 39158629f7
			
		
	
	39158629f7
	
	
	
		
			
			`rc.r.Read()` may return a negative `int` on an error when the reader is set to a custom content store implementation Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
		
			
				
	
	
		
			133 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			133 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| /*
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|    Copyright The containerd Authors.
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| 
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|    Licensed under the Apache License, Version 2.0 (the "License");
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|    you may not use this file except in compliance with the License.
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|    You may obtain a copy of the License at
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| 
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|        http://www.apache.org/licenses/LICENSE-2.0
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| 
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|    Unless required by applicable law or agreed to in writing, software
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|    distributed under the License is distributed on an "AS IS" BASIS,
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|    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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|    See the License for the specific language governing permissions and
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|    limitations under the License.
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| */
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| 
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| package apply
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| 
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| import (
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| 	"context"
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| 	"fmt"
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| 	"io"
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| 	"time"
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| 
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| 	"github.com/containerd/containerd/content"
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| 	"github.com/containerd/containerd/diff"
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| 	"github.com/containerd/containerd/log"
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| 	"github.com/containerd/containerd/mount"
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| 	digest "github.com/opencontainers/go-digest"
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| 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
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| 	"github.com/sirupsen/logrus"
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| )
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| 
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| // NewFileSystemApplier returns an applier which simply mounts
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| // and applies diff onto the mounted filesystem.
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| func NewFileSystemApplier(cs content.Provider) diff.Applier {
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| 	return &fsApplier{
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| 		store: cs,
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| 	}
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| }
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| 
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| type fsApplier struct {
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| 	store content.Provider
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| }
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| 
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| var emptyDesc = ocispec.Descriptor{}
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| 
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| // Apply applies the content associated with the provided digests onto the
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| // provided mounts. Archive content will be extracted and decompressed if
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| // necessary.
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| func (s *fsApplier) Apply(ctx context.Context, desc ocispec.Descriptor, mounts []mount.Mount, opts ...diff.ApplyOpt) (d ocispec.Descriptor, err error) {
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| 	t1 := time.Now()
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| 	defer func() {
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| 		if err == nil {
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| 			log.G(ctx).WithFields(logrus.Fields{
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| 				"d":      time.Since(t1),
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| 				"digest": desc.Digest,
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| 				"size":   desc.Size,
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| 				"media":  desc.MediaType,
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| 			}).Debugf("diff applied")
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| 		}
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| 	}()
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| 
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| 	var config diff.ApplyConfig
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| 	for _, o := range opts {
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| 		if err := o(ctx, desc, &config); err != nil {
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| 			return emptyDesc, fmt.Errorf("failed to apply config opt: %w", err)
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| 		}
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| 	}
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| 
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| 	ra, err := s.store.ReaderAt(ctx, desc)
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| 	if err != nil {
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| 		return emptyDesc, fmt.Errorf("failed to get reader from content store: %w", err)
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| 	}
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| 	defer ra.Close()
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| 
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| 	var processors []diff.StreamProcessor
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| 	processor := diff.NewProcessorChain(desc.MediaType, content.NewReader(ra))
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| 	processors = append(processors, processor)
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| 	for {
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| 		if processor, err = diff.GetProcessor(ctx, processor, config.ProcessorPayloads); err != nil {
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| 			return emptyDesc, fmt.Errorf("failed to get stream processor for %s: %w", desc.MediaType, err)
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| 		}
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| 		processors = append(processors, processor)
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| 		if processor.MediaType() == ocispec.MediaTypeImageLayer {
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| 			break
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| 		}
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| 	}
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| 	defer processor.Close()
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| 
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| 	digester := digest.Canonical.Digester()
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| 	rc := &readCounter{
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| 		r: io.TeeReader(processor, digester.Hash()),
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| 	}
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| 
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| 	if err := apply(ctx, mounts, rc); err != nil {
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| 		return emptyDesc, err
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| 	}
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| 
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| 	// Read any trailing data
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| 	if _, err := io.Copy(io.Discard, rc); err != nil {
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| 		return emptyDesc, err
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| 	}
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| 
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| 	for _, p := range processors {
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| 		if ep, ok := p.(interface {
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| 			Err() error
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| 		}); ok {
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| 			if err := ep.Err(); err != nil {
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| 				return emptyDesc, err
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| 			}
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| 		}
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| 	}
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| 	return ocispec.Descriptor{
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| 		MediaType: ocispec.MediaTypeImageLayer,
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| 		Size:      rc.c,
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| 		Digest:    digester.Digest(),
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| 	}, nil
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| }
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| 
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| type readCounter struct {
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| 	r io.Reader
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| 	c int64
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| }
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| 
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| func (rc *readCounter) Read(p []byte) (n int, err error) {
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| 	n, err = rc.r.Read(p)
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| 	if n > 0 {
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| 		rc.c += int64(n)
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| 	}
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| 	return
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| }
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