distribution/registry/client/repository.go
Clayton Coleman a2015272c1
Support HEAD requests without Docker-Content-Digest header
A statically hosted registry that responds correctly to GET with a
manifest will load the right digest (by looking at the manifest body and
calculating the digest). If the registry returns a HEAD without
`Docker-Content-Digest`, then the client Tags().Get() call will return
an empty digest.

This commit changes the client to fallback to loading the tag via GET if
the `Docker-Content-Digest` header is not set.

Signed-off-by: Clayton Coleman <ccoleman@redhat.com>
2017-08-25 17:18:01 -04:00

854 lines
21 KiB
Go

package client
import (
"bytes"
"context"
"encoding/json"
"errors"
"fmt"
"io"
"io/ioutil"
"net/http"
"net/url"
"strconv"
"strings"
"time"
"github.com/docker/distribution"
"github.com/docker/distribution/reference"
"github.com/docker/distribution/registry/api/v2"
"github.com/docker/distribution/registry/client/transport"
"github.com/docker/distribution/registry/storage/cache"
"github.com/docker/distribution/registry/storage/cache/memory"
"github.com/opencontainers/go-digest"
)
// Registry provides an interface for calling Repositories, which returns a catalog of repositories.
type Registry interface {
Repositories(ctx context.Context, repos []string, last string) (n int, err error)
}
// checkHTTPRedirect is a callback that can manipulate redirected HTTP
// requests. It is used to preserve Accept and Range headers.
func checkHTTPRedirect(req *http.Request, via []*http.Request) error {
if len(via) >= 10 {
return errors.New("stopped after 10 redirects")
}
if len(via) > 0 {
for headerName, headerVals := range via[0].Header {
if headerName != "Accept" && headerName != "Range" {
continue
}
for _, val := range headerVals {
// Don't add to redirected request if redirected
// request already has a header with the same
// name and value.
hasValue := false
for _, existingVal := range req.Header[headerName] {
if existingVal == val {
hasValue = true
break
}
}
if !hasValue {
req.Header.Add(headerName, val)
}
}
}
}
return nil
}
// NewRegistry creates a registry namespace which can be used to get a listing of repositories
func NewRegistry(ctx context.Context, baseURL string, transport http.RoundTripper) (Registry, error) {
ub, err := v2.NewURLBuilderFromString(baseURL, false)
if err != nil {
return nil, err
}
client := &http.Client{
Transport: transport,
Timeout: 1 * time.Minute,
CheckRedirect: checkHTTPRedirect,
}
return &registry{
client: client,
ub: ub,
context: ctx,
}, nil
}
type registry struct {
client *http.Client
ub *v2.URLBuilder
context context.Context
}
// Repositories returns a lexigraphically sorted catalog given a base URL. The 'entries' slice will be filled up to the size
// of the slice, starting at the value provided in 'last'. The number of entries will be returned along with io.EOF if there
// are no more entries
func (r *registry) Repositories(ctx context.Context, entries []string, last string) (int, error) {
var numFilled int
var returnErr error
values := buildCatalogValues(len(entries), last)
u, err := r.ub.BuildCatalogURL(values)
if err != nil {
return 0, err
}
resp, err := r.client.Get(u)
if err != nil {
return 0, err
}
defer resp.Body.Close()
if SuccessStatus(resp.StatusCode) {
var ctlg struct {
Repositories []string `json:"repositories"`
}
decoder := json.NewDecoder(resp.Body)
if err := decoder.Decode(&ctlg); err != nil {
return 0, err
}
for cnt := range ctlg.Repositories {
entries[cnt] = ctlg.Repositories[cnt]
}
numFilled = len(ctlg.Repositories)
link := resp.Header.Get("Link")
if link == "" {
returnErr = io.EOF
}
} else {
return 0, HandleErrorResponse(resp)
}
return numFilled, returnErr
}
// NewRepository creates a new Repository for the given repository name and base URL.
