Add support for registries with self-signed certs

* add TLS transport option to ggcr client
* add global --ca-cert-path flag to irel
* add global --skip-tls-verify flag to irel

Note: the test certificate expires in over 2000 years, which should be long
enough.

pkg/irel/copy.go

@@ -18,10 +18,10 @@ package irel
 
 import (
 	"fmt"
+	"log"
+
 	"github.com/pivotal/image-relocation/pkg/image"
-	"github.com/pivotal/image-relocation/pkg/registry/ggcr"
 	"github.com/spf13/cobra"
-	"log"
 )
 
 func init() { Root.AddCommand(newCmdCopy()) }
@@ -47,7 +47,7 @@ func copy(cmd *cobra.Command, args []string) {
 		log.Fatalf("invalid reference %q: %v", dstStr, err)
 	}
 
-	regClient := ggcr.NewRegistryClient()
+	regClient := mustGetRegistryClient()
 	dig, _, err := regClient.Copy(src, dst)
 	if err != nil {
 		log.Fatalf("copy failed: %v", err)

pkg/irel/digest.go

@@ -18,10 +18,10 @@ package irel
 
 import (
 	"fmt"
+	"log"
+
 	"github.com/pivotal/image-relocation/pkg/image"
-	"github.com/pivotal/image-relocation/pkg/registry/ggcr"
 	"github.com/spf13/cobra"
-	"log"
 )
 
 func init() { Root.AddCommand(newCmdDigest()) }
@@ -43,7 +43,7 @@ func digest(cmd *cobra.Command, args []string) {
 		log.Fatalf("invalid reference %q: %v", refStr, err)
 	}
 
-	regClient := ggcr.NewRegistryClient()
+	regClient := mustGetRegistryClient()
 	dig, err := regClient.Digest(ref)
 	if err != nil {
 		log.Fatalf("digest failed: %v", err)

pkg/irel/layout_add.go

@@ -21,7 +21,6 @@ import (
 	"log"
 
 	"github.com/pivotal/image-relocation/pkg/image"
-	"github.com/pivotal/image-relocation/pkg/registry/ggcr"
 	"github.com/spf13/cobra"
 )
 
@@ -41,7 +40,7 @@ func layoutAdd(cmd *cobra.Command, args []string) {
 		log.Fatalf("invalid reference %q: %v", refStr, err)
 	}
 
-	regClient := ggcr.NewRegistryClient()
+	regClient := mustGetRegistryClient()
 	layout, err := regClient.ReadLayout(layoutPath)
 	if err != nil {
 		layout, err = regClient.NewLayout(layoutPath)

pkg/irel/layout_find.go

@@ -18,18 +18,18 @@ package irel
 
 import (
 	"fmt"
+	"log"
+
 	"github.com/pivotal/image-relocation/pkg/image"
-	"github.com/pivotal/image-relocation/pkg/registry/ggcr"
 	"github.com/spf13/cobra"
-	"log"
 )
 
 func newCmdLayoutFind() *cobra.Command {
 	return &cobra.Command{
-		Use:     "find LAYOUT_PATH REF",
-		Short:   "find an image in an OCI image layout",
-		Args:    cobra.ExactArgs(2),
-		Run:     layoutFind,
+		Use:   "find LAYOUT_PATH REF",
+		Short: "find an image in an OCI image layout",
+		Args:  cobra.ExactArgs(2),
+		Run:   layoutFind,
 	}
 }
 
@@ -40,7 +40,7 @@ func layoutFind(cmd *cobra.Command, args []string) {
 		log.Fatalf("invalid reference %q: %v", refStr, err)
 	}
 
-	regClient := ggcr.NewRegistryClient()
+	regClient := mustGetRegistryClient()
 	layout, err := regClient.ReadLayout(layoutPath)
 	if err != nil {
 		log.Fatalf("failed to create OCI image layout: %v", err)

pkg/irel/layout_push.go

@@ -18,18 +18,18 @@ package irel
 
 import (
 	"fmt"
+	"log"
+
 	"github.com/pivotal/image-relocation/pkg/image"
-	"github.com/pivotal/image-relocation/pkg/registry/ggcr"
 	"github.com/spf13/cobra"
-	"log"
 )
 
 func newCmdLayoutPush() *cobra.Command {
 	return &cobra.Command{
-		Use:     "push LAYOUT_PATH CONTENT_DIGEST REF",
-		Short:   "copy an image with a given content digest from an OCI image layout to a remote repository",
-		Args:    cobra.ExactArgs(3),
-		Run:     layoutPush,
+		Use:   "push LAYOUT_PATH CONTENT_DIGEST REF",
+		Short: "copy an image with a given content digest from an OCI image layout to a remote repository",
+		Args:  cobra.ExactArgs(3),
+		Run:   layoutPush,
 	}
 }
 
@@ -45,7 +45,7 @@ func layoutPush(cmd *cobra.Command, args []string) {
 		log.Fatalf("invalid digest %q: %v", digStr, err)
 	}
 
