Change upgrade path validation for 8.0 to only allow 7.17

pkg/controller/elasticsearch/validation/validations.go

@@ -272,11 +272,11 @@ func noDowngrades(current, proposed esv1.Elasticsearch) field.ErrorList {
 
 func validUpgradePath(current, proposed esv1.Elasticsearch) field.ErrorList {
 	var errs field.ErrorList
-	currentVer, err := version.Parse(current.Spec.Version)
-	if err != nil {
-		// this should not happen, since this is the already persisted version
-		errs = append(errs, field.Invalid(field.NewPath("spec").Child("version"), current.Spec.Version, parseStoredVersionErrMsg))
+	currentVer, ferr := currentVersion(current)
+	if ferr != nil {
+		errs = append(errs, ferr)
 	}
+
 	proposedVer, err := version.Parse(proposed.Spec.Version)
 	if err != nil {
 		errs = append(errs, field.Invalid(field.NewPath("spec").Child("version"), proposed.Spec.Version, parseVersionErrMsg))
@@ -298,6 +298,26 @@ func validUpgradePath(current, proposed esv1.Elasticsearch) field.ErrorList {
 	return errs
 }
 
+func currentVersion(current esv1.Elasticsearch) (version.Version, *field.Error) {
+	// we do not have a version in the status let's use the version in the current spec instead which will not reflect
+	// actually running Pods but which is still better than no validation.
+	if current.Status.Version == "" {
+		currentVer, err := version.Parse(current.Spec.Version)
+		if err != nil {
+			// this should not happen, since this is the version from the spec copied to the status by the operator
+			return version.Version{}, field.Invalid(field.NewPath("spec").Child("version"), current.Spec.Version, parseStoredVersionErrMsg)
+		}
+		return currentVer, nil
+	}
+	// if available use the status version which reflects the lowest version currently running in the cluster
+	currentVer, err := version.Parse(current.Status.Version)
+	if err != nil {
+		// this should not happen, since this is the already persisted version
+		return version.Version{}, field.Invalid(field.NewPath("status").Child("version"), current.Status.Version, parseStoredVersionErrMsg)
+	}
+	return currentVer, nil
+}
+
 func validMonitoring(es esv1.Elasticsearch) field.ErrorList {
 	return stackmon.Validate(&es, es.Spec.Version)
 }

pkg/controller/elasticsearch/version/supported_versions.go

@@ -36,8 +36,8 @@ func technicallySupportedVersions(v version.Version) *version.MinMaxVersion {
 		}
 	case 8:
 		return &version.MinMaxVersion{
-			// 7.4.0 is the lowest version that offers a direct upgrade path to 8.0
-			Min: version.MustParse("7.4.0"),
+			// 7.17.0 is the lowest version that offers a direct upgrade path to 8.0
+			Min: version.MinFor(7, 17, 0), // allow snapshot builds here for testing
 			Max: version.MustParse("8.99.99"),
 		}
 	default:

pkg/controller/elasticsearch/version/supported_versions_test.go

@@ -58,7 +58,7 @@ func TestSupportedVersions(t *testing.T) {
 				v: version.MustParse("8.0.0"),
 			},
 			supported: []version.Version{
-				version.MustParse("7.4.0"),
+				version.MustParse("7.17.0"),
 				version.MustParse("8.9.0"),
 			},
 			unsupported: []version.Version{