func NewRepository(ctx context.Context, name reference.Named, baseURL string, transport http.RoundTripper) (distribution.Repository, error) {
ub, err := v2.NewURLBuilderFromString(baseURL, false)
if err != nil {
return nil, err
}
client := &http.Client{
Transport: transport,
CheckRedirect: checkHTTPRedirect,
// TODO(dmcgowan): create cookie jar
}
return &repository{
client: client,
ub: ub,
name: name,
context: ctx,
}, nil
}
type repository struct {
client *http.Client
ub *v2.URLBuilder
context context.Context
name reference.Named
}
func (r *repository) Named() reference.Named {
return r.name
}
func (r *repository) Blobs(ctx context.Context) distribution.BlobStore {
statter := &blobStatter{
name: r.name,
ub: r.ub,
client: r.client,
}
return &blobs{
name: r.name,
ub: r.ub,
client: r.client,
statter: cache.NewCachedBlobStatter(memory.NewInMemoryBlobDescriptorCacheProvider(), statter),
}
}
func (r *repository) Manifests(ctx context.Context, options ...distribution.ManifestServiceOption) (distribution.ManifestService, error) {
// todo(richardscothern): options should be sent over the wire
return &manifests{
name: r.name,
ub: r.ub,
client: r.client,
etags: make(map[string]string),
}, nil
}
func (r *repository) Tags(ctx context.Context) distribution.TagService {
return &tags{
client: r.client,
ub: r.ub,
context: r.context,
name: r.Named(),
}
}
// tags implements remote tagging operations.
type tags struct {
client *http.Client
ub *v2.URLBuilder
context context.Context
name reference.Named
}
// All returns all tags
func (t *tags) All(ctx context.Context) ([]string, error) {
var tags []string
u, err := t.ub.BuildTagsURL(t.name)
if err != nil {
return tags, err
}
for {
resp, err := t.client.Get(u)
if err != nil {
return tags, err
}
defer resp.Body.Close()
if SuccessStatus(resp.StatusCode) {
b, err := ioutil.ReadAll(resp.Body)
if err != nil {
return tags, err
}
tagsResponse := struct {
Tags []string `json:"tags"`
}{}
if err := json.Unmarshal(b, &tagsResponse); err != nil {
return tags, err
}
tags = append(tags, tagsResponse.Tags...)
if link := resp.Header.Get("Link"); link != "" {
u = strings.Trim(strings.Split(link, ";")[0], "<>")
} else {
return tags, nil
}
} else {
return tags, HandleErrorResponse(resp)
}
}
}
func descriptorFromResponse(response *http.Response) (distribution.Descriptor, error) {
desc := distribution.Descriptor{}
headers := response.Header
ctHeader := headers.Get("Content-Type")
if ctHeader == "" {
return distribution.Descriptor{}, errors.New("missing or empty Content-Type header")
}
desc.MediaType = ctHeader
digestHeader := headers.Get("Docker-Content-Digest")
if digestHeader == "" {
bytes, err := ioutil.ReadAll(response.Body)
if err != nil {
return distribution.Descriptor{}, err
}
_, desc, err := distribution.UnmarshalManifest(ctHeader, bytes)
if err != nil {
return distribution.Descriptor{}, err
}
return desc, nil
}
dgst, err := digest.Parse(digestHeader)
if err != nil {
return distribution.Descriptor{}, err
}
desc.Digest = dgst
lengthHeader := headers.Get("Content-Length")
if lengthHeader == "" {
return distribution.Descriptor{}, errors.New("missing or empty Content-Length header")
}
length, err := strconv.ParseInt(lengthHeader, 10, 64)
if err != nil {
return distribution.Descriptor{}, err
}
desc.Size = length
return desc, nil
}
// Get issues a HEAD request for a Manifest against its named endpoint in order
// to construct a descriptor for the tag. If the registry doesn't support HEADing
// a manifest, fallback to GET.
func (t *tags) Get(ctx context.Context, tag string) (distribution.Descriptor, error) {
ref, err := reference.WithTag(t.name, tag)
if err != nil {
return distribution.Descriptor{}, err
}
u, err := t.ub.BuildManifestURL(ref)
if err != nil {
return distribution.Descriptor{}, err
}
newRequest := func(method string) (*http.Response, error) {
req, err := http.NewRequest(method, u, nil)
if err != nil {
return nil, err
}
for _, t := range distribution.ManifestMediaTypes() {
req.Header.Add("Accept", t)
}
resp, err := t.client.Do(req)
return resp, err
}
resp, err := newRequest("HEAD")
if err != nil {
return distribution.Descriptor{}, err
}
defer resp.Body.Close()
switch {
case resp.StatusCode >= 200 && resp.StatusCode < 400 && len(resp.Header.Get("Docker-Content-Digest")) > 0:
// if the response is a success AND a Docker-Content-Digest can be retrieved from the headers
return descriptorFromResponse(resp)
default:
// if the response is an error - there will be no body to decode.
