feat: add cel language support (#483)

* feat: add cel language support

Signed-off-by: Charles-Edouard Brétéché <charles.edouard@nirmata.com>

* go mod

Signed-off-by: Charles-Edouard Brétéché <charles.edouard@nirmata.com>

* bindings

Signed-off-by: Charles-Edouard Brétéché <charles.edouard@nirmata.com>

* constant

Signed-off-by: Charles-Edouard Brétéché <charles.edouard@nirmata.com>

* fix

Signed-off-by: Charles-Edouard Brétéché <charles.edouard@nirmata.com>

* cel

Signed-off-by: Charles-Edouard Brétéché <charles.edouard@nirmata.com>

* cel binding

Signed-off-by: Charles-Edouard Brétéché <charles.edouard@nirmata.com>

* fix

Signed-off-by: Charles-Edouard Brétéché <charles.edouard@nirmata.com>

* templating

Signed-off-by: Charles-Edouard Brétéché <charles.edouard@nirmata.com>

* fix

Signed-off-by: Charles-Edouard Brétéché <charles.edouard@nirmata.com>

---------

Signed-off-by: Charles-Edouard Brétéché <charles.edouard@nirmata.com>

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/blang/semver/v4 v4.0.0
 	github.com/gin-contrib/cors v1.7.2
 	github.com/gin-gonic/gin v1.10.0
+	github.com/google/cel-go v0.17.8
 	github.com/google/go-cmp v0.6.0
 	github.com/jmespath-community/go-jmespath v1.1.2-0.20240117150817-e430401a2172
 	github.com/kyverno/pkg/ext v0.0.0-20240418121121-df8add26c55c
@@ -62,7 +63,6 @@ require (
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
 	github.com/golang/protobuf v1.5.4 // indirect
 	github.com/google/btree v1.1.2 // indirect
-	github.com/google/cel-go v0.17.8 // indirect
 	github.com/google/gnostic-models v0.6.9-0.20230804172637-c7be7c783f49 // indirect
 	github.com/google/gofuzz v1.2.0 // indirect
 	github.com/google/gxui v0.0.0-20151028112939-f85e0a97b3a4 // indirect

pkg/apis/policy/v1alpha1/assertion_tree.go

@@ -1,10 +1,8 @@
 package v1alpha1
 
 import (
-	"context"
-	"sync"
-
 	"github.com/kyverno/kyverno-json/pkg/core/assertion"
+	"github.com/kyverno/kyverno-json/pkg/core/templating"
 	"k8s.io/apimachinery/pkg/util/json"
 )
 
@@ -13,24 +11,20 @@ import (
 // +kubebuilder:validation:Type:=""
 // AssertionTree represents an assertion tree.
 type AssertionTree struct {
-	_tree      any
-	_assertion func() (assertion.Assertion, error)
+	_tree any
 }
 
 func NewAssertionTree(value any) AssertionTree {
 	return AssertionTree{
 		_tree: value,
-		_assertion: sync.OnceValues(func() (assertion.Assertion, error) {
-			return assertion.Parse(context.Background(), value)
-		}),
 	}
 }
 
-func (t *AssertionTree) Assertion() (assertion.Assertion, error) {
+func (t *AssertionTree) Assertion(compiler templating.Compiler) (assertion.Assertion, error) {
 	if t._tree == nil {
 		return nil, nil
 	}
-	return t._assertion()
+	return assertion.Parse(t._tree, compiler)
 }
 
 func (a *AssertionTree) MarshalJSON() ([]byte, error) {
@@ -44,13 +38,9 @@ func (a *AssertionTree) UnmarshalJSON(data []byte) error {
 		return err
 	}
 	a._tree = v
-	a._assertion = sync.OnceValues(func() (assertion.Assertion, error) {
-		return assertion.Parse(context.Background(), v)
-	})
 	return nil
 }
 
 func (in *AssertionTree) DeepCopyInto(out *AssertionTree) {
 	out._tree = deepCopy(in._tree)
-	out._assertion = in._assertion
 }

pkg/commands/jp/query/command.go

@@ -1,7 +1,6 @@
 package query
 
 import (
-	"context"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -11,7 +10,7 @@ import (
 
