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crosbymichael/main.go

Created October 3, 2019 20:23
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  1. crosbymichael created this gist Oct 3, 2019.
    87 changes: 87 additions & 0 deletions main.go
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,87 @@
    package main

    import (
    "context"
    "syscall"
    "time"

    "github.com/Sirupsen/logrus"
    "github.com/containerd/containerd"
    "github.com/containerd/containerd/cio"
    "github.com/containerd/containerd/namespaces"
    "github.com/containerd/containerd/oci"
    "github.com/crosbymichael/volumes"
    )

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

    func main() {
    ctx := context.Background()
    // name your own namespace
    ctx = namespaces.WithNamespace(ctx, "mystuff")
    if err := runRedis(ctx, "redis"); err != nil {
    logrus.Error(err)
    }
    }

    func runRedis(ctx context.Context, id string) error {
    client, err := containerd.New(address)
    if err != nil {
    return err
    }
    defer client.Close()

    var (
    target = "/tmp/redis"
    volume = volumes.NewBindVolume(target, volumes.WithOptions([]string{"rw"}))
    )

    image, err := client.Pull(ctx, redis)
    if err != nil {
    return err
    }
    if err := image.UnpackTo(ctx, volumes.WithVolumeUnpack(volume)); err != nil {
    return err
    }
    container, err := client.NewContainer(
    ctx,
    id,
    containerd.WithNewSnapshot(id, image),
    // need to hack around withimageconfig because it uses the fs and snapshotters for
    // getting additional guids and usernames
    containerd.WithNewSpec(oci.WithRootFSPath(target), oci.WithImageConfig(image), oci.WithRootFSPath("rootfs")),
    )
    if err != nil {
    return err
    }
    // delete the snapshot with the container
    defer container.Delete(ctx)

    // use our stdio for the container's stdio
    task, err := container.NewTask(ctx, cio.NewCreator(cio.WithStdio), volumes.WithVolume(volume))
    if err != nil {
    return err
    }
    // get the exit channel
    exit, err := task.Wait(ctx)
    if err != nil {
    return err
    }
    defer task.Delete(ctx)

    // start the task
    if err := task.Start(ctx); err != nil {
    return err
    }
    // for the example run for 3 sec then kill the redis container
    time.Sleep(30 * time.Second)
    if err := task.Kill(ctx, syscall.SIGTERM); err != nil {
    return err
    }
    // wait for the task to exit
    <-exit
    return nil
    }