Recognize the new lookaside names for simple signing sigstore

Signed-off-by: Miloslav Trmač <mitr@redhat.com>

pkg/trust/registries.go

@@ -22,6 +22,8 @@ type registryConfiguration struct {
 
 // registryNamespace defines lookaside locations for a single namespace.
 type registryNamespace struct {
+	Lookaside        string `json:"lookaside"`         // For reading, and if LookasideStaging is not present, for writing.
+	LookasideStaging string `json:"lookaside-staging"` // For writing only.
 	SigStore         string `json:"sigstore"`          // For reading, and if SigStoreStaging is not present, for writing.
 	SigStoreStaging  string `json:"sigstore-staging"`  // For writing only.
 }

pkg/trust/testdata/quay.io.yaml

@@ -0,0 +1,3 @@
+docker:
+     quay.io/multi-signed:
+         lookaside: https://quay.example.com/sigstore

pkg/trust/trust.go

@@ -91,8 +91,12 @@ func getPolicyShowOutput(policyContentStruct policyContent, systemRegistriesDirP
 
 			registryNamespace := haveMatchRegistry(repo, registryConfigs)
 			if registryNamespace != nil {
+				if registryNamespace.Lookaside != "" {
+					tempTrustShowOutput.SignatureStore = registryNamespace.Lookaside
+				} else { // incl. registryNamespace.SigStore == ""
 					tempTrustShowOutput.SignatureStore = registryNamespace.SigStore
 				}
+			}
 			output = append(output, &tempTrustShowOutput)
 		}
 	}

pkg/trust/trust_test.go

@@ -66,7 +66,7 @@ func TestPolicyDescription(t *testing.T) {
 					Name:           "quay.io/multi-signed",
 					RepoName:       "quay.io/multi-signed",
 					Type:           "signed",
-					SignatureStore: "",
+					SignatureStore: "https://quay.example.com/sigstore",
 					GPGId:          "1, 2, 3",
 				},
 				{