Add initial SemVer upgrade support

OLM will now use SemVer to determine next upgrade.
In this iteration we only support upgrade within the same major versions:
e.g 1.0.1 can be upgraded to 1.0.2 or 1.3.2, but not 2.0.0.

Signed-off-by: Mikalai Radchuk <mradchuk@redhat.com>

internal/resolution/variablesources/installed_package.go

@@ -5,13 +5,15 @@ import (
 	"fmt"
 	"sort"
 
+	mmsemver "github.com/Masterminds/semver/v3"
 	"github.com/operator-framework/deppy/pkg/deppy"
 	"github.com/operator-framework/deppy/pkg/deppy/input"
 
 	"github.com/operator-framework/operator-controller/internal/catalogmetadata"
 	catalogfilter "github.com/operator-framework/operator-controller/internal/catalogmetadata/filter"
 	catalogsort "github.com/operator-framework/operator-controller/internal/catalogmetadata/sort"
 	"github.com/operator-framework/operator-controller/internal/resolution/variables"
+	"github.com/operator-framework/operator-controller/pkg/features"
 )
 
 var _ input.VariableSource = &InstalledPackageVariableSource{}
@@ -59,10 +61,15 @@ func (r *InstalledPackageVariableSource) notFoundError() error {
 }
 
 func NewInstalledPackageVariableSource(catalogClient BundleProvider, bundleImage string) (*InstalledPackageVariableSource, error) {
+	successors := legacySemanticsSuccessors
+	if features.OperatorControllerFeatureGate.Enabled(features.ForceSemverUpgradeConstraints) {
+		successors = semverSuccessors
+	}
+
 	return &InstalledPackageVariableSource{
 		catalogClient: catalogClient,
 		bundleImage:   bundleImage,
-		successors:    legacySemanticsSuccessors,
+		successors:    successors,
 	}, nil
 }
 
@@ -83,3 +90,28 @@ func legacySemanticsSuccessors(allBundles []*catalogmetadata.Bundle, installedBu
 
 	return upgradeEdges, nil
 }
+
+// semverSuccessors returns successors based on Semver.
+// Successors will not include versions outside the major version of the
+// installed bundle as major version is intended to indicate breaking changes.
+func semverSuccessors(allBundles []*catalogmetadata.Bundle, installedBundle *catalogmetadata.Bundle) ([]*catalogmetadata.Bundle, error) {
+	currentVersion, err := installedBundle.Version()
+	if err != nil {
+		return nil, err
+	}
+
+	// Based on current version create a caret range comparison constraint
+	// to allow only major and patch version as successors and exclude current version.
+	constraintStr := fmt.Sprintf("^%s, != %s", currentVersion.String(), currentVersion.String())
+	wantedVersionRangeConstraint, err := mmsemver.NewConstraint(constraintStr)
+	if err != nil {
+		return nil, err
+	}
+
+	upgradeEdges := catalogfilter.Filter(allBundles, catalogfilter.InMastermindsSemverRange(wantedVersionRangeConstraint))
+	sort.SliceStable(upgradeEdges, func(i, j int) bool {
+		return catalogsort.ByVersion(upgradeEdges[i], upgradeEdges[j])
+	})
+
+	return upgradeEdges, nil
+}

internal/resolution/variablesources/installed_package_test.go

@@ -120,6 +120,27 @@ func TestInstalledPackageVariableSource(t *testing.T) {
 	const bundleImage = "registry.io/repo/test-package@v2.0.0"
 	fakeCatalogClient := testutil.NewFakeCatalogClient(bundleList)
 
+	t.Run("with ForceSemverUpgradeConstraints feature gate enabled", func(t *testing.T) {
+		defer featuregatetesting.SetFeatureGateDuringTest(t, features.OperatorControllerFeatureGate, features.ForceSemverUpgradeConstraints, true)()
+
+		ipvs, err := variablesources.NewInstalledPackageVariableSource(&fakeCatalogClient, bundleImage)
+		assert.NoError(t, err)
+
+		variables, err := ipvs.GetVariables(context.TODO())
+		assert.NoError(t, err)
+		assert.Len(t, variables, 1)
+		packageVariable, ok := variables[0].(*olmvariables.InstalledPackageVariable)
+		assert.True(t, ok)
+		assert.Equal(t, deppy.IdentifierFromString("installed package test-package"), packageVariable.Identifier())
+
+		// ensure bundles are in version order (high to low)
+		bundles := packageVariable.Bundles()
+		assert.Len(t, bundles, 3)
+		assert.Equal(t, "test-package.v2.2.0", packageVariable.Bundles()[0].Name)
+		assert.Equal(t, "test-package.v2.1.0", packageVariable.Bundles()[1].Name)
+		assert.Equal(t, "test-package.v2.0.0", packageVariable.Bundles()[2].Name)
+	})
+
 	t.Run("with ForceSemverUpgradeConstraints feature gate disabled", func(t *testing.T) {
 		defer featuregatetesting.SetFeatureGateDuringTest(t, features.OperatorControllerFeatureGate, features.ForceSemverUpgradeConstraints, false)()