cache backend for github actions

cache/remotecache/gha/gha.go

@@ -0,0 +1,347 @@
+package gha
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"github.com/containerd/containerd/content"
+	"github.com/moby/buildkit/cache/remotecache"
+	v1 "github.com/moby/buildkit/cache/remotecache/v1"
+	"github.com/moby/buildkit/session"
+	"github.com/moby/buildkit/solver"
+	"github.com/moby/buildkit/util/progress"
+	"github.com/moby/buildkit/worker"
+	"github.com/opencontainers/go-digest"
+	specs "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	actionscache "github.com/tonistiigi/go-actions-cache"
+	"golang.org/x/sync/errgroup"
+)
+
+func init() {
+	actionscache.Log = logrus.Debugf
+}
+
+const (
+	attrScope = "scope"
+	attrToken = "token"
+	attrURL   = "url"
+	version   = "1"
+)
+
+type Config struct {
+	Scope string
+	URL   string
+	Token string
+}
+
+func getConfig(attrs map[string]string) (*Config, error) {
+	scope, ok := attrs[attrScope]
+	if !ok {
+		scope = "buildkit"
+	}
+	url, ok := attrs[attrURL]
+	if !ok {
+		return nil, errors.Errorf("url not set for github actions cache")
+	}
+	token, ok := attrs[attrToken]
+	if !ok {
+		return nil, errors.Errorf("token not set for github actions cache")
+	}
+	return &Config{
+		Scope: scope,
+		URL:   url,
+		Token: token,
+	}, nil
+}
+
+// ResolveCacheExporterFunc for Github actions cache exporter.
+func ResolveCacheExporterFunc() remotecache.ResolveCacheExporterFunc {
+	return func(ctx context.Context, g session.Group, attrs map[string]string) (remotecache.Exporter, error) {
+		cfg, err := getConfig(attrs)
+		if err != nil {
+			return nil, err
+		}
+		return NewExporter(cfg)
+	}
+}
+
+type exporter struct {
+	solver.CacheExporterTarget
+	chains *v1.CacheChains
+	cache  *actionscache.Cache
+	config *Config
+}
+
+func NewExporter(c *Config) (remotecache.Exporter, error) {
+	cc := v1.NewCacheChains()
+	cache, err := actionscache.New(c.Token, c.URL)
+	if err != nil {
+		return nil, err
+	}
+	return &exporter{CacheExporterTarget: cc, chains: cc, cache: cache, config: c}, nil
+}
+
+func (ce *exporter) blobKey(dgst digest.Digest) string {
+	return "buildkit-blob-" + version + "-" + dgst.String()
+}
+
+func (ce *exporter) indexKey() string {
+	scope := ""
+	for _, s := range ce.cache.Scopes() {
+		if s.Permission&actionscache.PermissionWrite != 0 {
+			scope = s.Scope
+		}
+	}
+	scope = digest.FromBytes([]byte(scope)).Hex()[:8]
+	return "index-" + ce.config.Scope + "-" + version + "-" + scope
+}
+
+func (ce *exporter) Finalize(ctx context.Context) (map[string]string, error) {
+	// res := make(map[string]string)
+	config, descs, err := ce.chains.Marshal()
+	if err != nil {
+		return nil, err
+	}
+
+	// TODO: push parallel
+	for i, l := range config.Layers {
+		dgstPair, ok := descs[l.Blob]
+		if !ok {
+			return nil, errors.Errorf("missing blob %s", l.Blob)
+		}
+		if dgstPair.Descriptor.Annotations == nil {
+			return nil, errors.Errorf("invalid descriptor without annotations")
+		}
+		var diffID digest.Digest
+		v, ok := dgstPair.Descriptor.Annotations["containerd.io/uncompressed"]
+		if !ok {
+			return nil, errors.Errorf("invalid descriptor without uncompressed annotation")
+		}
+		dgst, err := digest.Parse(v)
+		if err != nil {
+			return nil, errors.Wrapf(err, "failed to parse uncompressed annotation")
+		}
+		diffID = dgst
+
+		key := ce.blobKey(dgstPair.Descriptor.Digest)
+		b, err := ce.cache.Load(ctx, key)
+		if err != nil {
+			return nil, err
+		}
+		if b == nil {
+			layerDone := oneOffProgress(ctx, fmt.Sprintf("writing layer %s", l.Blob))
+			ra, err := dgstPair.Provider.ReaderAt(ctx, dgstPair.Descriptor)
+			if err != nil {
+				return nil, layerDone(err)
+			}
+			if err := ce.cache.Save(ctx, key, ra); err != nil {
+				return nil, layerDone(errors.Wrap(err, "error writing layer blob"))
+			}
+			layerDone(nil)
+		}
+		la := &v1.LayerAnnotations{
+			DiffID:    diffID,
+			Size:      dgstPair.Descriptor.Size,
+			MediaType: dgstPair.Descriptor.MediaType,
+		}
+		if v, ok := dgstPair.Descriptor.Annotations["buildkit/createdat"]; ok {
+			var t time.Time
+			if err := (&t).UnmarshalText([]byte(v)); err != nil {
+				return nil, err
+			}
+			la.CreatedAt = t.UTC()
+		}
+		config.Layers[i].Annotations = la
+	}
+
+	dt, err := json.Marshal(config)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := ce.cache.SaveMutable(ctx, ce.indexKey(), 15*time.Second, func(old *actionscache.Entry) (actionscache.Blob, error) {
+		return actionscache.NewBlob(dt), nil
+	}); err != nil {
