policy validation: refactoring

pkg/engine/anchor.go

@@ -5,6 +5,7 @@ import (
 	"strconv"
 
 	"github.com/golang/glog"
+	"github.com/nirmata/kyverno/pkg/engine/anchor"
 )
 
 //ValidationHandler for element processes
@@ -15,19 +16,20 @@ type ValidationHandler interface {
 //CreateElementHandler factory to process elements
 func CreateElementHandler(element string, pattern interface{}, path string) ValidationHandler {
 	switch {
-	case isConditionAnchor(element):
+	case anchor.IsConditionAnchor(element):
 		return NewConditionAnchorHandler(element, pattern, path)
-	case isExistanceAnchor(element):
+	case anchor.IsExistanceAnchor(element):
 		return NewExistanceHandler(element, pattern, path)
-	case isEqualityAnchor(element):
+	case anchor.IsEqualityAnchor(element):
 		return NewEqualityHandler(element, pattern, path)
-	case isNegationAnchor(element):
+	case anchor.IsNegationAnchor(element):
 		return NewNegationHandler(element, pattern, path)
 	default:
 		return NewDefaultHandler(element, pattern, path)
 	}
 }
 
+//NewNegationHandler returns instance of negation handler
 func NewNegationHandler(anchor string, pattern interface{}, path string) ValidationHandler {
 	return NegationHandler{
 		anchor:  anchor,
@@ -56,6 +58,7 @@ func (nh NegationHandler) Handle(resourceMap map[string]interface{}, originPatte
 	return "", nil
 }
 
+//NewEqualityHandler returens instance of equality handler
 func NewEqualityHandler(anchor string, pattern interface{}, path string) ValidationHandler {
 	return EqualityHandler{
 		anchor:  anchor,
@@ -217,7 +220,7 @@ func getAnchorsResourcesFromMap(patternMap map[string]interface{}) (map[string]i
 	anchors := map[string]interface{}{}
 	resources := map[string]interface{}{}
 	for key, value := range patternMap {
-		if isConditionAnchor(key) || isExistanceAnchor(key) || isEqualityAnchor(key) || isNegationAnchor(key) {
+		if anchor.IsConditionAnchor(key) || anchor.IsExistanceAnchor(key) || anchor.IsEqualityAnchor(key) || anchor.IsNegationAnchor(key) {
 			anchors[key] = value
 			continue
 		}

pkg/engine/anchor/utils.go

@@ -0,0 +1,54 @@
+package anchor
+
+// Anchor function type
+type IsAnchor func(str string) bool
+
+func IsConditionAnchor(str string) bool {
+	if len(str) < 2 {
+		return false
+	}
+
+	return (str[0] == '(' && str[len(str)-1] == ')')
+}
+
+func IsNegationAnchor(str string) bool {
+	left := "X("
+	right := ")"
+	if len(str) < len(left)+len(right) {
+		return false
+	}
+	//TODO: trim spaces ?
+	return (str[:len(left)] == left && str[len(str)-len(right):] == right)
+}
+
+func IsAddingAnchor(key string) bool {
+	const left = "+("
+	const right = ")"
+
+	if len(key) < len(left)+len(right) {
+		return false
+	}
+
+	return left == key[:len(left)] && right == key[len(key)-len(right):]
+}
+
+func IsEqualityAnchor(str string) bool {
+	left := "=("
+	right := ")"
+	if len(str) < len(left)+len(right) {
+		return false
+	}
+	//TODO: trim spaces ?
+	return (str[:len(left)] == left && str[len(str)-len(right):] == right)
+}
+
+func IsExistanceAnchor(str string) bool {
+	left := "^("
+	right := ")"
+
+	if len(str) < len(left)+len(right) {
+		return false
+	}
+
+	return (str[:len(left)] == left && str[len(str)-len(right):] == right)
+}

