sample code for using containerd.

hello-containerd.go

package main

import (
	"context"
	"fmt"
	"log"
	"syscall"
	"time"

	"github.com/containerd/containerd"
	"github.com/containerd/containerd/cio"
	"github.com/containerd/containerd/namespaces"
	"github.com/containerd/containerd/oci"
)

const (
	address = "/run/containerd/containerd.sock"
	alpine  = "docker.io/library/alpine:latest"
)

func main() {
	if err := helloContainerd(); err != nil {
		log.Fatal(err)
	}
}

func helloContainerd() error {
	ctx := namespaces.WithNamespace(context.Background(), "demo")

	// WithNamespace is a placeholder while we get namespace support in the daemon
	client, err := containerd.New(address)
	if err != nil {
		return err
	}
	defer client.Close()

	log.Printf("pulling image %s...\n", alpine)
	// make sure we unpack the image for use after the pull
	image, err := client.Pull(ctx, alpine, containerd.WithPullUnpack)
	if err != nil {
		return err
	}
	log.Println("finished pulling image...")

	id := "hello-containerd1"
	container, err := client.NewContainer(ctx, id, containerd.WithNewSpec(oci.WithImageConfig(image), oci.WithProcessArgs("echo", "Hello containerd")), containerd.WithNewSnapshot(id, image))
	if err != nil {
		return err
	}
	defer container.Delete(ctx)
	log.Println("created new container...")

	// lets get the container's stdio in our current process
	task, err := container.NewTask(ctx, cio.Stdio)
	if err != nil {
		return err
	}
	defer task.Delete(ctx)
	fmt.Printf("container pid %d\n", task.Pid())

	// you can do network namespace setup here or whatever you want without hooks

	if err := task.Start(ctx); err != nil {
		return err
	}

	// let it run for 5 seconds and then kill it
	go func() {
		time.Sleep(5 * time.Second)
		log.Println("killing task...")
		if err := task.Kill(ctx, syscall.SIGTERM); err != nil {
			log.Println(err)
		}
	}()

	status, err := task.Wait(ctx)
	if err != nil {
		return err
	}
	fmt.Printf("task exited with status %d\n", status)

	// all done
	return nil
}