart this routine if it fail
• DoNothingIfFail - Do nothing just stop this routine if it fail
• ShutdownIfDone - Shutdown all routines if this routine done without errors
• RestartIfDone - Restart if this routine done without errors
• DoNothingIfDone - Do nothing if this routine done without errors

Default policy:

ShutdownIfFail && DoNothingIfDone

Example of run policies

r.Go(func(ctx context.Context) error {
	// If this routine produce no error - it just restarts
	// If it returns error - all other routines will shutdown (because context cancels)
}, rutina.RestartIfDone, rutina.ShutdownIfFail)

r.Go(func(ctx context.Context) error {
	// If this routine produce no error - it just completes
	// If it returns error - all other routines will shutdown (because context cancels)
}, rutina.DoNothingIfDone, rutina.ShutdownIfFail)

r.Go(func(ctx context.Context) error {
	// If this routine produce no error - all other routines will shutdown (because context cancels)
	// If it returns error - it will be restarted
}, rutina.RestartIfFail)

r.Go(func(ctx context.Context) error {
	// If this routine stopped by any case - all other routines will shutdown (because context cancels)
}, rutina.ShutdownIfDone)

r.ListenOsSignals() // Shutdown all routines by OS signal

Wait routines to complete

err := r.Wait()

Here err = error that shutdowns all routines (may be will be changed at future)

Mixins

Usage

r := rutina.New(mixin1, mixin2, ...)

or

r := rutina.New()
r = r.With(mixin1, mixin2, ...) // Returns new instance of Rutina!

Logger

r.With(rutina.WithStdLogger())

or

r.With(rutina.WithLogger(logger log.Logger))

Sets standard or custom logger. By default there is no logger.

Custom context

r.With(rutina.WithContext(ctx context.Context))

Propagates your own context to Rutina. By default it use own context.

Example

HTTP server with graceful shutdown example/http_server.go

Different run policies example/policies.go