pkg/engine/anchor/utils_test.go

@@ -0,0 +1,58 @@
+package anchor
+
+import (
+	"testing"
+
+	"gotest.tools/assert"
+)
+
+func TestWrappedWithParentheses_StringIsWrappedWithParentheses(t *testing.T) {
+	str := "(something)"
+	assert.Assert(t, IsConditionAnchor(str))
+}
+
+func TestWrappedWithParentheses_StringHasOnlyParentheses(t *testing.T) {
+	str := "()"
+	assert.Assert(t, IsConditionAnchor(str))
+}
+
+func TestWrappedWithParentheses_StringHasNoParentheses(t *testing.T) {
+	str := "something"
+	assert.Assert(t, !IsConditionAnchor(str))
+}
+
+func TestWrappedWithParentheses_StringHasLeftParentheses(t *testing.T) {
+	str := "(something"
+	assert.Assert(t, !IsConditionAnchor(str))
+}
+
+func TestWrappedWithParentheses_StringHasRightParentheses(t *testing.T) {
+	str := "something)"
+	assert.Assert(t, !IsConditionAnchor(str))
+}
+
+func TestWrappedWithParentheses_StringParenthesesInside(t *testing.T) {
+	str := "so)m(et(hin)g"
+	assert.Assert(t, !IsConditionAnchor(str))
+}
+
+func TestWrappedWithParentheses_Empty(t *testing.T) {
+	str := ""
+	assert.Assert(t, !IsConditionAnchor(str))
+}
+
+func TestIsExistanceAnchor_Yes(t *testing.T) {
+	assert.Assert(t, IsExistanceAnchor("^(abc)"))
+}
+
+func TestIsExistanceAnchor_NoRightBracket(t *testing.T) {
+	assert.Assert(t, !IsExistanceAnchor("^(abc"))
+}
+
+func TestIsExistanceAnchor_OnlyHat(t *testing.T) {
+	assert.Assert(t, !IsExistanceAnchor("^abc"))
+}
+
+func TestIsExistanceAnchor_ConditionAnchor(t *testing.T) {
+	assert.Assert(t, !IsExistanceAnchor("(abc)"))
+}

pkg/engine/generation.go

@@ -38,7 +38,7 @@ func Generate(client *client.Client, policy kyverno.ClusterPolicy, ns unstructur
 		response.PolicyResponse.RulesAppliedCount++
 	}
 	for _, rule := range policy.Spec.Rules {
-		if rule.Generation == (kyverno.Generation{}) {
+		if !rule.HasGenerate() {
 			continue
 		}
 		glog.V(4).Infof("applying policy %s generate rule %s on resource %s/%s/%s", policy.Name, rule.Name, ns.GetKind(), ns.GetNamespace(), ns.GetName())

pkg/engine/mutation.go

@@ -37,7 +37,7 @@ func Mutate(policy kyverno.ClusterPolicy, resource unstructured.Unstructured) (r
 
 	for _, rule := range policy.Spec.Rules {
 		//TODO: to be checked before calling the resources as well
-		if reflect.DeepEqual(rule.Mutation, kyverno.Mutation{}) {
+		if !rule.HasMutate() {
 			continue
 		}
 		// check if the resource satisfies the filter conditions defined in the rule

pkg/engine/overlay.go

@@ -14,6 +14,7 @@ import (
 
 	jsonpatch "github.com/evanphx/json-patch"
 	kyverno "github.com/nirmata/kyverno/pkg/api/kyverno/v1alpha1"
+	"github.com/nirmata/kyverno/pkg/engine/anchor"
 )
 
 // processOverlay processes validation patterns on the resource
@@ -148,7 +149,7 @@ func applyOverlayToMap(resourceMap, overlayMap map[string]interface{}, path stri
 	for key, value := range overlayMap {
 		// skip anchor element because it has condition, not
 		// the value that must replace resource value
-		if isConditionAnchor(key) {
+		if anchor.IsConditionAnchor(key) {
 			continue
 		}
 
