*: pluggable transports

Signed-off-by: Antonio Murdaca <runcom@redhat.com>
containers · Jan 20, 2017 · 20454d9 · 20454d9
1 parent b5c6de3
commit 20454d9
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Showing 13 changed files with 83 additions and 36 deletions.
diff --git a/copy/copy.go b/copy/copy.go
@@ -13,8 +13,9 @@ import (
 	"github.com/Sirupsen/logrus"
 	"github.com/containers/image/image"
 	"github.com/containers/image/manifest"
+	"github.com/containers/image/registeredtransports"
 	"github.com/containers/image/signature"
-	"github.com/containers/image/transports"
+	_ "github.com/containers/image/transports"
 	"github.com/containers/image/types"
 	"github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
@@ -106,14 +107,14 @@ func Image(policyContext *signature.PolicyContext, destRef, srcRef types.ImageRe
 
 	dest, err := destRef.NewImageDestination(options.DestinationCtx)
 	if err != nil {
-		return errors.Wrapf(err, "Error initializing destination %s", transports.ImageName(destRef))
+		return errors.Wrapf(err, "Error initializing destination %s", registeredtransports.ImageName(destRef))
 	}
 	defer dest.Close()
 	destSupportedManifestMIMETypes := dest.SupportedManifestMIMETypes()
 
 	rawSource, err := srcRef.NewImageSource(options.SourceCtx, destSupportedManifestMIMETypes)
 	if err != nil {
-		return errors.Wrapf(err, "Error initializing source %s", transports.ImageName(srcRef))
+		return errors.Wrapf(err, "Error initializing source %s", registeredtransports.ImageName(srcRef))
 	}
 	unparsedImage := image.UnparsedFromSource(rawSource)
 	defer func() {
@@ -128,13 +129,13 @@ func Image(policyContext *signature.PolicyContext, destRef, srcRef types.ImageRe
 	}
 	src, err := image.FromUnparsedImage(unparsedImage)
 	if err != nil {
-		return errors.Wrapf(err, "Error initializing image from source %s", transports.ImageName(srcRef))
+		return errors.Wrapf(err, "Error initializing image from source %s", registeredtransports.ImageName(srcRef))
 	}
 	unparsedImage = nil
 	defer src.Close()
 
 	if src.IsMultiImage() {
-		return errors.Errorf("can not copy %s: manifest contains multiple images", transports.ImageName(srcRef))
+		return errors.Errorf("can not copy %s: manifest contains multiple images", registeredtransports.ImageName(srcRef))
 	}
 
 	var sigs [][]byte
@@ -206,7 +207,7 @@ func Image(policyContext *signature.PolicyContext, destRef, srcRef types.ImageRe
 		}
 		dockerReference := dest.Reference().DockerReference()
 		if dockerReference == nil {
-			return errors.Errorf("Cannot determine canonical Docker reference for destination %s", transports.ImageName(dest.Reference()))
+			return errors.Errorf("Cannot determine canonical Docker reference for destination %s", registeredtransports.ImageName(dest.Reference()))
 		}
 
 		writeReport("Signing manifest\n")

diff --git a/directory/directory_transport.go b/directory/directory_transport.go
@@ -10,10 +10,15 @@ import (
 	"github.com/containers/image/directory/explicitfilepath"
 	"github.com/containers/image/docker/reference"
 	"github.com/containers/image/image"
+	"github.com/containers/image/registeredtransports"
 	"github.com/containers/image/types"
 	"github.com/opencontainers/go-digest"
 )
 
+func init() {
+	registeredtransports.Register(Transport)
+}
+
 // Transport is an ImageTransport for directory paths.
 var Transport = dirTransport{}
 

diff --git a/docker/docker_transport.go b/docker/docker_transport.go
@@ -6,10 +6,15 @@ import (
 
 	"github.com/containers/image/docker/policyconfiguration"
 	"github.com/containers/image/docker/reference"
+	"github.com/containers/image/registeredtransports"
 	"github.com/containers/image/types"
 	"github.com/pkg/errors"
 )
 
+func init() {
+	registeredtransports.Register(Transport)
+}
+
 // Transport is an ImageTransport for Docker registry-hosted images.
 var Transport = dockerTransport{}
 

diff --git a/oci/layout/oci_transport.go b/oci/layout/oci_transport.go
@@ -9,11 +9,16 @@ import (
 	"github.com/containers/image/directory/explicitfilepath"
 	"github.com/containers/image/docker/reference"
 	"github.com/containers/image/image"
+	"github.com/containers/image/registeredtransports"
 	"github.com/containers/image/types"
 	"github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
 )
 