// Issue a GET request:
// - for data from a server that does not handle HEAD
// - to get error details in case of a failure
resp, err = newRequest("GET")
if err != nil {
return distribution.Descriptor{}, err
}
defer resp.Body.Close()
if resp.StatusCode >= 200 && resp.StatusCode < 400 {
return descriptorFromResponse(resp)
}
return distribution.Descriptor{}, HandleErrorResponse(resp)
}
}
func (t *tags) Lookup(ctx context.Context, digest distribution.Descriptor) ([]string, error) {
panic("not implemented")
}
func (t *tags) Tag(ctx context.Context, tag string, desc distribution.Descriptor) error {
panic("not implemented")
}
func (t *tags) Untag(ctx context.Context, tag string) error {
panic("not implemented")
}
type manifests struct {
name reference.Named
ub *v2.URLBuilder
client *http.Client
etags map[string]string
}
func (ms *manifests) Exists(ctx context.Context, dgst digest.Digest) (bool, error) {
ref, err := reference.WithDigest(ms.name, dgst)
if err != nil {
return false, err
}
u, err := ms.ub.BuildManifestURL(ref)
if err != nil {
return false, err
}
resp, err := ms.client.Head(u)
if err != nil {
return false, err
}
if SuccessStatus(resp.StatusCode) {
return true, nil
} else if resp.StatusCode == http.StatusNotFound {
return false, nil
}
return false, HandleErrorResponse(resp)
}
// AddEtagToTag allows a client to supply an eTag to Get which will be
// used for a conditional HTTP request. If the eTag matches, a nil manifest
// and ErrManifestNotModified error will be returned. etag is automatically
// quoted when added to this map.
func AddEtagToTag(tag, etag string) distribution.ManifestServiceOption {
return etagOption{tag, etag}
}
type etagOption struct{ tag, etag string }
func (o etagOption) Apply(ms distribution.ManifestService) error {
if ms, ok := ms.(*manifests); ok {
ms.etags[o.tag] = fmt.Sprintf(`"%s"`, o.etag)
return nil
}
return fmt.Errorf("etag options is a client-only option")
}
// ReturnContentDigest allows a client to set a the content digest on
// a successful request from the 'Docker-Content-Digest' header. This
// returned digest is represents the digest which the registry uses
// to refer to the content and can be used to delete the content.
func ReturnContentDigest(dgst *digest.Digest) distribution.ManifestServiceOption {
return contentDigestOption{dgst}
}
type contentDigestOption struct{ digest *digest.Digest }
func (o contentDigestOption) Apply(ms distribution.ManifestService) error {
return nil
}
func (ms *manifests) Get(ctx context.Context, dgst digest.Digest, options ...distribution.ManifestServiceOption) (distribution.Manifest, error) {
var (
digestOrTag string
ref reference.Named
err error
contentDgst *digest.Digest
)
for _, option := range options {
if opt, ok := option.(distribution.WithTagOption); ok {
digestOrTag = opt.Tag
ref, err = reference.WithTag(ms.name, opt.Tag)
if err != nil {
return nil, err
}
} else if opt, ok := option.(contentDigestOption); ok {
contentDgst = opt.digest
} else {
err := option.Apply(ms)
if err != nil {
return nil, err
}
}
}
if digestOrTag == "" {
digestOrTag = dgst.String()
ref, err = reference.WithDigest(ms.name, dgst)
if err != nil {
return nil, err
}
}
u, err := ms.ub.BuildManifestURL(ref)
if err != nil {
return nil, err
}
req, err := http.NewRequest("GET", u, nil)
if err != nil {
return nil, err
}
for _, t := range distribution.ManifestMediaTypes() {
req.Header.Add("Accept", t)
}
if _, ok := ms.etags[digestOrTag]; ok {
req.Header.Set("If-None-Match", ms.etags[digestOrTag])
}
resp, err := ms.client.Do(req)
if err != nil {
return nil, err
}
defer resp.Body.Close()
if resp.StatusCode == http.StatusNotModified {
return nil, distribution.ErrManifestNotModified
} else if SuccessStatus(resp.StatusCode) {
if contentDgst != nil {
dgst, err := digest.Parse(resp.Header.Get("Docker-Content-Digest"))
if err == nil {
*contentDgst = dgst
}
}
mt := resp.Header.Get("Content-Type")
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
return nil, err
}
m, _, err := distribution.UnmarshalManifest(mt, body)
if err != nil {
return nil, err
}
return m, nil
}
return nil, HandleErrorResponse(resp)
}
// Put puts a manifest. A tag can be specified using an options parameter which uses some shared state to hold the
// tag name in order to build the correct upload URL.