@@ -156,7 +157,7 @@ func applyOverlayToMap(resourceMap, overlayMap map[string]interface{}, path stri
 		currentPath := path + noAnchorKey + "/"
 		resourcePart, ok := resourceMap[noAnchorKey]
 
-		if ok && !isAddingAnchor(key) {
+		if ok && !anchor.IsAddingAnchor(key) {
 			// Key exists - go down through the overlay and resource trees
 			patches, err := applyOverlay(resourcePart, value, currentPath)
 			if err != nil {

pkg/engine/overlayCondition.go

@@ -4,6 +4,7 @@ import (
 	"reflect"
 
 	"github.com/golang/glog"
+	"github.com/nirmata/kyverno/pkg/engine/anchor"
 )
 
 func meetConditions(resource, overlay interface{}) bool {
@@ -51,7 +52,7 @@ func checkConditionOnMap(resourceMap, overlayMap map[string]interface{}) bool {
 	for key, value := range overlayMap {
 		resourcePart, ok := resourceMap[key]
 
-		if ok && !isAddingAnchor(key) {
+		if ok && !anchor.IsAddingAnchor(key) {
 			if !meetConditions(resourcePart, value) {
 				return false
 			}

pkg/engine/policy/utils.go

@@ -1,26 +1,5 @@
 package policy
 
-import (
-	"errors"
-	"fmt"
-	"strings"
-)
-
-// joinErrs joins the list of error into single error
-// adds a new line between errors
-func joinErrs(errs []error) error {
-	if len(errs) == 0 {
-		return nil
-	}
-
-	res := "\n"
-	for _, err := range errs {
-		res = fmt.Sprintf(res + err.Error() + "\n")
-	}
-
-	return errors.New(res)
-}
-
 //Contains Check if strint is contained in a list of string
 func containString(list []string, element string) bool {
 	for _, e := range list {
@@ -30,73 +9,3 @@ func containString(list []string, element string) bool {
 	}
 	return false
 }
-
-// hasExistingAnchor checks if str has existing anchor
-// strip anchor if necessary
-func hasExistingAnchor(str string) (bool, string) {
-	left := "^("
-	right := ")"
-
-	if len(str) < len(left)+len(right) {
-		return false, str
-	}
-
-	return (str[:len(left)] == left && str[len(str)-len(right):] == right), str[len(left) : len(str)-len(right)]
-}
-
-// hasValidAnchors checks str has the valid anchor
-// mutate: (), +()
-// validate: (), ^(), =(), X()
-// generate: none
-// invalid anchors: ~(),!()
-func hasValidAnchors(anchors []anchor, str string) (bool, string) {
-	if wrappedWithAttributes(str) {
-		return mustWrapWithAnchors(anchors, str)
-	}
-
-	return true, str
-}
-
-// mustWrapWithAnchors validates str must wrap with
-// at least one given anchor
-func mustWrapWithAnchors(anchors []anchor, str string) (bool, string) {
-	for _, a := range anchors {
-		if str[:len(a.left)] == a.left && str[len(str)-len(a.right):] == a.right {
-			return true, str[len(a.left) : len(str)-len(a.right)]
-		}
-	}
-
-	return false, str
-}
-
-func wrappedWithAttributes(str string) bool {
-	if len(str) < 2 {
-		return false
-	}
-
-	if (str[0] == '(' && str[len(str)-1] == ')') ||
-		(str[0] == '^' || str[0] == '+' || str[0] == '=' || str[0] == 'X' || str[0] == '!' || str[0] == '~') &&
-			(str[1] == '(' && str[len(str)-1] == ')') {
-		return true
-	}
-
-	return false
-}
-
-func joinAnchors(anchorPatterns []anchor) string {
-	var res []string
-	for _, a := range anchorPatterns {
-		res = append(res, a.left+a.right)
-	}
-
-	return strings.Join(res, " || ")
-}
-
-func hasNegationAnchor(str string) (bool, string) {
-	left := "X("
-	right := ")"
-	if len(str) < len(left)+len(right) {
-		return false, str
-	}
-	return (str[:len(left)] == left && str[len(str)-len(right):] == right), str[len(left) : len(str)-len(right)]
-}

pkg/engine/policy/validate.go

@@ -4,89 +4,84 @@ import (
 	"errors"
 	"fmt"
 	"reflect"
+	"regexp"
 	"strconv"
 
