with_cancel.go

package main

import (
	"context"
	"fmt"
	"time"
)

func consume(ctx context.Context, partition int) {

	for {
		select {
		case <-ctx.Done():
			fmt.Println("I am done")
			break
		default:
			fmt.Printf("consuming from parition: %d\n", partition)
			time.Sleep(1 * time.Second)
		}
	}
}

func main() {
	ctx, cancel := context.WithCancel(context.Background())

	for i := 0; i < 5; i++ {
		go consume(ctx, i)
	}

	time.Sleep(5 * time.Second)

	cancel()
}