add crd uniqueness variable source (#98)

Signed-off-by: perdasilva <[email protected]>

Author: perdasilva

internal/resolution/variable_sources/bundles_and_dependencies/bundles_and_dependencies.go

@@ -95,7 +95,7 @@ func (b *BundlesAndDepsVariableSource) GetVariables(ctx context.Context, entityS
 		// get bundle dependencies
 		dependencyEntityBundles, err := b.getEntityDependencies(ctx, head, entitySource)
 		if err != nil {
-			return nil, fmt.Errorf("could not determine dependencies for entity with id '%s': %s", head.ID, err)
+			return nil, fmt.Errorf("could not determine dependencies for entity with id '%s': %w", head.ID, err)
 		}
 
 		// add bundle dependencies to queue for processing

internal/resolution/variable_sources/crd_constraints/crd_constraints.go

@@ -0,0 +1,117 @@
+package crd_constraints
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/operator-framework/deppy/pkg/deppy"
+	"github.com/operator-framework/deppy/pkg/deppy/constraint"
+	"github.com/operator-framework/deppy/pkg/deppy/input"
+
+	"github.com/operator-framework/operator-controller/internal/resolution/variable_sources/bundles_and_dependencies"
+	olmentity "github.com/operator-framework/operator-controller/internal/resolution/variable_sources/entity"
+)
+
+type BundleUniquenessVariable struct {
+	*input.SimpleVariable
+}
+
+// NewBundleUniquenessVariable creates a new variable that instructs the resolver to choose at most a single bundle
+// from the input 'atMostID'. Examples:
+// 1. restrict the solution to at most a single bundle per package
+// 2. restrict the solution to at most a single bundler per provided gvk
+// this guarantees that no two operators provide the same gvk and no two version of the same operator are running at the same time
+func NewBundleUniquenessVariable(id deppy.Identifier, atMostIDs ...deppy.Identifier) *BundleUniquenessVariable {
+	return &BundleUniquenessVariable{
+		SimpleVariable: input.NewSimpleVariable(id, constraint.AtMost(1, atMostIDs...)),
+	}
+}
+
+var _ input.VariableSource = &CRDUniquenessConstraintsVariableSource{}
+
+// CRDUniquenessConstraintsVariableSource produces variables that constraint the solution to
+// 1. at most 1 bundle per package
+// 2. at most 1 bundle per gvk (provided by the bundle)
+// these variables guarantee that no two operators provide the same gvk and no two version of
+// the same operator are running at the same time.
+// This variable source does not itself reach out to its entitySource. It produces its variables
+// by searching for BundleVariables that are produced by its 'inputVariableSource' and working out
+// which bundles correspond to which package and which gvks are provided by which bundle
+type CRDUniquenessConstraintsVariableSource struct {
+	inputVariableSource input.VariableSource
+}
+
+// NewCRDUniquenessConstraintsVariableSource creates a new instance of the CRDUniquenessConstraintsVariableSource.
+// its purpose if to provide variables with constraints that restrict the solutions to bundle sets where
+// no two bundles come from the same package and not two bundles provide the same gvk
+func NewCRDUniquenessConstraintsVariableSource(inputVariableSource input.VariableSource) *CRDUniquenessConstraintsVariableSource {
+	return &CRDUniquenessConstraintsVariableSource{
+		inputVariableSource: inputVariableSource,
+	}
+}
+
+func (g *CRDUniquenessConstraintsVariableSource) GetVariables(ctx context.Context, entitySource input.EntitySource) ([]deppy.Variable, error) {
+	variables, err := g.inputVariableSource.GetVariables(ctx, entitySource)
+	if err != nil {
+		return nil, err
+	}
+
+	// todo(perdasilva): better handle cases where a provided gvk is not found
+	//                   not all packages will necessarily export a CRD
+
+	pkgToBundleMap := map[string]map[deppy.Identifier]struct{}{}
+	gvkToBundleMap := map[string]map[deppy.Identifier]struct{}{}
+	for _, variable := range variables {
+		switch v := variable.(type) {
+		case *bundles_and_dependencies.BundleVariable:
+			bundleEntities := []*olmentity.BundleEntity{v.BundleEntity()}
+			bundleEntities = append(bundleEntities, v.Dependencies()...)
+			for _, bundleEntity := range bundleEntities {
+				// get bundleID package and update map
+				packageName, err := bundleEntity.PackageName()
+				if err != nil {
+					return nil, fmt.Errorf("error creating global constraints: %w", err)
+				}
+
+				if _, ok := pkgToBundleMap[packageName]; !ok {
+					pkgToBundleMap[packageName] = map[deppy.Identifier]struct{}{}
+				}
+				pkgToBundleMap[packageName][bundleEntity.ID] = struct{}{}
+
+				// get bundleID gvks and update map
+				exportedGVKs, err := bundleEntity.ProvidedGVKs()
+				if err != nil {
+					return nil, fmt.Errorf("error creating global constraints: %w", err)
+				}
+				for i := 0; i < len(exportedGVKs); i++ {
+					gvk := exportedGVKs[i].String()
+					if _, ok := gvkToBundleMap[gvk]; !ok {
+						gvkToBundleMap[gvk] = map[deppy.Identifier]struct{}{}
+					}
+					gvkToBundleMap[gvk][bundleEntity.ID] = struct{}{}
+				}
+			}
+		}
+	}
+
+	// create global constraint variables
+	for packageName, bundleIDMap := range pkgToBundleMap {
+		var bundleIDs []deppy.Identifier
+		for bundleID := range bundleIDMap {
+			bundleIDs = append(bundleIDs, bundleID)
+		}
+		varID := deppy.IdentifierFromString(fmt.Sprintf("%s package uniqueness", packageName))
+		variables = append(variables, NewBundleUniquenessVariable(varID, bundleIDs...))
+	}
+
+	for gvk, bundleIDMap := range gvkToBundleMap {
+		var bundleIDs []deppy.Identifier
+		for bundleID := range bundleIDMap {
+			bundleIDs = append(bundleIDs, bundleID)
+		}
+		varID := deppy.IdentifierFromString(fmt.Sprintf("%s gvk uniqueness", gvk))
+		variables = append(variables, NewBundleUniquenessVariable(varID, bundleIDs...))
+	}
+
+	return variables, nil
+}