don't attempt to discover keys for file path repos (#1326)

Signed-off-by: Jason Hall <jason@chainguard.dev>

pkg/apk/apk/implementation.go

@@ -824,7 +824,16 @@ func DiscoverKeys(ctx context.Context, client *http.Client, auth auth.Authentica
 	ctx, span := otel.Tracer("go-apk").Start(ctx, "DiscoverKeys")
 	defer span.End()
 
-	discoveryRequest, err := http.NewRequestWithContext(ctx, http.MethodGet, fmt.Sprintf("%s/%s", strings.TrimSuffix(repository, "/"), "apk-configuration"), nil)
+	if !strings.HasPrefix(repository, "https://") && !strings.HasPrefix(repository, "http://") {
+		// Ignore non-remote repositories.
+		return nil, nil
+	}
+	asURL, err := url.Parse(strings.TrimSuffix(repository, "/") + "/apk-configuration")
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse repository URL: %w", err)
+	}
+
+	discoveryRequest, err := http.NewRequestWithContext(ctx, http.MethodGet, asURL.String(), nil)
 	if err != nil {
 		return nil, err
 	}

pkg/apk/apk/implementation_test.go

@@ -111,11 +111,7 @@ func TestInitDB_ChainguardDiscovery(t *testing.T) {
 	apk, err := New(WithFS(src), WithIgnoreMknodErrors(ignoreMknodErrors))
 	require.NoError(t, err)
 
-	// This is a staging group that was set up to host public images published
-	// by https://github.com/chainguard-dev/terraform-provider-apko presubmit.
-	// TODO(mattmoor): Once we push this out to production, we should switch to
-	// using apk.cgr.dev/chainguard or apk.cgr.dev/extra-packages.
-	err = apk.InitDB(context.Background(), "https://apk.chainreg.biz/tf-apko.pub")
+	err = apk.InitDB(context.Background(), "https://apk.cgr.dev/chainguard")
 	require.NoError(t, err)
 	// check all of the contents
 	for _, d := range initDirectories {