github.com/trgill/moby@v1.13.1/distribution/errors.go (about)

     1  package distribution
     2  
     3  import (
     4  	"net/url"
     5  	"strings"
     6  	"syscall"
     7  
     8  	"github.com/Sirupsen/logrus"
     9  	"github.com/docker/distribution"
    10  	"github.com/docker/distribution/registry/api/errcode"
    11  	"github.com/docker/distribution/registry/api/v2"
    12  	"github.com/docker/distribution/registry/client"
    13  	"github.com/docker/distribution/registry/client/auth"
    14  	"github.com/docker/docker/distribution/xfer"
    15  	"github.com/docker/docker/reference"
    16  	"github.com/pkg/errors"
    17  )
    18  
    19  // ErrNoSupport is an error type used for errors indicating that an operation
    20  // is not supported. It encapsulates a more specific error.
    21  type ErrNoSupport struct{ Err error }
    22  
    23  func (e ErrNoSupport) Error() string {
    24  	if e.Err == nil {
    25  		return "not supported"
    26  	}
    27  	return e.Err.Error()
    28  }
    29  
    30  // fallbackError wraps an error that can possibly allow fallback to a different
    31  // endpoint.
    32  type fallbackError struct {
    33  	// err is the error being wrapped.
    34  	err error
    35  	// confirmedV2 is set to true if it was confirmed that the registry
    36  	// supports the v2 protocol. This is used to limit fallbacks to the v1
    37  	// protocol.
    38  	confirmedV2 bool
    39  	// transportOK is set to true if we managed to speak HTTP with the
    40  	// registry. This confirms that we're using appropriate TLS settings
    41  	// (or lack of TLS).
    42  	transportOK bool
    43  }
    44  
    45  // Error renders the FallbackError as a string.
    46  func (f fallbackError) Error() string {
    47  	return f.Cause().Error()
    48  }
    49  
    50  func (f fallbackError) Cause() error {
    51  	return f.err
    52  }
    53  
    54  // shouldV2Fallback returns true if this error is a reason to fall back to v1.
    55  func shouldV2Fallback(err errcode.Error) bool {
    56  	switch err.Code {
    57  	case errcode.ErrorCodeUnauthorized, v2.ErrorCodeManifestUnknown, v2.ErrorCodeNameUnknown:
    58  		return true
    59  	}
    60  	return false
    61  }
    62  
    63  // TranslatePullError is used to convert an error from a registry pull
    64  // operation to an error representing the entire pull operation. Any error
    65  // information which is not used by the returned error gets output to
    66  // log at info level.
    67  func TranslatePullError(err error, ref reference.Named) error {
    68  	switch v := err.(type) {
    69  	case errcode.Errors:
    70  		if len(v) != 0 {
    71  			for _, extra := range v[1:] {
    72  				logrus.Infof("Ignoring extra error returned from registry: %v", extra)
    73  			}
    74  			return TranslatePullError(v[0], ref)
    75  		}
    76  	case errcode.Error:
    77  		var newErr error
    78  		switch v.Code {
    79  		case errcode.ErrorCodeDenied:
    80  			// ErrorCodeDenied is used when access to the repository was denied
    81  			newErr = errors.Errorf("repository %s not found: does not exist or no pull access", ref.Name())
    82  		case v2.ErrorCodeManifestUnknown:
    83  			newErr = errors.Errorf("manifest for %s not found", ref.String())
    84  		case v2.ErrorCodeNameUnknown:
    85  			newErr = errors.Errorf("repository %s not found", ref.Name())
    86  		}
    87  		if newErr != nil {
    88  			logrus.Infof("Translating %q to %q", err, newErr)
    89  			return newErr
    90  		}
    91  	case xfer.DoNotRetry:
    92  		return TranslatePullError(v.Err, ref)
    93  	}
    94  
    95  	return err
    96  }
    97  
    98  // continueOnError returns true if we should fallback to the next endpoint
    99  // as a result of this error.
   100  func continueOnError(err error) bool {
   101  	switch v := err.(type) {
   102  	case errcode.Errors:
   103  		if len(v) == 0 {
   104  			return true
   105  		}
   106  		return continueOnError(v[0])
   107  	case ErrNoSupport:
   108  		return continueOnError(v.Err)
   109  	case errcode.Error:
   110  		return shouldV2Fallback(v)
   111  	case *client.UnexpectedHTTPResponseError:
   112  		return true
   113  	case ImageConfigPullError:
   114  		return false
   115  	case error:
   116  		return !strings.Contains(err.Error(), strings.ToLower(syscall.ENOSPC.Error()))
   117  	}
   118  	// let's be nice and fallback if the error is a completely
   119  	// unexpected one.
   120  	// If new errors have to be handled in some way, please
   121  	// add them to the switch above.
   122  	return true
   123  }
   124  
   125  // retryOnError wraps the error in xfer.DoNotRetry if we should not retry the
   126  // operation after this error.
   127  func retryOnError(err error) error {
   128  	switch v := err.(type) {
   129  	case errcode.Errors:
   130  		if len(v) != 0 {
   131  			return retryOnError(v[0])
   132  		}
   133  	case errcode.Error:
   134  		switch v.Code {
   135  		case errcode.ErrorCodeUnauthorized, errcode.ErrorCodeUnsupported, errcode.ErrorCodeDenied, errcode.ErrorCodeTooManyRequests, v2.ErrorCodeNameUnknown:
   136  			return xfer.DoNotRetry{Err: err}
   137  		}
   138  	case *url.Error:
   139  		switch v.Err {
   140  		case auth.ErrNoBasicAuthCredentials, auth.ErrNoToken:
   141  			return xfer.DoNotRetry{Err: v.Err}
   142  		}
   143  		return retryOnError(v.Err)
   144  	case *client.UnexpectedHTTPResponseError:
   145  		return xfer.DoNotRetry{Err: err}
   146  	case error:
   147  		if err == distribution.ErrBlobUnknown {
   148  			return xfer.DoNotRetry{Err: err}
   149  		}
   150  		if strings.Contains(err.Error(), strings.ToLower(syscall.ENOSPC.Error())) {
   151  			return xfer.DoNotRetry{Err: err}
   152  		}
   153  	}
   154  	// let's be nice and fallback if the error is a completely
   155  	// unexpected one.
   156  	// If new errors have to be handled in some way, please
   157  	// add them to the switch above.
   158  	return err
   159  }