github.com/docker/docker@v299999999.0.0-20200612211812-aaf470eca7b5+incompatible/builder/builder-next/adapters/localinlinecache/inlinecache.go (about)

     1  package localinlinecache
     2  
     3  import (
     4  	"context"
     5  	"encoding/json"
     6  	"time"
     7  
     8  	"github.com/containerd/containerd/content"
     9  	"github.com/containerd/containerd/images"
    10  	"github.com/containerd/containerd/remotes/docker"
    11  	distreference "github.com/docker/distribution/reference"
    12  	imagestore "github.com/docker/docker/image"
    13  	"github.com/docker/docker/reference"
    14  	"github.com/moby/buildkit/cache/remotecache"
    15  	registryremotecache "github.com/moby/buildkit/cache/remotecache/registry"
    16  	v1 "github.com/moby/buildkit/cache/remotecache/v1"
    17  	"github.com/moby/buildkit/session"
    18  	"github.com/moby/buildkit/solver"
    19  	"github.com/moby/buildkit/worker"
    20  	digest "github.com/opencontainers/go-digest"
    21  	specs "github.com/opencontainers/image-spec/specs-go/v1"
    22  	"github.com/pkg/errors"
    23  )
    24  
    25  // ResolveCacheImporterFunc returns a resolver function for local inline cache
    26  func ResolveCacheImporterFunc(sm *session.Manager, resolverFunc docker.RegistryHosts, cs content.Store, rs reference.Store, is imagestore.Store) remotecache.ResolveCacheImporterFunc {
    27  
    28  	upstream := registryremotecache.ResolveCacheImporterFunc(sm, cs, resolverFunc)
    29  
    30  	return func(ctx context.Context, attrs map[string]string) (remotecache.Importer, specs.Descriptor, error) {
    31  		if dt, err := tryImportLocal(rs, is, attrs["ref"]); err == nil {
    32  			return newLocalImporter(dt), specs.Descriptor{}, nil
    33  		}
    34  		return upstream(ctx, attrs)
    35  	}
    36  }
    37  
    38  func tryImportLocal(rs reference.Store, is imagestore.Store, refStr string) ([]byte, error) {
    39  	ref, err := distreference.ParseNormalizedNamed(refStr)
    40  	if err != nil {
    41  		return nil, err
    42  	}
    43  	dgst, err := rs.Get(ref)
    44  	if err != nil {
    45  		return nil, err
    46  	}
    47  	img, err := is.Get(imagestore.ID(dgst))
    48  	if err != nil {
    49  		return nil, err
    50  	}
    51  
    52  	return img.RawJSON(), nil
    53  }
    54  
    55  func newLocalImporter(dt []byte) remotecache.Importer {
    56  	return &localImporter{dt: dt}
    57  }
    58  
    59  type localImporter struct {
    60  	dt []byte
    61  }
    62  
    63  func (li *localImporter) Resolve(ctx context.Context, _ specs.Descriptor, id string, w worker.Worker) (solver.CacheManager, error) {
    64  	cc := v1.NewCacheChains()
    65  	if err := li.importInlineCache(ctx, li.dt, cc); err != nil {
    66  		return nil, err
    67  	}
    68  
    69  	keysStorage, resultStorage, err := v1.NewCacheKeyStorage(cc, w)
    70  	if err != nil {
    71  		return nil, err
    72  	}
    73  	return solver.NewCacheManager(id, keysStorage, resultStorage), nil
    74  }
    75  
    76  func (li *localImporter) importInlineCache(ctx context.Context, dt []byte, cc solver.CacheExporterTarget) error {
    77  	var img image
    78  
    79  	if err := json.Unmarshal(dt, &img); err != nil {
    80  		return err
    81  	}
    82  
    83  	if img.Cache == nil {
    84  		return nil
    85  	}
    86  
    87  	var config v1.CacheConfig
    88  	if err := json.Unmarshal(img.Cache, &config.Records); err != nil {
    89  		return err
    90  	}
    91  
    92  	createdDates, createdMsg, err := parseCreatedLayerInfo(img)
    93  	if err != nil {
    94  		return err
    95  	}
    96  
    97  	layers := v1.DescriptorProvider{}
    98  	for i, diffID := range img.Rootfs.DiffIDs {
    99  		dgst := digest.Digest(diffID.String())
   100  		desc := specs.Descriptor{
   101  			Digest:      dgst,
   102  			Size:        -1,
   103  			MediaType:   images.MediaTypeDockerSchema2Layer,
   104  			Annotations: map[string]string{},
   105  		}
   106  		if createdAt := createdDates[i]; createdAt != "" {
   107  			desc.Annotations["buildkit/createdat"] = createdAt
   108  		}
   109  		if createdBy := createdMsg[i]; createdBy != "" {
   110  			desc.Annotations["buildkit/description"] = createdBy
   111  		}
   112  		desc.Annotations["containerd.io/uncompressed"] = img.Rootfs.DiffIDs[i].String()
   113  		layers[dgst] = v1.DescriptorProviderPair{
   114  			Descriptor: desc,
   115  			Provider:   &emptyProvider{},
   116  		}
   117  		config.Layers = append(config.Layers, v1.CacheLayer{
   118  			Blob:        dgst,
   119  			ParentIndex: i - 1,
   120  		})
   121  	}
   122  
   123  	return v1.ParseConfig(config, layers, cc)
   124  }
   125  
   126  type image struct {
   127  	Rootfs struct {
   128  		DiffIDs []digest.Digest `json:"diff_ids"`
   129  	} `json:"rootfs"`
   130  	Cache   []byte `json:"moby.buildkit.cache.v0"`
   131  	History []struct {
   132  		Created    *time.Time `json:"created,omitempty"`
   133  		CreatedBy  string     `json:"created_by,omitempty"`
   134  		EmptyLayer bool       `json:"empty_layer,omitempty"`
   135  	} `json:"history,omitempty"`
   136  }
   137  
   138  func parseCreatedLayerInfo(img image) ([]string, []string, error) {
   139  	dates := make([]string, 0, len(img.Rootfs.DiffIDs))
   140  	createdBy := make([]string, 0, len(img.Rootfs.DiffIDs))
   141  	for _, h := range img.History {
   142  		if !h.EmptyLayer {
   143  			str := ""
   144  			if h.Created != nil {
   145  				dt, err := h.Created.MarshalText()
   146  				if err != nil {
   147  					return nil, nil, err
   148  				}
   149  				str = string(dt)
   150  			}
   151  			dates = append(dates, str)
   152  			createdBy = append(createdBy, h.CreatedBy)
   153  		}
   154  	}
   155  	return dates, createdBy, nil
   156  }
   157  
   158  type emptyProvider struct {
   159  }
   160  
   161  func (p *emptyProvider) ReaderAt(ctx context.Context, dec specs.Descriptor) (content.ReaderAt, error) {
   162  	return nil, errors.Errorf("ReaderAt not implemented for empty provider")
   163  }