func (ms *manifests) Put(ctx context.Context, m distribution.Manifest, options ...distribution.ManifestServiceOption) (digest.Digest, error) {
ref := ms.name
var tagged bool
for _, option := range options {
if opt, ok := option.(distribution.WithTagOption); ok {
var err error
ref, err = reference.WithTag(ref, opt.Tag)
if err != nil {
return "", err
}
tagged = true
} else {
err := option.Apply(ms)
if err != nil {
return "", err
}
}
}
mediaType, p, err := m.Payload()
if err != nil {
return "", err
}
if !tagged {
// generate a canonical digest and Put by digest
_, d, err := distribution.UnmarshalManifest(mediaType, p)
if err != nil {
return "", err
}
ref, err = reference.WithDigest(ref, d.Digest)
if err != nil {
return "", err
}
}
manifestURL, err := ms.ub.BuildManifestURL(ref)
if err != nil {
return "", err
}
putRequest, err := http.NewRequest("PUT", manifestURL, bytes.NewReader(p))
if err != nil {
return "", err
}
putRequest.Header.Set("Content-Type", mediaType)
resp, err := ms.client.Do(putRequest)
if err != nil {
return "", err
}
defer resp.Body.Close()
if SuccessStatus(resp.StatusCode) {
dgstHeader := resp.Header.Get("Docker-Content-Digest")
dgst, err := digest.Parse(dgstHeader)
if err != nil {
return "", err
}
return dgst, nil
}
return "", HandleErrorResponse(resp)
}
func (ms *manifests) Delete(ctx context.Context, dgst digest.Digest) error {
ref, err := reference.WithDigest(ms.name, dgst)
if err != nil {
return err
}
u, err := ms.ub.BuildManifestURL(ref)
if err != nil {
return err
}
req, err := http.NewRequest("DELETE", u, nil)
if err != nil {
return err
}
resp, err := ms.client.Do(req)
if err != nil {
return err
}
defer resp.Body.Close()
if SuccessStatus(resp.StatusCode) {
return nil
}
return HandleErrorResponse(resp)
}
// todo(richardscothern): Restore interface and implementation with merge of #1050
/*func (ms *manifests) Enumerate(ctx context.Context, manifests []distribution.Manifest, last distribution.Manifest) (n int, err error) {
panic("not supported")
}*/
type blobs struct {
name reference.Named
ub *v2.URLBuilder
client *http.Client
statter distribution.BlobDescriptorService
distribution.BlobDeleter
}
func sanitizeLocation(location, base string) (string, error) {
baseURL, err := url.Parse(base)
if err != nil {
return "", err
}
locationURL, err := url.Parse(location)
if err != nil {
return "", err
}
return baseURL.ResolveReference(locationURL).String(), nil
}
func (bs *blobs) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) {
return bs.statter.Stat(ctx, dgst)
}
func (bs *blobs) Get(ctx context.Context, dgst digest.Digest) ([]byte, error) {
reader, err := bs.Open(ctx, dgst)
if err != nil {
return nil, err
}
defer reader.Close()
return ioutil.ReadAll(reader)
}
func (bs *blobs) Open(ctx context.Context, dgst digest.Digest) (distribution.ReadSeekCloser, error) {
ref, err := reference.WithDigest(bs.name, dgst)
if err != nil {
return nil, err
}
blobURL, err := bs.ub.BuildBlobURL(ref)
if err != nil {
return nil, err
}
return transport.NewHTTPReadSeeker(bs.client, blobURL,
func(resp *http.Response) error {
if resp.StatusCode == http.StatusNotFound {
return distribution.ErrBlobUnknown
}
return HandleErrorResponse(resp)
}), nil
}
func (bs *blobs) ServeBlob(ctx context.Context, w http.ResponseWriter, r *http.Request, dgst digest.Digest) error {
panic("not implemented")
}
func (bs *blobs) Put(ctx context.Context, mediaType string, p []byte) (distribution.Descriptor, error) {
writer, err := bs.Create(ctx)
if err != nil {
return distribution.Descriptor{}, err
}
dgstr := digest.Canonical.Digester()
n, err := io.Copy(writer, io.TeeReader(bytes.NewReader(p), dgstr.Hash()))
if err != nil {
return distribution.Descriptor{}, err
}
if n < int64(len(p)) {
return distribution.Descriptor{}, fmt.Errorf("short copy: wrote %d of %d", n, len(p))
}
desc := distribution.Descriptor{
MediaType: mediaType,
Size: int64(len(p)),
Digest: dgstr.Digest(),
}
return writer.Commit(ctx, desc)
}
type optionFunc func(interface{}) error
func (f optionFunc) Apply(v interface{}) error {
return f(v)
}
// WithMountFrom returns a BlobCreateOption which designates that the blob should be
// mounted from the given canonical reference.