+		return nil, err
+	}
+
+	return nil, nil
+}
+
+// ResolveCacheImporterFunc for Github actions cache importer.
+func ResolveCacheImporterFunc() remotecache.ResolveCacheImporterFunc {
+	return func(ctx context.Context, g session.Group, attrs map[string]string) (remotecache.Importer, specs.Descriptor, error) {
+		cfg, err := getConfig(attrs)
+		if err != nil {
+			return nil, specs.Descriptor{}, err
+		}
+		i, err := NewImporter(cfg)
+		if err != nil {
+			return nil, specs.Descriptor{}, err
+		}
+		return i, specs.Descriptor{}, nil
+	}
+}
+
+type importer struct {
+	cache  *actionscache.Cache
+	config *Config
+}
+
+func NewImporter(c *Config) (remotecache.Importer, error) {
+	cache, err := actionscache.New(c.Token, c.URL)
+	if err != nil {
+		return nil, err
+	}
+	return &importer{cache: cache, config: c}, nil
+}
+
+func (ci *importer) makeDescriptorProviderPair(l v1.CacheLayer) (*v1.DescriptorProviderPair, error) {
+	if l.Annotations == nil {
+		return nil, errors.Errorf("cache layer with missing annotations")
+	}
+	annotations := map[string]string{}
+	if l.Annotations.DiffID == "" {
+		return nil, errors.Errorf("cache layer with missing diffid")
+	}
+	annotations["containerd.io/uncompressed"] = l.Annotations.DiffID.String()
+	if !l.Annotations.CreatedAt.IsZero() {
+		txt, err := l.Annotations.CreatedAt.MarshalText()
+		if err != nil {
+			return nil, err
+		}
+		annotations["buildkit/createdat"] = string(txt)
+	}
+	desc := specs.Descriptor{
+		MediaType:   l.Annotations.MediaType,
+		Digest:      l.Blob,
+		Size:        l.Annotations.Size,
+		Annotations: annotations,
+	}
+	return &v1.DescriptorProviderPair{
+		Descriptor: desc,
+		Provider:   &ciProvider{desc: desc, ci: ci},
+	}, nil
+}
+
+func (ci *importer) loadScope(ctx context.Context, scope string) (*v1.CacheChains, error) {
+	scope = digest.FromBytes([]byte(scope)).Hex()[:8]
+	key := "index-" + ci.config.Scope + "-" + version + "-" + scope
+
+	entry, err := ci.cache.Load(ctx, key)
+	if err != nil {
+		return nil, err
+	}
+	if entry == nil {
+		return v1.NewCacheChains(), nil
+	}
+
+	// TODO: this buffer can be removed
+	buf := &bytes.Buffer{}
+	if err := entry.WriteTo(ctx, buf); err != nil {
+		return nil, err
+	}
+
+	var config v1.CacheConfig
+	if err := json.Unmarshal(buf.Bytes(), &config); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	allLayers := v1.DescriptorProvider{}
+
+	for _, l := range config.Layers {
+		dpp, err := ci.makeDescriptorProviderPair(l)
+		if err != nil {
+			return nil, err
+		}
+		allLayers[l.Blob] = *dpp
+	}
+
+	cc := v1.NewCacheChains()
+	if err := v1.ParseConfig(config, allLayers, cc); err != nil {
+		return nil, err
+	}
+	return cc, nil
+}
+
+func (ci *importer) Resolve(ctx context.Context, _ specs.Descriptor, id string, w worker.Worker) (solver.CacheManager, error) {
+	eg, ctx := errgroup.WithContext(ctx)
+	ccs := make([]*v1.CacheChains, len(ci.cache.Scopes()))
+
+	for i, s := range ci.cache.Scopes() {
+		func(i int, scope string) {
+			eg.Go(func() error {
+				cc, err := ci.loadScope(ctx, scope)
+				if err != nil {
+					return err
+				}
+				ccs[i] = cc
+				return nil
+			})
+		}(i, s.Scope)
+	}
+
+	if err := eg.Wait(); err != nil {
+		return nil, err
+	}
+
+	cms := make([]solver.CacheManager, 0, len(ccs))
+
+	for _, cc := range ccs {
+		keysStorage, resultStorage, err := v1.NewCacheKeyStorage(cc, w)
+		if err != nil {
+			return nil, err
+		}
+		cms = append(cms, solver.NewCacheManager(id, keysStorage, resultStorage))
+	}
+
+	return solver.NewCombinedCacheManager(cms, nil), nil
+}
+
+type ciProvider struct {
+	desc specs.Descriptor
+	ci   *importer
+}
+
+func (p *ciProvider) ReaderAt(ctx context.Context, desc specs.Descriptor) (content.ReaderAt, error) {
+	key := "buildkit-blob-" + version + "-" + desc.Digest.String()
+	ce, err := p.ci.cache.Load(ctx, key)
+	if err != nil {
+		return nil, err
+	}
+	if ce == nil {
+		return nil, errors.Errorf("blob not found")
+	}
+	rac := ce.Download(context.TODO())
+	return &readerAt{ReaderAtCloser: rac, desc: desc}, nil
+}
+
+type readerAt struct {
+	actionscache.ReaderAtCloser
+	desc specs.Descriptor
+}
+
+func (r *readerAt) Size() int64 {
+	return r.desc.Size
+}
+
+func oneOffProgress(ctx context.Context, id string) func(err error) error {
+	pw, _, _ := progress.NewFromContext(ctx)
+	now := time.Now()
+	st := progress.Status{
+		Started: &now,
+	}
+	pw.Write(id, st)
+	return func(err error) error {
+		now := time.Now()
+		st.Completed = &now
+		pw.Write(id, st)
+		pw.Close()
+		return err
+	}
+}