-	regClient := ggcr.NewRegistryClient()
+	regClient := mustGetRegistryClient()
 	layout, err := regClient.ReadLayout(layoutPath)
 	if err != nil {
 		log.Fatalf("failed to access OCI image layout: %v", err)

pkg/irel/root.go

@@ -16,12 +16,39 @@
 
 package irel
 
-import "github.com/spf13/cobra"
+import (
+	"log"
 
-var Root = &cobra.Command{
-	Use:               "irel",
-	Short:             "irel is a tool for relocating container images",
-	Run:               func(cmd *cobra.Command, _ []string) { cmd.Usage() },
-	DisableAutoGenTag: true,
+	"github.com/pivotal/image-relocation/pkg/registry"
+	"github.com/pivotal/image-relocation/pkg/registry/ggcr"
+	"github.com/pivotal/image-relocation/pkg/transport"
+
+	"github.com/spf13/cobra"
+)
+
+var (
+	caCertPaths   []string
+	skipTLSVerify bool
+
+	Root = &cobra.Command{
+		Use:               "irel",
+		Short:             "irel is a tool for relocating container images",
+		Run:               func(cmd *cobra.Command, _ []string) { cmd.Usage() },
+		DisableAutoGenTag: true,
+	}
+)
+
+func init() {
+	Root.PersistentFlags().StringSliceVarP(&caCertPaths, "ca-cert-path", "", nil, "Path to CA certificate for verifying registry TLS certificates (can be repeated for multiple certificates)")
+	Root.PersistentFlags().BoolVarP(&skipTLSVerify, "skip-tls-verify", "", false, "Skip TLS certificate verification for registries")
+}
+
+func mustGetRegistryClient() registry.Client {
+	tport, err := transport.NewHttpTransport(caCertPaths, skipTLSVerify)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	return ggcr.NewRegistryClient(ggcr.WithTransport(tport))
 }
 

pkg/registry/ggcr/client.go

@@ -18,6 +18,7 @@ package ggcr
 
 import (
 	"fmt"
+	"net/http"
 	"os"
 
 	v1 "github.com/google/go-containerregistry/pkg/v1"
@@ -43,28 +44,49 @@ type RegistryClient interface {
 	NewImageFromIndex(img v1.ImageIndex) registry.Image
 }
 
-type manifestWriter func(i v1.Image, n image.Name) error
-type indexWriter func(i v1.ImageIndex, n image.Name) error
+type manifestWriter func(v1.Image, image.Name) error
+type indexWriter func(v1.ImageIndex, image.Name) error
 
 type client struct {
-	readRemoteImage  func(n image.Name) (registry.Image, error)
+	readRemoteImage  func(image.Name) (registry.Image, error)
 	writeRemoteImage manifestWriter
 	writeRemoteIndex indexWriter
 }
 
 var (
 	// Ensure client conforms to the relevant interfaces.
-	_ RegistryClient = &client{}
+	_ RegistryClient  = &client{}
 	_ registry.Client = &client{}
 )
 
+// Option represents a functional option for NewRegistryClient.
+type Option func(*client)
+
+// WithTransport overrides the default transport used for remote operations, default is http.DefaultTransport.
+func WithTransport(transport http.RoundTripper) Option {
+	return func(c *client) {
+		writeRemoteImageFunc := writeRemoteImage(transport)
+		writeRemoteIndexFunc := writeRemoteIndex(transport)
+
+		c.readRemoteImage = readRemoteImage(writeRemoteImageFunc, writeRemoteIndexFunc, transport)
+		c.writeRemoteImage = writeRemoteImageFunc
+		c.writeRemoteIndex = writeRemoteIndexFunc
+	}
+}
+
 // NewRegistryClient returns a new Client.
-func NewRegistryClient() *client {
-	return &client{
-		readRemoteImage:  readRemoteImage(writeRemoteImage, writeRemoteIndex),
-		writeRemoteImage: writeRemoteImage,
-		writeRemoteIndex: writeRemoteIndex,
+func NewRegistryClient(options ...Option) *client {
+	client := &client{}
+
+	// default transport
+	WithTransport(http.DefaultTransport)(client)
+
+	// apply functional options
+	for _, opt := range options {
+		opt(client)
 	}
+
+	return client
 }
 
 func (r *client) Digest(n image.Name) (image.Digest, error) {

pkg/registry/ggcr/remote.go

@@ -18,9 +18,10 @@ package ggcr
 
 import (
 	"errors"
+	"net/http"
+
 	"github.com/google/go-containerregistry/pkg/v1/types"
 	"github.com/pivotal/image-relocation/pkg/registry"
-	"net/http"
 