-	"github.com/golang/glog"
 	kyverno "github.com/nirmata/kyverno/pkg/api/kyverno/v1alpha1"
+	"github.com/nirmata/kyverno/pkg/engine/anchor"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
-type anchor struct {
-	left  string
-	right string
-}
-
-var (
-	conditionalAnchor = anchor{left: "(", right: ")"}
-	existingAnchor    = anchor{left: "^(", right: ")"}
-	equalityAnchor    = anchor{left: "=(", right: ")"}
-	plusAnchor        = anchor{left: "+(", right: ")"}
-	negationAnchor    = anchor{left: "X(", right: ")"}
-)
-
+// Validate does some initial check to verify some conditions
+// - One operation per rule
+// - ResourceDescription mandatory checks
 func Validate(p kyverno.ClusterPolicy) error {
-	var errs []error
-
-	if err := validateUniqueRuleName(p); err != nil {
-		errs = append(errs, fmt.Errorf("- Invalid Policy '%s':", p.Name))
-		errs = append(errs, err)
+	if path, err := validateUniqueRuleName(p); err != nil {
+		return fmt.Errorf("path: spec.%s: %v", path, err)
 	}
 
-	for _, rule := range p.Spec.Rules {
-		if ruleErrs := validateRule(rule); len(ruleErrs) != 0 {
-			errs = append(errs, fmt.Errorf("- invalid rule '%s':", rule.Name))
-			errs = append(errs, ruleErrs...)
+	for i, rule := range p.Spec.Rules {
+		// only one type of rule is allowed per rule
+		if err := validateRuleType(rule); err != nil {
+			return fmt.Errorf("path: spec.rules[%d]: %v", i, err)
 		}
-	}
 
-	return joinErrs(errs)
-}
-
-// ValidateUniqueRuleName checks if the rule names are unique across a policy
-func validateUniqueRuleName(p kyverno.ClusterPolicy) error {
-	var ruleNames []string
-
-	for _, rule := range p.Spec.Rules {
-		if containString(ruleNames, rule.Name) {
-			return fmt.Errorf(`duplicate rule name: '%s'`, rule.Name)
+		// validate resource description
+		if path, err := validateResources(rule); err != nil {
+			return fmt.Errorf("path: spec.rules[%d].%s: %v", i, path, err)
+		}
+		// validate rule types
+		// only one type of rule is allowed per rule
+		if err := validateRuleType(rule); err != nil {
+			// as there are more than 1 operation in rule, not need to evaluate it further
+			return fmt.Errorf("path: spec.rules[%d]: %v", i, err)
+		}
+		// Operation Validation
+		// Mutation
+		if rule.HasMutate() {
+			if path, err := validateMutation(rule.Mutation); err != nil {
+				return fmt.Errorf("path: spec.rules[%d].mutate.%s.: %v", i, path, err)
+			}
+		}
+		// Validation
+		if rule.HasValidate() {
+			if path, err := validateValidation(rule.Validation); err != nil {
+				return fmt.Errorf("path: spec.rules[%d].validate.%s.: %v", i, path, err)
+			}
+		}
+		// Generation
+		if rule.HasGenerate() {
+			if path, err := validateGeneration(rule.Generation); err != nil {
+				return fmt.Errorf("path: spec.rules[%d].generate.%s.: %v", i, path, err)
+			}
 		}
-		ruleNames = append(ruleNames, rule.Name)
 	}
 	return nil
 }
 