+func init() {
+	registeredtransports.Register(Transport)
+}
+
 // Transport is an ImageTransport for OCI directories.
 var Transport = ociTransport{}
 

diff --git a/openshift/openshift_transport.go b/openshift/openshift_transport.go
@@ -8,10 +8,15 @@ import (
 	"github.com/containers/image/docker/policyconfiguration"
 	"github.com/containers/image/docker/reference"
 	genericImage "github.com/containers/image/image"
+	"github.com/containers/image/registeredtransports"
 	"github.com/containers/image/types"
 	"github.com/pkg/errors"
 )
 
+func init() {
+	registeredtransports.Register(Transport)
+}
+
 // Transport is an ImageTransport for OpenShift registry-hosted images.
 var Transport = openshiftTransport{}
 

diff --git a/registeredtransports/registeredtransports.go b/registeredtransports/registeredtransports.go
@@ -0,0 +1,34 @@
+package registeredtransports
+
+import (
+	"fmt"
+
+	"github.com/containers/image/types"
+)
+
+// KnownTransports is a registry of known ImageTransport instances.
+var KnownTransports map[string]types.ImageTransport
+
+func init() {
+	KnownTransports = make(map[string]types.ImageTransport)
+}
+
+// Register TODO(runcom)
+func Register(t types.ImageTransport) {
+	name := t.Name()
+	if _, ok := KnownTransports[name]; ok {
+		panic(fmt.Sprintf("Duplicate image transport name %s", name))
+	}
+	KnownTransports[name] = t
+}
+
+// ImageName converts a types.ImageReference into an URL-like image name, which MUST be such that
+// ParseImageName(ImageName(reference)) returns an equivalent reference.
+//
+// This is the generally recommended way to refer to images in the UI.
+//
+// NOTE: The returned string is not promised to be equal to the original input to ParseImageName;
+// e.g. default attribute values omitted by the user may be filled in in the return value, or vice versa.
+func ImageName(ref types.ImageReference) string {
+	return ref.Transport().Name() + ":" + ref.StringWithinTransport()
+}
diff --git a/signature/policy_config.go b/signature/policy_config.go
@@ -22,7 +22,7 @@ import (
 	"github.com/pkg/errors"
 
 	"github.com/containers/image/docker/reference"
-	"github.com/containers/image/transports"
+	"github.com/containers/image/registeredtransports"
 	"github.com/containers/image/types"
 )
 
@@ -123,7 +123,7 @@ func (m *policyTransportsMap) UnmarshalJSON(data []byte) error {
 	// So, use a temporary map of pointers-to-slices and convert.
 	tmpMap := map[string]*PolicyTransportScopes{}
 	if err := paranoidUnmarshalJSONObject(data, func(key string) interface{} {
-		transport, ok := transports.KnownTransports[key]
+		transport, ok := registeredtransports.KnownTransports[key]
 		if !ok {
 			return nil
 		}

diff --git a/signature/policy_eval_simple.go b/signature/policy_eval_simple.go
@@ -5,7 +5,7 @@ package signature
 import (
 	"fmt"
 
-	"github.com/containers/image/transports"
+	"github.com/containers/image/registeredtransports"
 	"github.com/containers/image/types"
 )
 
@@ -20,9 +20,9 @@ func (pr *prInsecureAcceptAnything) isRunningImageAllowed(image types.UnparsedIm
 }
 
 func (pr *prReject) isSignatureAuthorAccepted(image types.UnparsedImage, sig []byte) (signatureAcceptanceResult, *Signature, error) {
-	return sarRejected, nil, PolicyRequirementError(fmt.Sprintf("Any signatures for image %s are rejected by policy.", transports.ImageName(image.Reference())))
+	return sarRejected, nil, PolicyRequirementError(fmt.Sprintf("Any signatures for image %s are rejected by policy.", registeredtransports.ImageName(image.Reference())))
 }
 
 func (pr *prReject) isRunningImageAllowed(image types.UnparsedImage) (bool, error) {
-	return false, PolicyRequirementError(fmt.Sprintf("Running image %s is rejected by policy.", transports.ImageName(image.Reference())))
+	return false, PolicyRequirementError(fmt.Sprintf("Running image %s is rejected by policy.", registeredtransports.ImageName(image.Reference())))
 }
diff --git a/signature/policy_reference_match.go b/signature/policy_reference_match.go
@@ -6,7 +6,7 @@ import (
 	"fmt"
 
 	"github.com/containers/image/docker/reference"
-	"github.com/containers/image/transports"
+	"github.com/containers/image/registeredtransports"
 	"github.com/containers/image/types"
 )
 
