Do not obscure error message

Signed-off-by: Ralf Pannemans <ralf.pannemans@sap.com>

platform/resolve_analyze_inputs_test.go

@@ -111,7 +111,7 @@ func testResolveAnalyzeInputs(platformAPI string) func(t *testing.T, when spec.G
 								inputs.StackPath = "not-exist-stack.toml"
 								err := platform.ResolveInputs(platform.Analyze, inputs, logger)
 								h.AssertNotNil(t, err)
-								expected := "-run-image is required when there is no stack metadata available"
+								expected := "missing run image metadata (-run-image)"
 								h.AssertStringContains(t, err.Error(), expected)
 							})
 						})

platform/resolve_create_inputs_test.go

@@ -110,7 +110,7 @@ func testResolveCreateInputs(platformAPI string) func(t *testing.T, when spec.G,
 								inputs.StackPath = "not-exist-stack.toml"
 								err := platform.ResolveInputs(platform.Create, inputs, logger)
 								h.AssertNotNil(t, err)
-								expected := "-run-image is required when there is no stack metadata available"
+								expected := "missing run image metadata (-run-image)"
 								h.AssertStringContains(t, err.Error(), expected)
 							})
 						})

platform/resolve_inputs.go

@@ -11,13 +11,12 @@ import (
 )
 
 var (
-	ErrOutputImageRequired           = "image argument is required"
-	ErrRunImageRequiredWhenNoStackMD = "-run-image is required when there is no stack metadata available"
-	ErrRunImageRequiredWhenNoRunMD   = "-run-image is required when there is no run metadata available"
-	ErrSupplyOnlyOneRunImage         = "supply only one of -run-image or (deprecated) -image"
-	ErrRunImageUnsupported           = "-run-image is unsupported"
-	ErrImageUnsupported              = "-image is unsupported"
-	MsgIgnoringLaunchCache           = "Ignoring -launch-cache, only intended for use with -daemon"
+	ErrOutputImageRequired         = "image argument is required"
+	ErrRunImageRequiredWhenNoRunMD = "-run-image is required when there is no run metadata available"
+	ErrSupplyOnlyOneRunImage       = "supply only one of -run-image or (deprecated) -image"
+	ErrRunImageUnsupported         = "-run-image is unsupported"
+	ErrImageUnsupported            = "-image is unsupported"
+	MsgIgnoringLaunchCache         = "Ignoring -launch-cache, only intended for use with -daemon"
 )
 
 func ResolveInputs(phase LifecyclePhase, i *LifecycleInputs, logger log.Logger) error {
@@ -178,7 +177,7 @@ func fillRunImageFromStackTOMLIfNeeded(i *LifecycleInputs, logger log.Logger) er
 	}
 	i.RunImageRef, err = BestRunImageMirrorFor(targetRegistry, stackMD.RunImage, i.AccessChecker())
 	if err != nil {
-		return errors.New(ErrRunImageRequiredWhenNoStackMD)
+		return err
 	}
 	return nil
 }

platform/run_image.go

@@ -25,7 +25,7 @@ const (
 func BestRunImageMirrorFor(targetRegistry string, runImageMD files.RunImageForExport, checkReadAccess CheckReadAccess) (string, error) {
 	var runImageMirrors []string
 	if runImageMD.Image == "" {
-		return "", errors.New("missing run image metadata")
+		return "", errors.New("missing run image metadata (-run-image)")
 	}
 	runImageMirrors = append(runImageMirrors, runImageMD.Image)
 	runImageMirrors = append(runImageMirrors, runImageMD.Mirrors...)

platform/run_image_test.go

@@ -235,5 +235,18 @@ func testRunImage(t *testing.T, when spec.G, it spec.S) {
 				h.AssertEq(t, name, "gcr.io/myorg/myrepo")
 			})
 		})
+
+		when("there is no read access", func() {
+			it("fails", func() {
+				noReadAccess := func(_ string, _ authn.Keychain) (bool, error) {
+					return false, nil
+				}
+
+				_, err := platform.BestRunImageMirrorFor("gcr.io", stackMD.RunImage, noReadAccess)
+				h.AssertNotNil(t, err)
+				expected := "failed to find accessible run image"
+				h.AssertStringContains(t, err.Error(), expected)
+			})
+		})
 	})
 }