-// Validate checks if rule is not empty and all substructures are valid
-func validateRule(r kyverno.Rule) []error {
-	var errs []error
-
-	// only one type of rule is allowed per rule
-	if err := validateRuleType(r); err != nil {
-		errs = append(errs, err)
+func validateResources(rule kyverno.Rule) (string, error) {
+	// matched resources
+	if path, err := validateMatchedResourceDescription(rule.MatchResources.ResourceDescription); err != nil {
+		return fmt.Sprintf("resources.%s", path), err
 	}
-
-	// validate resource description block
-	if err := validateMatchedResourceDescription(r.MatchResources.ResourceDescription); err != nil {
-		errs = append(errs, fmt.Errorf("error in match block, %v", err))
+	// exclude resources
+	if path, err := validateExcludeResourceDescription(rule.ExcludeResources.ResourceDescription); err != nil {
+		return fmt.Sprintf("resources.%s", path), err
 	}
+	return "", nil
+}
 
-	if err := validateResourceDescription(r.ExcludeResources.ResourceDescription); err != nil {
-		errs = append(errs, fmt.Errorf("error in exclude block, %v", err))
+// ValidateUniqueRuleName checks if the rule names are unique across a policy
+func validateUniqueRuleName(p kyverno.ClusterPolicy) (string, error) {
+	var ruleNames []string
+
+	for i, rule := range p.Spec.Rules {
+		if containString(ruleNames, rule.Name) {
+			return fmt.Sprintf("rule[%d]", i), fmt.Errorf(`duplicate rule name: '%s'`, rule.Name)
+		}
+		ruleNames = append(ruleNames, rule.Name)
 	}
-
-	// validate anchors on mutate
-	if mErrs := validateMutation(r.Mutation); len(mErrs) != 0 {
-		errs = append(errs, mErrs...)
-	}
-
-	if vErrs := validateValidation(r.Validation); len(vErrs) != 0 {
-		errs = append(errs, vErrs...)
-	}
-
-	if err := validateGeneration(r.Generation); err != nil {
-		errs = append(errs, err)
-	}
-
-	return errs
+	return "", nil
 }
 
 // validateRuleType checks only one type of rule is defined per rule
@@ -104,7 +99,7 @@ func validateRuleType(r kyverno.Rule) error {
 	}()
 
 	if operationCount == 0 {
-		return fmt.Errorf("no operation defined in the rule '%s'.(supported operations: mutation,validation,generation,query)", r.Name)
+		return fmt.Errorf("no operation defined in the rule '%s'.(supported operations: mutation,validation,generation)", r.Name)
 	} else if operationCount != 1 {
 		return fmt.Errorf("multiple operations defined in the rule '%s', only one type of operation is allowed per rule", r.Name)
 	}
@@ -116,16 +111,31 @@ func validateRuleType(r kyverno.Rule) error {
 // Returns error if
 // - kinds is empty array in matched resource block, i.e. kinds: []
 // - selector is invalid
-func validateMatchedResourceDescription(rd kyverno.ResourceDescription) error {
+func validateMatchedResourceDescription(rd kyverno.ResourceDescription) (string, error) {
 	if reflect.DeepEqual(rd, kyverno.ResourceDescription{}) {
-		return nil
+		return "", fmt.Errorf("match resources not specified")
 	}
 
 	if len(rd.Kinds) == 0 {
-		return errors.New("field Kind is not specified")
+		return "match", fmt.Errorf("kind is mandatory")
 	}
 
-	return validateResourceDescription(rd)
+	if err := validateResourceDescription(rd); err != nil {
+		return "match", err
+	}
+
+	return "", nil
+}
+
+func validateExcludeResourceDescription(rd kyverno.ResourceDescription) (string, error) {
+	if reflect.DeepEqual(rd, kyverno.ResourceDescription{}) {
+		// exclude is not mandatory
+		return "", nil
+	}
+	if err := validateResourceDescription(rd); err != nil {
+		return "exclude", err
+	}
+	return "", nil
 }
 
 // validateResourceDescription returns error if selector is invalid
@@ -144,22 +154,23 @@ func validateResourceDescription(rd kyverno.ResourceDescription) error {
 	return nil
 }
 