@@ -15,7 +15,7 @@ func parseImageAndDockerReference(image types.UnparsedImage, s2 string) (referen
 	r1 := image.Reference().DockerReference()
 	if r1 == nil {
 		return nil, nil, PolicyRequirementError(fmt.Sprintf("Docker reference match attempted on image %s with no known Docker reference identity",
-			transports.ImageName(image.Reference())))
+			registeredtransports.ImageName(image.Reference())))
 	}
 	r2, err := reference.ParseNamed(s2)
 	if err != nil {

diff --git a/signature/signature_test.go b/signature/signature_test.go
@@ -5,6 +5,7 @@ import (
 	"io/ioutil"
 	"testing"
 
+	_ "github.com/containers/image/openshift"
 	"github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
 	"github.com/stretchr/testify/assert"

diff --git a/storage/storage_transport.go b/storage/storage_transport.go
@@ -9,12 +9,17 @@ import (
 
 	"github.com/Sirupsen/logrus"
 	"github.com/containers/image/docker/reference"
+	"github.com/containers/image/registeredtransports"
 	"github.com/containers/image/types"
 	"github.com/containers/storage/storage"
 	"github.com/opencontainers/go-digest"
 	ddigest "github.com/opencontainers/go-digest"
 )
 
+func init() {
+	registeredtransports.Register(Transport)
+}
+
 var (
 	// Transport is an ImageTransport that uses either a default
 	// storage.Store or one that's it's explicitly told to use.

diff --git a/transports/transports.go b/transports/transports.go
@@ -1,24 +1,20 @@
 package transports
 
 import (
-	"fmt"
 	"strings"
 
 	"github.com/containers/image/directory"
 	"github.com/containers/image/docker"
 	"github.com/containers/image/docker/daemon"
 	ociLayout "github.com/containers/image/oci/layout"
 	"github.com/containers/image/openshift"
+	"github.com/containers/image/registeredtransports"
 	"github.com/containers/image/storage"
 	"github.com/containers/image/types"
 	"github.com/pkg/errors"
 )
 
-// KnownTransports is a registry of known ImageTransport instances.
-var KnownTransports map[string]types.ImageTransport
-
 func init() {
-	KnownTransports = make(map[string]types.ImageTransport)
 	// NOTE: Make sure docs/policy.json.md is updated when adding or updating
 	// a transport.
 	for _, t := range []types.ImageTransport{
@@ -30,10 +26,10 @@ func init() {
 		storage.Transport,
 	} {
 		name := t.Name()
-		if _, ok := KnownTransports[name]; ok {
-			panic(fmt.Sprintf("Duplicate image transport name %s", name))
+		if _, ok := registeredtransports.KnownTransports[name]; ok {
+			continue
 		}
-		KnownTransports[name] = t
+		registeredtransports.Register(t)
 	}
 }
 
@@ -43,20 +39,9 @@ func ParseImageName(imgName string) (types.ImageReference, error) {
 	if len(parts) != 2 {
 		return nil, errors.Errorf(`Invalid image name "%s", expected colon-separated transport:reference`, imgName)
 	}
-	transport, ok := KnownTransports[parts[0]]
+	transport, ok := registeredtransports.KnownTransports[parts[0]]
 	if !ok {
 		return nil, errors.Errorf(`Invalid image name "%s", unknown transport "%s"`, imgName, parts[0])
 	}
 	return transport.ParseReference(parts[1])
 }
-
-// ImageName converts a types.ImageReference into an URL-like image name, which MUST be such that
-// ParseImageName(ImageName(reference)) returns an equivalent reference.
-//
-// This is the generally recommended way to refer to images in the UI.
-//
-// NOTE: The returned string is not promised to be equal to the original input to ParseImageName;
-// e.g. default attribute values omitted by the user may be filled in in the return value, or vice versa.
-func ImageName(ref types.ImageReference) string {
-	return ref.Transport().Name() + ":" + ref.StringWithinTransport()
-}
diff --git a/transports/transports_test.go b/transports/transports_test.go
@@ -3,13 +3,14 @@ package transports
 import (
 	"testing"
 
+	"github.com/containers/image/registeredtransports"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
 func TestKnownTransports(t *testing.T) {
-	assert.NotNil(t, KnownTransports) // Ensure that the initialization has actually been run
-	assert.True(t, len(KnownTransports) > 1)
+	assert.NotNil(t, registeredtransports.KnownTransports) // Ensure that the initialization has actually been run
+	assert.True(t, len(registeredtransports.KnownTransports) > 1)
 }
 
 func TestParseImageName(t *testing.T) {
@@ -40,7 +41,7 @@ func TestImageNameHandling(t *testing.T) {
 		fullInput := c.transport + ":" + c.input
 		ref, err := ParseImageName(fullInput)
 		require.NoError(t, err, fullInput)
-		s := ImageName(ref)
+		s := registeredtransports.ImageName(ref)
 		assert.Equal(t, c.transport+":"+c.roundtrip, s, fullInput)
 	}
 }