 	"github.com/jmespath-community/go-jmespath/pkg/parsing"
 	"github.com/kyverno/kyverno-json/pkg/command"
-	"github.com/kyverno/kyverno-json/pkg/engine/template"
+	"github.com/kyverno/kyverno-json/pkg/core/templating"
 	"github.com/spf13/cobra"
 	"sigs.k8s.io/yaml"
 )
@@ -156,7 +155,8 @@ func loadInput(cmd *cobra.Command, file string) (any, error) {
 }
 
 func evaluate(input any, query string) (any, error) {
-	result, err := template.ExecuteJP(context.Background(), query, input, nil)
+	compiler := templating.NewCompiler(templating.CompilerOptions{})
+	result, err := templating.ExecuteJP(query, input, nil, compiler)
 	if err != nil {
 		if syntaxError, ok := err.(parsing.SyntaxError); ok {
 			return nil, fmt.Errorf("%s\n%s", syntaxError, syntaxError.HighlightLocation())

pkg/commands/scan/command_test.go

@@ -24,6 +24,12 @@ func Test_Execute(t *testing.T) {
 		policies: []string{"../../../test/commands/scan/foo-bar/policy.yaml"},
 		out:      "../../../test/commands/scan/foo-bar/out.txt",
 		wantErr:  false,
+	}, {
+		name:     "cel",
+		payload:  "../../../test/commands/scan/cel/payload.yaml",
+		policies: []string{"../../../test/commands/scan/cel/policy.yaml"},
+		out:      "../../../test/commands/scan/cel/out.txt",
+		wantErr:  false,
 	}, {
 		name:     "wildcard",
 		payload:  "../../../test/commands/scan/wildcard/payload.json",

pkg/commands/scan/options.go

@@ -7,7 +7,7 @@ import (
 	"strings"
 
 	"github.com/kyverno/kyverno-json/pkg/apis/policy/v1alpha1"
-	"github.com/kyverno/kyverno-json/pkg/engine/template"
+	"github.com/kyverno/kyverno-json/pkg/core/templating"
 	jsonengine "github.com/kyverno/kyverno-json/pkg/json-engine"
 	"github.com/kyverno/kyverno-json/pkg/payload"
 	"github.com/kyverno/kyverno-json/pkg/policy"
@@ -76,8 +76,9 @@ func (c *options) run(cmd *cobra.Command, _ []string) error {
 		return errors.New("payload is `null`")
 	}
 	out.println("Pre processing ...")
+	compiler := templating.NewCompiler(templating.CompilerOptions{})
 	for _, preprocessor := range c.preprocessors {
-		result, err := template.ExecuteJP(context.Background(), preprocessor, payload, nil)
+		result, err := templating.ExecuteJP(preprocessor, payload, nil, compiler)
 		if err != nil {
 			return err
 		}

pkg/core/assertion/assertion.go

@@ -1,58 +1,56 @@
 package assertion
 
 import (
-	"context"
 	"errors"
 	"fmt"
 	"reflect"
 	"sync"
 
 	"github.com/jmespath-community/go-jmespath/pkg/binding"
-	"github.com/jmespath-community/go-jmespath/pkg/parsing"
 	"github.com/kyverno/kyverno-json/pkg/core/expression"
 	"github.com/kyverno/kyverno-json/pkg/core/projection"
+	"github.com/kyverno/kyverno-json/pkg/core/templating"
 	"github.com/kyverno/kyverno-json/pkg/engine/match"
-	"github.com/kyverno/kyverno-json/pkg/engine/template"
 	reflectutils "github.com/kyverno/kyverno-json/pkg/utils/reflect"
 	"k8s.io/apimachinery/pkg/util/validation/field"
 )
 
 type Assertion interface {
-	Assert(context.Context, *field.Path, any, binding.Bindings, ...template.Option) (field.ErrorList, error)
+	Assert(*field.Path, any, binding.Bindings) (field.ErrorList, error)
 }
 
-func Parse(ctx context.Context, assertion any) (node, error) {
+func Parse(assertion any, compiler templating.Compiler) (node, error) {
 	switch reflectutils.GetKind(assertion) {
 	case reflect.Slice:
-		return parseSlice(ctx, assertion)
+		return parseSlice(assertion, compiler)
 	case reflect.Map:
-		return parseMap(ctx, assertion)
+		return parseMap(assertion, compiler)
 	default:
-		return parseScalar(ctx, assertion)
+		return parseScalar(assertion, compiler)
 	}
 }
 
 // node implements the Assertion interface using a delegate func
-type node func(ctx context.Context, path *field.Path, value any, bindings binding.Bindings, opts ...template.Option) (field.ErrorList, error)
+type node func(path *field.Path, value any, bindings binding.Bindings) (field.ErrorList, error)
 
-func (n node) Assert(ctx context.Context, path *field.Path, value any, bindings binding.Bindings, opts ...template.Option) (field.ErrorList, error) {
-	return n(ctx, path, value, bindings, opts...)
+func (n node) Assert(path *field.Path, value any, bindings binding.Bindings) (field.ErrorList, error) {
+	return n(path, value, bindings)
 }
 
