containerd/cmd/dist/fetch.go
Derek McGowan 9f90d8a9b4
Add schema1 conversion on pull
closes #851

Signed-off-by: Derek McGowan <derek@mcgstyle.net>
2017-06-14 10:07:39 -07:00

307 lines
7.3 KiB
Go

package main
import (
"context"
"fmt"
"io"
"os"
"sync"
"text/tabwriter"
"time"
"github.com/containerd/containerd"
"github.com/containerd/containerd/content"
"github.com/containerd/containerd/images"
"github.com/containerd/containerd/log"
"github.com/containerd/containerd/progress"
"github.com/containerd/containerd/remotes"
digest "github.com/opencontainers/go-digest"
ocispec "github.com/opencontainers/image-spec/specs-go/v1"
"github.com/urfave/cli"
)
var fetchCommand = cli.Command{
Name: "fetch",
Usage: "fetch all content for an image into containerd",
ArgsUsage: "[flags] <remote> <object>",
Description: `Fetch an image into containerd.
This command ensures that containerd has all the necessary resources to build
an image's rootfs and convert the configuration to a runtime format supported
by containerd.
This command uses the same syntax, of remote and object, as 'dist
fetch-object'. We may want to make this nicer, but agnostism is preferred for
the moment.
Right now, the responsibility of the daemon and the cli aren't quite clear. Do
not use this implementation as a guide. The end goal should be having metadata,
content and snapshots ready for a direct use via the 'ctr run'.
Most of this is experimental and there are few leaps to make this work.`,
Flags: registryFlags,
Action: func(clicontext *cli.Context) error {
var (
ref = clicontext.Args().First()
)
ctx, cancel := appContext(clicontext)
defer cancel()
_, err := fetch(ctx, ref, clicontext)
return err
},
}
func fetch(ctx context.Context, ref string, clicontext *cli.Context) (containerd.Image, error) {
client, err := getClient(clicontext)
if err != nil {
return nil, err
}
resolver, err := getResolver(ctx, clicontext)
if err != nil {
return nil, err
}
ongoing := newJobs(ref)
pctx, stopProgress := context.WithCancel(ctx)
progress := make(chan struct{})
go func() {
showProgress(pctx, ongoing, client.ContentStore(), os.Stdout)
close(progress)
}()
h := images.HandlerFunc(func(ctx context.Context, desc ocispec.Descriptor) ([]ocispec.Descriptor, error) {
if desc.MediaType != images.MediaTypeDockerSchema1Manifest {
ongoing.add(desc)
}
return nil, nil
})
log.G(pctx).WithField("image", ref).Debug("fetching")
img, err := client.Pull(pctx, ref, containerd.WithResolver(resolver), containerd.WithImageHandler(h), containerd.WithSchema1Conversion)
stopProgress()
if err != nil {
return nil, err
}
<-progress
return img, nil
}
func showProgress(ctx context.Context, ongoing *jobs, cs content.Store, out io.Writer) {
var (
ticker = time.NewTicker(100 * time.Millisecond)
fw = progress.NewWriter(out)
start = time.Now()
statuses = map[string]statusInfo{}
done bool
)
defer ticker.Stop()
outer:
for {
select {
case <-ticker.C:
fw.Flush()
tw := tabwriter.NewWriter(fw, 1, 8, 1, ' ', 0)
resolved := "resolved"
if !ongoing.isResolved() {
resolved = "resolving"
}
statuses[ongoing.name] = statusInfo{
Ref: ongoing.name,
Status: resolved,
}
keys := []string{ongoing.name}
activeSeen := map[string]struct{}{}
if !done {
active, err := cs.Status(ctx, "")
if err != nil {
log.G(ctx).WithError(err).Error("active check failed")
continue
}
// update status of active entries!
for _, active := range active {
statuses[active.Ref] = statusInfo{
Ref: active.Ref,
