fix: containerd localhost and 127.0.0.1 registry hosts (#334)

Signed-off-by: Chris Plock <[email protected]>

Author: chrisplo

pkg/image/containerd/daemon_provider.go

@@ -319,7 +319,7 @@ func (p *daemonImageProvider) fetchPlatformFromConfig(ctx context.Context, clien
 }
 
 func (p *daemonImageProvider) pullImageIfMissing(ctx context.Context, client *containerd.Client) (string, *platforms.Platform, error) {
-	p.imageStr = checkRegistryHostMissing(p.imageStr)
+	p.imageStr = ensureRegistryHostPrefix(p.imageStr)
 
 	// try to get the image first before pulling
 	resolvedImage, resolvedPlatform, err := p.resolveImage(ctx, client, p.imageStr)
@@ -511,13 +511,21 @@ func withMetadata(platform *platforms.Platform, ref string) (metadata []image.Ad
 	return metadata
 }
 
-// if image doesn't have host set, add docker hub by default
-func checkRegistryHostMissing(imageName string) string {
+// if imageName doesn't have an identifiable hostname prefix set,
+// add docker hub by default
+func ensureRegistryHostPrefix(imageName string) string {
 	parts := strings.Split(imageName, "/")
 	if len(parts) == 1 {
 		return fmt.Sprintf("docker.io/library/%s", imageName)
-	} else if len(parts) > 1 && !strings.Contains(parts[0], ".") {
-		return fmt.Sprintf("docker.io/%s", imageName)
 	}
-	return imageName
+	if isRegistryHostname(parts[0]) {
+		return imageName
+	}
+	return fmt.Sprintf("docker.io/%s", imageName)
+}
+
+// isRegistryHostname returns true if the string passed in can be interpreted
+// as a container registry hostname
+func isRegistryHostname(s string) bool {
+	return s == "localhost" || strings.Contains(s, ".") || strings.Contains(s, ":")
 }

pkg/image/containerd/daemon_provider_test.go

@@ -11,7 +11,7 @@ import (
 	"github.com/anchore/stereoscope/pkg/image"
 )
 
-func Test_checkRegistryHostMissing(t *testing.T) {
+func Test_ensureRegistryHostPrefix(t *testing.T) {
 	tests := []struct {
 		image string
 		want  string
@@ -32,6 +32,22 @@ func Test_checkRegistryHostMissing(t *testing.T) {
 			image: "registry.place.io/thing:version",
 			want:  "registry.place.io/thing:version",
 		},
+		{
+			image: "127.0.0.1/thing:version",
+			want:  "127.0.0.1/thing:version",
+		},
+		{
+			image: "127.0.0.1:1234/thing:version",
+			want:  "127.0.0.1:1234/thing:version",
+		},
+		{
+			image: "localhost/thing:version",
+			want:  "localhost/thing:version",
+		},
+		{
+			image: "localhost:1234/thing:version",
+			want:  "localhost:1234/thing:version",
+		},
 		{
 			image: "alpine@sha256:95cf004f559831017cdf4628aaf1bb30133677be8702a8c5f2994629f637a209",
 			want:  "docker.io/library/alpine@sha256:95cf004f559831017cdf4628aaf1bb30133677be8702a8c5f2994629f637a209",
@@ -43,7 +59,7 @@ func Test_checkRegistryHostMissing(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.image, func(t *testing.T) {
-			got := checkRegistryHostMissing(tt.image)
+			got := ensureRegistryHostPrefix(tt.image)
 			require.NotNil(t, got)
 			assert.Equal(t, tt.want, got)
 		})