 // parseSlice is the assertion represented by a slice.
 // it first compares the length of the analysed resource with the length of the descendants.
 // if lengths match all descendants are evaluated with their corresponding items.
-func parseSlice(ctx context.Context, assertion any) (node, error) {
+func parseSlice(assertion any, compiler templating.Compiler) (node, error) {
 	var assertions []node
 	valueOf := reflect.ValueOf(assertion)
 	for i := 0; i < valueOf.Len(); i++ {
-		sub, err := Parse(ctx, valueOf.Index(i).Interface())
+		sub, err := Parse(valueOf.Index(i).Interface(), compiler)
 		if err != nil {
 			return nil, err
 		}
 		assertions = append(assertions, sub)
 	}
-	return func(ctx context.Context, path *field.Path, value any, bindings binding.Bindings, opts ...template.Option) (field.ErrorList, error) {
+	return func(path *field.Path, value any, bindings binding.Bindings) (field.ErrorList, error) {
 		var errs field.ErrorList
 		if value == nil {
 			errs = append(errs, field.Invalid(path, value, "value is null"))
@@ -64,7 +62,7 @@ func parseSlice(ctx context.Context, assertion any) (node, error) {
 				errs = append(errs, field.Invalid(path, value, "lengths of slices don't match"))
 			} else {
 				for i := range assertions {
-					if _errs, err := assertions[i].Assert(ctx, path.Index(i), valueOf.Index(i).Interface(), bindings, opts...); err != nil {
+					if _errs, err := assertions[i].Assert(path.Index(i), valueOf.Index(i).Interface(), bindings); err != nil {
 						return nil, err
 					} else {
 						errs = append(errs, _errs...)
@@ -78,7 +76,7 @@ func parseSlice(ctx context.Context, assertion any) (node, error) {
 