Status: "downloading",
Offset: active.Offset,
Total: active.Total,
StartedAt: active.StartedAt,
UpdatedAt: active.UpdatedAt,
}
activeSeen[active.Ref] = struct{}{}
}
}
// now, update the items in jobs that are not in active
for _, j := range ongoing.jobs() {
key := remotes.MakeRefKey(ctx, j)
keys = append(keys, key)
if _, ok := activeSeen[key]; ok {
continue
}
status, ok := statuses[key]
if !done && (!ok || status.Status == "downloading") {
info, err := cs.Info(ctx, j.Digest)
if err != nil {
if !content.IsNotFound(err) {
log.G(ctx).WithError(err).Errorf("failed to get content info")
continue outer
} else {
statuses[key] = statusInfo{
Ref: key,
Status: "waiting",
}
}
} else if info.CommittedAt.After(start) {
statuses[key] = statusInfo{
Ref: key,
Status: "done",
Offset: info.Size,
Total: info.Size,
UpdatedAt: info.CommittedAt,
}
} else {
statuses[key] = statusInfo{
Ref: key,
Status: "exists",
}
}
} else if done {
if ok {
if status.Status != "done" && status.Status != "exists" {
status.Status = "done"
statuses[key] = status
}
} else {
statuses[key] = statusInfo{
Ref: key,
Status: "done",
}
}
}
}
var ordered []statusInfo
for _, key := range keys {
ordered = append(ordered, statuses[key])
}
display(tw, ordered, start)
tw.Flush()
if done {
fw.Flush()
return
}
case <-ctx.Done():
done = true // allow ui to update once more
}
}
}
// jobs provides a way of identifying the download keys for a particular task
// encountering during the pull walk.
//
// This is very minimal and will probably be replaced with something more
// featured.
type jobs struct {
name string
added map[digest.Digest]struct{}
descs []ocispec.Descriptor
mu sync.Mutex
resolved bool
}
func newJobs(name string) *jobs {
return &jobs{
name: name,
added: map[digest.Digest]struct{}{},
}
}
func (j *jobs) add(desc ocispec.Descriptor) {
j.mu.Lock()
defer j.mu.Unlock()
j.resolved = true
if _, ok := j.added[desc.Digest]; ok {
return
}
j.descs = append(j.descs, desc)
j.added[desc.Digest] = struct{}{}
}
func (j *jobs) jobs() []ocispec.Descriptor {
j.mu.Lock()
defer j.mu.Unlock()
var descs []ocispec.Descriptor
return append(descs, j.descs...)
}
func (j *jobs) isResolved() bool {
j.mu.Lock()
defer j.mu.Unlock()
return j.resolved
}
type statusInfo struct {
Ref string
Status string
Offset int64
Total int64
StartedAt time.Time
UpdatedAt time.Time
}
func display(w io.Writer, statuses []statusInfo, start time.Time) {
var total int64
for _, status := range statuses {
total += status.Offset
switch status.Status {
case "downloading", "uploading":
var bar progress.Bar
if status.Total > 0.0 {
bar = progress.Bar(float64(status.Offset) / float64(status.Total))
}
fmt.Fprintf(w, "%s:\t%s\t%40r\t%8.8s/%s\t\n",
status.Ref,
status.Status,
bar,
progress.Bytes(status.Offset), progress.Bytes(status.Total))
case "resolving", "waiting":
bar := progress.Bar(0.0)
fmt.Fprintf(w, "%s:\t%s\t%40r\t\n",
status.Ref,
status.Status,
bar)
default:
bar := progress.Bar(1.0)
fmt.Fprintf(w, "%s:\t%s\t%40r\t\n",
status.Ref,
status.Status,
bar)
}
}
fmt.Fprintf(w, "elapsed: %-4.1fs\ttotal: %7.6v\t(%v)\t\n",
time.Since(start).Seconds(),
// TODO(stevvooe): These calculations are actually way off.
// Need to account for previously downloaded data. These
// will basically be right for a download the first time
// but will be skewed if restarting, as it includes the
// data into the start time before.
progress.Bytes(total),
progress.NewBytesPerSecond(total, time.Since(start)))
}