cache/remotecache/v1/spec.go

@@ -14,8 +14,16 @@ type CacheConfig struct {
 }
 
 type CacheLayer struct {
-	Blob        digest.Digest `json:"blob,omitempty"`
-	ParentIndex int           `json:"parent,omitempty"`
+	Blob        digest.Digest     `json:"blob,omitempty"`
+	ParentIndex int               `json:"parent,omitempty"`
+	Annotations *LayerAnnotations `json:"annotations,omitempty"`
+}
+
+type LayerAnnotations struct {
+	MediaType string        `json:"mediaType,omitempty"`
+	DiffID    digest.Digest `json:"diffID,omitempty"`
+	Size      int64         `json:"size,omitempty"`
+	CreatedAt time.Time     `json:"createdAt,omitempty"`
 }
 
 type CacheRecord struct {

cmd/buildkitd/main.go

@@ -27,6 +27,7 @@ import (
 	"github.com/gofrs/flock"
 	grpc_middleware "github.com/grpc-ecosystem/go-grpc-middleware"
 	"github.com/moby/buildkit/cache/remotecache"
+	"github.com/moby/buildkit/cache/remotecache/gha"
 	inlineremotecache "github.com/moby/buildkit/cache/remotecache/inline"
 	localremotecache "github.com/moby/buildkit/cache/remotecache/local"
 	registryremotecache "github.com/moby/buildkit/cache/remotecache/registry"
@@ -657,10 +658,12 @@ func newController(c *cli.Context, cfg *config.Config, md *toml.MetaData) (*cont
 		"registry": registryremotecache.ResolveCacheExporterFunc(sessionManager, resolverFn),
 		"local":    localremotecache.ResolveCacheExporterFunc(sessionManager),
 		"inline":   inlineremotecache.ResolveCacheExporterFunc(),
+		"gha":      gha.ResolveCacheExporterFunc(),
 	}
 	remoteCacheImporterFuncs := map[string]remotecache.ResolveCacheImporterFunc{
 		"registry": registryremotecache.ResolveCacheImporterFunc(sessionManager, w.ContentStore(), resolverFn),
 		"local":    localremotecache.ResolveCacheImporterFunc(sessionManager),
+		"gha":      gha.ResolveCacheImporterFunc(),
 	}
 
 	return control.NewController(control.Opt{