 // parseMap is the assertion represented by a map.
 // it is responsible for projecting the analysed resource and passing the result to the descendant
-func parseMap(ctx context.Context, assertion any) (node, error) {
+func parseMap(assertion any, compiler templating.Compiler) (node, error) {
 	assertions := map[any]struct {
 		projection.Projection
 		node
@@ -87,16 +85,16 @@ func parseMap(ctx context.Context, assertion any) (node, error) {
 	for iter.Next() {
 		key := iter.Key().Interface()
 		value := iter.Value().Interface()
-		assertion, err := Parse(ctx, value)
+		assertion, err := Parse(value, compiler)
 		if err != nil {
 			return nil, err
 		}
 		entry := assertions[key]
 		entry.node = assertion
-		entry.Projection = projection.Parse(key)
+		entry.Projection = projection.Parse(key, compiler)
 		assertions[key] = entry
 	}
-	return func(ctx context.Context, path *field.Path, value any, bindings binding.Bindings, opts ...template.Option) (field.ErrorList, error) {
+	return func(path *field.Path, value any, bindings binding.Bindings) (field.ErrorList, error) {
 		var errs field.ErrorList
 		// if we assert against an empty object, value is expected to be not nil
 		if len(assertions) == 0 {
@@ -106,7 +104,7 @@ func parseMap(ctx context.Context, assertion any) (node, error) {
 			return errs, nil
 		}
 		for k, v := range assertions {
-			projected, found, err := v.Projection.Handler(ctx, value, bindings, opts...)
+			projected, found, err := v.Projection.Handler(value, bindings)
 			if err != nil {
 				return nil, field.InternalError(path.Child(fmt.Sprint(k)), err)
 			} else if !found {
@@ -124,7 +122,7 @@ func parseMap(ctx context.Context, assertion any) (node, error) {
 							if v.Projection.ForeachName != "" {
 								bindings = bindings.Register("$"+v.Projection.ForeachName, binding.NewBinding(i))
 							}
-							if _errs, err := v.Assert(ctx, path.Child(fmt.Sprint(k)).Index(i), valueOf.Index(i).Interface(), bindings, opts...); err != nil {
+							if _errs, err := v.Assert(path.Child(fmt.Sprint(k)).Index(i), valueOf.Index(i).Interface(), bindings); err != nil {
 								return nil, err
 							} else {
 								errs = append(errs, _errs...)
@@ -138,7 +136,7 @@ func parseMap(ctx context.Context, assertion any) (node, error) {
 							if v.Projection.ForeachName != "" {
 								bindings = bindings.Register("$"+v.Projection.ForeachName, binding.NewBinding(key))
 							}
-							if _errs, err := v.Assert(ctx, path.Child(fmt.Sprint(k)).Key(fmt.Sprint(key)), iter.Value().Interface(), bindings, opts...); err != nil {
+							if _errs, err := v.Assert(path.Child(fmt.Sprint(k)).Key(fmt.Sprint(key)), iter.Value().Interface(), bindings); err != nil {
 								return nil, err
 							} else {
 								errs = append(errs, _errs...)
@@ -148,7 +146,7 @@ func parseMap(ctx context.Context, assertion any) (node, error) {
 						return nil, field.TypeInvalid(path.Child(fmt.Sprint(k)), projected, "expected a slice or a map")
 					}
 				} else {
-					if _errs, err := v.Assert(ctx, path.Child(fmt.Sprint(k)), projected, bindings, opts...); err != nil {
+					if _errs, err := v.Assert(path.Child(fmt.Sprint(k)), projected, bindings); err != nil {
 						return nil, err
 					} else {
 						errs = append(errs, _errs...)
@@ -163,8 +161,8 @@ func parseMap(ctx context.Context, assertion any) (node, error) {
 // parseScalar is the assertion represented by a leaf.
 // it receives a value and compares it with an expected value.
 // the expected value can be the result of an expression.
-func parseScalar(_ context.Context, assertion any) (node, error) {
-	var project func(ctx context.Context, value any, bindings binding.Bindings, opts ...template.Option) (any, error)
+func parseScalar(assertion any, compiler templating.Compiler) (node, error) {
+	var project func(value any, bindings binding.Bindings) (any, error)
 	switch typed := assertion.(type) {
 	case string:
 		expr := expression.Parse(typed)
@@ -176,34 +174,39 @@ func parseScalar(_ context.Context, assertion any) (node, error) {
 		}
 		switch expr.Engine {
 		case expression.EngineJP:
-			parse := sync.OnceValues(func() (parsing.ASTNode, error) {
-				parser := parsing.NewParser()
-				return parser.Parse(expr.Statement)
+			parse := sync.OnceValues(func() (templating.Program, error) {
+				return compiler.CompileJP(expr.Statement)
 			})
-			project = func(ctx context.Context, value any, bindings binding.Bindings, opts ...template.Option) (any, error) {
-				ast, err := parse()
+			project = func(value any, bindings binding.Bindings) (any, error) {
+				program, err := parse()
 				if err != nil {
 					return nil, err
 				}
-				return template.ExecuteAST(ctx, ast, value, bindings, opts...)
+				return program(value, bindings)
 			}
 		case expression.EngineCEL:
-			return nil, errors.New("engine not supported")
+			project = func(value any, bindings binding.Bindings) (any, error) {
+				program, err := compiler.CompileCEL(expr.Statement)
+				if err != nil {
+					return nil, err
+				}
+				return program(value, bindings)
+			}
 		default:
 			assertion = expr.Statement
 		}
 	}
-	return func(ctx context.Context, path *field.Path, value any, bindings binding.Bindings, opts ...template.Option) (field.ErrorList, error) {
+	return func(path *field.Path, value any, bindings binding.Bindings) (field.ErrorList, error) {
 		expected := assertion
 		if project != nil {
-			projected, err := project(ctx, value, bindings, opts...)
+			projected, err := project(value, bindings)
 			if err != nil {
 				return nil, field.InternalError(path, err)
 			}
 			expected = projected
 		}
 		var errs field.ErrorList
-		if match, err := match.Match(ctx, expected, value); err != nil {
+		if match, err := match.Match(expected, value); err != nil {
 			return nil, field.InternalError(path, err)
 		} else if !match {
 			errs = append(errs, field.Invalid(path, value, expectValueMessage(expected)))

pkg/core/assertion/assertion_test.go

@@ -1,10 +1,10 @@
 package assertion
 
 import (
-	"context"
 	"testing"
 
 	"github.com/jmespath-community/go-jmespath/pkg/binding"
+	"github.com/kyverno/kyverno-json/pkg/core/templating"
 	tassert "github.com/stretchr/testify/assert"
 	"k8s.io/apimachinery/pkg/util/validation/field"
 )
@@ -48,9 +48,10 @@ func TestAssert(t *testing.T) {
 	}}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			parsed, err := Parse(context.TODO(), tt.assertion)
+			compiler := templating.NewCompiler(templating.CompilerOptions{})
+			parsed, err := Parse(tt.assertion, compiler)
 			tassert.NoError(t, err)
-			got, err := parsed.Assert(context.TODO(), nil, tt.value, tt.bindings)
+			got, err := parsed.Assert(nil, tt.value, tt.bindings)
 			if tt.wantErr {
 				tassert.Error(t, err)
 			} else {