 	"github.com/google/go-containerregistry/pkg/authn"
 	"github.com/google/go-containerregistry/pkg/name"
@@ -30,15 +31,14 @@ import (
 )
 
 var (
-	repoImageFunc      = remote.Image
 	resolveFunc        = authn.DefaultKeychain.Resolve
 	repoGetFunc        = remote.Get
 	repoWriteFunc      = remote.Write
 	repoIndexWriteFunc = remote.WriteIndex
 )
 
-func readRemoteImage(mfstWriter manifestWriter, idxWriter indexWriter) func(n image.Name) (registry.Image, error) {
-	return func(n image.Name) (i registry.Image, e error) {
+func readRemoteImage(mfstWriter manifestWriter, idxWriter indexWriter, transport http.RoundTripper) func(image.Name) (registry.Image, error) {
+	return func(n image.Name) (registry.Image, error) {
 		auth, err := resolve(n)
 		if err != nil {
 			return nil, err
@@ -56,7 +56,7 @@ func readRemoteImage(mfstWriter manifestWriter, idxWriter indexWriter) func(n im
 			return nil, err
 		}
 
-		desc, err := repoGetFunc(ref, remote.WithAuth(auth))
+		desc, err := repoGetFunc(ref, remote.WithAuth(auth), remote.WithTransport(transport))
 		if err != nil {
 			return nil, err
 		}
@@ -80,32 +80,36 @@ func readRemoteImage(mfstWriter manifestWriter, idxWriter indexWriter) func(n im
 	}
 }
 
-func writeRemoteImage(i v1.Image, n image.Name) error {
-	auth, err := resolve(n)
-	if err != nil {
-		return err
-	}
+func writeRemoteImage(transport http.RoundTripper) func(v1.Image, image.Name) error {
+	return func(i v1.Image, n image.Name) error {
+		auth, err := resolve(n)
+		if err != nil {
+			return err
+		}
 
-	ref, err := getWriteReference(n)
-	if err != nil {
-		return err
-	}
+		ref, err := getWriteReference(n)
+		if err != nil {
+			return err
+		}
 
-	return repoWriteFunc(ref, i, remote.WithAuth(auth), remote.WithTransport(http.DefaultTransport))
+		return repoWriteFunc(ref, i, remote.WithAuth(auth), remote.WithTransport(transport))
+	}
 }
 
-func writeRemoteIndex(i v1.ImageIndex, n image.Name) error {
-	auth, err := resolve(n)
-	if err != nil {
-		return err
-	}
+func writeRemoteIndex(transport http.RoundTripper) func(v1.ImageIndex, image.Name) error {
+	return func(i v1.ImageIndex, n image.Name) error {
+		auth, err := resolve(n)
+		if err != nil {
+			return err
+		}
 
-	ref, err := getWriteReference(n)
-	if err != nil {
-		return err
-	}
+		ref, err := getWriteReference(n)
+		if err != nil {
+			return err
+		}
 
-	return repoIndexWriteFunc(ref, i, remote.WithAuth(auth), remote.WithTransport(http.DefaultTransport))
+		return repoIndexWriteFunc(ref, i, remote.WithAuth(auth), remote.WithTransport(transport))
+	}
 }
 
 func resolve(n image.Name) (authn.Authenticator, error) {

pkg/registry/ggcr/remote_test.go

@@ -3,6 +3,7 @@ package ggcr
 import (
 	"errors"
 	"fmt"
+
 	"github.com/google/go-containerregistry/pkg/authn"
 	"github.com/google/go-containerregistry/pkg/name"
 	v1 "github.com/google/go-containerregistry/pkg/v1"
@@ -15,11 +16,11 @@ import (
 
 var _ = Describe("remote utilities", func() {
 	var (
-		imageName image.Name
-		mockImage *ggcrfakes.FakeImage
+		imageName  image.Name
+		mockImage  *ggcrfakes.FakeImage
 		testDigest string
-	testError error
-	err       error
+		testError  error
+		err        error
 	)
 
 	BeforeEach(func() {
@@ -40,7 +41,7 @@ var _ = Describe("remote utilities", func() {
 
 	Describe("readRemoteImage", func() {
 		JustBeforeEach(func() {
-			_, err = readRemoteImage(nil, nil)(imageName)
+			_, err = readRemoteImage(nil, nil, nil)(imageName)
 		})
 
 		BeforeEach(func() {
@@ -79,7 +80,7 @@ var _ = Describe("remote utilities", func() {
 
 	Describe("writeRemoteImage", func() {
 		JustBeforeEach(func() {
-			err = writeRemoteImage(mockImage, imageName)
+			err = writeRemoteImage(nil)(mockImage, imageName)
 		})
 
 		Context("when writing to the repository succeeds", func() {
@@ -141,7 +142,7 @@ var _ = Describe("remote utilities", func() {
 		})
 
 		JustBeforeEach(func() {
-			err = writeRemoteIndex(mockIndex, imageName)
+			err = writeRemoteIndex(nil)(mockIndex, imageName)
 		})
 
 		Context("when writing to the repository succeeds", func() {