-func validateMutation(m kyverno.Mutation) []error {
-	var errs []error
+func validateMutation(m kyverno.Mutation) (string, error) {
+	// JSON Patches
 	if len(m.Patches) != 0 {
-		for _, patch := range m.Patches {
-			err := validatePatch(patch)
-			errs = append(errs, err)
+		for i, patch := range m.Patches {
+			if err := validatePatch(patch); err != nil {
+				return fmt.Sprintf("patch[%d]", i), err
+			}
 		}
 	}
-
+	// Overlay
 	if m.Overlay != nil {
-		_, err := validateAnchors([]anchor{conditionalAnchor, plusAnchor}, m.Overlay, "/")
+		path, err := validatePattern(m.Overlay, "/", []anchor.IsAnchor{anchor.IsConditionAnchor, anchor.IsAddingAnchor})
 		if err != nil {
-			errs = append(errs, err)
+			return path, err
 		}
 	}
-	return errs
+	return "", nil
 }
 
 // Validate if all mandatory PolicyPatch fields are set
@@ -167,7 +178,6 @@ func validatePatch(pp kyverno.Patch) error {
 	if pp.Path == "" {
 		return errors.New("JSONPatch field 'path' is mandatory")
 	}
-
 	if pp.Operation == "add" || pp.Operation == "replace" {
 		if pp.Value == nil {
 			return fmt.Errorf("JSONPatch field 'value' is mandatory for operation '%s'", pp.Operation)
@@ -181,151 +191,154 @@ func validatePatch(pp kyverno.Patch) error {
 	return fmt.Errorf("Unsupported JSONPatch operation '%s'", pp.Operation)
 }
 
-func validateValidation(v kyverno.Validation) []error {
-	var errs []error
-
+func validateValidation(v kyverno.Validation) (string, error) {
 	if err := validateOverlayPattern(v); err != nil {
-		errs = append(errs, err)
+		// no need to proceed ahead
+		return "", err
 	}
 
 	if v.Pattern != nil {
-		if _, err := validateAnchors([]anchor{conditionalAnchor, existingAnchor, equalityAnchor, negationAnchor}, v.Pattern, "/"); err != nil {
-			errs = append(errs, err)
+		if path, err := validatePattern(v.Pattern, "/", []anchor.IsAnchor{anchor.IsConditionAnchor, anchor.IsExistanceAnchor, anchor.IsEqualityAnchor, anchor.IsNegationAnchor}); err != nil {
+			return fmt.Sprintf("pattern.%s", path), err
 		}
 	}
 
 	if len(v.AnyPattern) != 0 {
-		for _, p := range v.AnyPattern {
-			if _, err := validateAnchors([]anchor{conditionalAnchor, existingAnchor, equalityAnchor, negationAnchor}, p, "/"); err != nil {
-				errs = append(errs, err)
+		for i, pattern := range v.AnyPattern {
+			if path, err := validatePattern(pattern, "/", []anchor.IsAnchor{anchor.IsConditionAnchor, anchor.IsExistanceAnchor, anchor.IsEqualityAnchor, anchor.IsNegationAnchor}); err != nil {
+				return fmt.Sprintf("anyPattern[%d].%s", i, path), err
 			}
 		}
 	}
-
-	return errs
+	return "", nil
 }
 
 // validateOverlayPattern checks one of pattern/anyPattern must exist
 func validateOverlayPattern(v kyverno.Validation) error {
-	if reflect.DeepEqual(v, kyverno.Validation{}) {
-		return nil
-	}
-
 	if v.Pattern == nil && len(v.AnyPattern) == 0 {
-		return fmt.Errorf("neither pattern nor anyPattern found")
+		return fmt.Errorf("a pattern or anyPattern must be specified")
 	}
 
 	if v.Pattern != nil && len(v.AnyPattern) != 0 {
-		return fmt.Errorf("either pattern or anyPattern is allowed")
+		return fmt.Errorf("only one operation allowed per validation rule(pattern or anyPattern)")
 	}
 