func WithMountFrom(ref reference.Canonical) distribution.BlobCreateOption {
return optionFunc(func(v interface{}) error {
opts, ok := v.(*distribution.CreateOptions)
if !ok {
return fmt.Errorf("unexpected options type: %T", v)
}
opts.Mount.ShouldMount = true
opts.Mount.From = ref
return nil
})
}
func (bs *blobs) Create(ctx context.Context, options ...distribution.BlobCreateOption) (distribution.BlobWriter, error) {
var opts distribution.CreateOptions
for _, option := range options {
err := option.Apply(&opts)
if err != nil {
return nil, err
}
}
var values []url.Values
if opts.Mount.ShouldMount {
values = append(values, url.Values{"from": {opts.Mount.From.Name()}, "mount": {opts.Mount.From.Digest().String()}})
}
u, err := bs.ub.BuildBlobUploadURL(bs.name, values...)
if err != nil {
return nil, err
}
resp, err := bs.client.Post(u, "", nil)
if err != nil {
return nil, err
}
defer resp.Body.Close()
switch resp.StatusCode {
case http.StatusCreated:
desc, err := bs.statter.Stat(ctx, opts.Mount.From.Digest())
if err != nil {
return nil, err
}
return nil, distribution.ErrBlobMounted{From: opts.Mount.From, Descriptor: desc}
case http.StatusAccepted:
// TODO(dmcgowan): Check for invalid UUID
uuid := resp.Header.Get("Docker-Upload-UUID")
location, err := sanitizeLocation(resp.Header.Get("Location"), u)
if err != nil {
return nil, err
}
return &httpBlobUpload{
statter: bs.statter,
client: bs.client,
uuid: uuid,
startedAt: time.Now(),
location: location,
}, nil
default:
return nil, HandleErrorResponse(resp)
}
}
func (bs *blobs) Resume(ctx context.Context, id string) (distribution.BlobWriter, error) {
panic("not implemented")
}
func (bs *blobs) Delete(ctx context.Context, dgst digest.Digest) error {
return bs.statter.Clear(ctx, dgst)
}
type blobStatter struct {
name reference.Named
ub *v2.URLBuilder
client *http.Client
}
func (bs *blobStatter) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) {
ref, err := reference.WithDigest(bs.name, dgst)
if err != nil {
return distribution.Descriptor{}, err
}
u, err := bs.ub.BuildBlobURL(ref)
if err != nil {
return distribution.Descriptor{}, err
}
resp, err := bs.client.Head(u)
if err != nil {
return distribution.Descriptor{}, err
}
defer resp.Body.Close()
if SuccessStatus(resp.StatusCode) {
lengthHeader := resp.Header.Get("Content-Length")
if lengthHeader == "" {
return distribution.Descriptor{}, fmt.Errorf("missing content-length header for request: %s", u)
}
length, err := strconv.ParseInt(lengthHeader, 10, 64)
if err != nil {
return distribution.Descriptor{}, fmt.Errorf("error parsing content-length: %v", err)
}
return distribution.Descriptor{
MediaType: resp.Header.Get("Content-Type"),
Size: length,
Digest: dgst,
}, nil
} else if resp.StatusCode == http.StatusNotFound {
return distribution.Descriptor{}, distribution.ErrBlobUnknown
}
return distribution.Descriptor{}, HandleErrorResponse(resp)
}
func buildCatalogValues(maxEntries int, last string) url.Values {
values := url.Values{}
if maxEntries > 0 {
values.Add("n", strconv.Itoa(maxEntries))
}
if last != "" {
values.Add("last", last)
}
return values
}
func (bs *blobStatter) Clear(ctx context.Context, dgst digest.Digest) error {
ref, err := reference.WithDigest(bs.name, dgst)
if err != nil {
return err
}
blobURL, err := bs.ub.BuildBlobURL(ref)
if err != nil {
return err
}
req, err := http.NewRequest("DELETE", blobURL, nil)
if err != nil {
return err
}
resp, err := bs.client.Do(req)
if err != nil {
return err
}
defer resp.Body.Close()
if SuccessStatus(resp.StatusCode) {
return nil
}
return HandleErrorResponse(resp)
}
func (bs *blobStatter) SetDescriptor(ctx context.Context, dgst digest.Digest, desc distribution.Descriptor) error {
return nil
}