github.com/tonistiigi/docker@v0.10.1-0.20240229224939-974013b0dc6a/distribution/utils/progress.go (about)

     1  package utils // import "github.com/docker/docker/distribution/utils"
     2  
     3  import (
     4  	"context"
     5  	"io"
     6  	"net"
     7  	"os"
     8  	"syscall"
     9  
    10  	"github.com/containerd/log"
    11  	"github.com/docker/docker/pkg/progress"
    12  	"github.com/docker/docker/pkg/streamformatter"
    13  )
    14  
    15  // WriteDistributionProgress is a helper for writing progress from chan to JSON
    16  // stream with an optional cancel function.
    17  func WriteDistributionProgress(cancelFunc func(), outStream io.Writer, progressChan <-chan progress.Progress) {
    18  	progressOutput := streamformatter.NewJSONProgressOutput(outStream, false)
    19  	operationCancelled := false
    20  
    21  	for prog := range progressChan {
    22  		if err := progressOutput.WriteProgress(prog); err != nil && !operationCancelled {
    23  			// don't log broken pipe errors as this is the normal case when a client aborts
    24  			if isBrokenPipe(err) {
    25  				log.G(context.TODO()).Info("Pull session cancelled")
    26  			} else {
    27  				log.G(context.TODO()).Errorf("error writing progress to client: %v", err)
    28  			}
    29  			cancelFunc()
    30  			operationCancelled = true
    31  			// Don't return, because we need to continue draining
    32  			// progressChan until it's closed to avoid a deadlock.
    33  		}
    34  	}
    35  }
    36  
    37  func isBrokenPipe(e error) bool {
    38  	if netErr, ok := e.(*net.OpError); ok {
    39  		e = netErr.Err
    40  		if sysErr, ok := netErr.Err.(*os.SyscallError); ok {
    41  			e = sysErr.Err
    42  		}
    43  	}
    44  	return e == syscall.EPIPE
    45  }