Extract Service struct

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

pkg/service/service.go

@@ -0,0 +1,81 @@
+package service
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"sync"
+	"time"
+
+	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/errdefs"
+	"golang.org/x/sys/unix"
+)
+
+// Remove removes a container
+func Remove(ctx context.Context, client *containerd.Client, name string) error {
+
+	container, containerErr := client.LoadContainer(ctx, name)
+
+	if containerErr == nil {
+		found := true
+		t, err := container.Task(ctx, nil)
+		if err != nil {
+			if errdefs.IsNotFound(err) {
+				found = false
+			} else {
+				return fmt.Errorf("unable to get task %s: ", err)
+			}
+		}
+
+		if found {
+			status, _ := t.Status(ctx)
+			fmt.Printf("Status of %s is: %s\n", name, status.Status)
+
+			log.Printf("Need to kill %s\n", name)
+			err := killTask(ctx, t)
+			if err != nil {
+				return fmt.Errorf("error killing task %s, %s, %s", container.ID(), name, err)
+			}
+		}
+
+		err = container.Delete(ctx, containerd.WithSnapshotCleanup)
+		if err != nil {
+			return fmt.Errorf("error deleting container %s, %s, %s", container.ID(), name, err)
+		}
+	}
+	return nil
+}
+
+// From Stellar
+func killTask(ctx context.Context, task containerd.Task) error {
+	wg := &sync.WaitGroup{}
+	wg.Add(1)
+	var err error
+	go func() {
+		defer wg.Done()
+		if task != nil {
+			wait, err := task.Wait(ctx)
+			if err != nil {
+				err = fmt.Errorf("error waiting on task: %s", err)
+				return
+			}
+			if err := task.Kill(ctx, unix.SIGTERM, containerd.WithKillAll); err != nil {
+				log.Printf("error killing container task: %s", err)
+			}
+			select {
+			case <-wait:
+				task.Delete(ctx)
+				return
+			case <-time.After(5 * time.Second):
+				if err := task.Kill(ctx, unix.SIGKILL, containerd.WithKillAll); err != nil {
+					log.Printf("error force killing container task: %s", err)
+				}
+				return
+			}
+		}
+	}()
+	wg.Wait()
+
+	return err
+}