 	return nil
 }
 
 // Validate returns error if generator is configured incompletely
-func validateGeneration(gen kyverno.Generation) error {
-	if reflect.DeepEqual(gen, kyverno.Generation{}) {
-		return nil
-	}
+func validateGeneration(gen kyverno.Generation) (string, error) {
 
 	if gen.Data == nil && gen.Clone == (kyverno.CloneFrom{}) {
-		return fmt.Errorf("neither data nor clone (source) of %s is specified", gen.Kind)
+		return "", fmt.Errorf("clone or data are required")
 	}
 	if gen.Data != nil && gen.Clone != (kyverno.CloneFrom{}) {
-		return fmt.Errorf("both data nor clone (source) of %s are specified", gen.Kind)
+		return "", fmt.Errorf("only one operation allowed per generate rule(data or clone)")
 	}
-
-	if gen.Data != nil {
-		if _, err := validateAnchors(nil, gen.Data, "/"); err != nil {
-			return fmt.Errorf("anchors are not allowed on generate pattern data: %v", err)
-		}
+	// check kind is non empty
+	// check name is non empty
+	if gen.Name == "" {
+		return "name", fmt.Errorf("name cannot be empty")
+	}
+	if gen.Kind == "" {
+		return "kind", fmt.Errorf("kind cannot be empty")
 	}
-
 	if !reflect.DeepEqual(gen.Clone, kyverno.CloneFrom{}) {
-		if _, err := validateAnchors(nil, gen.Clone, ""); err != nil {
-			return fmt.Errorf("invalid character found on pattern clone: %v", err)
+		if path, err := validateClone(gen.Clone); err != nil {
+			return fmt.Sprintf("clone.%s", path), err
 		}
 	}
-
-	return nil
+	if gen.Data != nil {
+		//TODO: is this required ?? as anchors can only be on pattern and not resource
+		// we can add this check by not sure if its needed here
+		if path, err := validatePattern(gen.Data, "/", []anchor.IsAnchor{}); err != nil {
+			return fmt.Sprintf("data.%s", path), fmt.Errorf("anchors not supported on generate resoruces: %v", err)
+		}
+	}
+	return "", nil
 }
 
-// validateAnchors validates:
-// 1. existing acnchor must define on array
-// 2. anchors in mutation must be one of: (), +()
-// 3. anchors in validate must be one of: (), ^(), =(), X()
-// 4. no anchor is allowed in generate
-func validateAnchors(anchorPatterns []anchor, pattern interface{}, path string) (string, error) {
-	switch typedPattern := pattern.(type) {
+func validateClone(c kyverno.CloneFrom) (string, error) {
+	if c.Name == "" {
+		return "name", fmt.Errorf("name cannot be empty")
+	}
+	if c.Namespace == "" {
+		return "namespace", fmt.Errorf("namespace cannot be empty")
+	}
+	return "", nil
+}
+
+func validatePattern(patternElement interface{}, path string, supportedAnchors []anchor.IsAnchor) (string, error) {
+	switch typedPatternElement := patternElement.(type) {
 	case map[string]interface{}:
-		return validateAnchorsOnMap(anchorPatterns, typedPattern, path)
+		return validateMap(typedPatternElement, path, supportedAnchors)
 	case []interface{}:
-		return validateAnchorsOnArray(anchorPatterns, typedPattern, path)
+		return validateArray(typedPatternElement, path, supportedAnchors)
 	case string, float64, int, int64, bool, nil:
-		// check on type string
-		if checkedPattern := reflect.ValueOf(pattern); checkedPattern.Kind() == reflect.String {
-			if hasAnchor, str := hasExistingAnchor(checkedPattern.String()); hasAnchor {
-				return path, fmt.Errorf("existing anchor at %s must be of type array, found: %v", path+str, checkedPattern.Kind())
-			}
-		}
-		// return nil on all other cases
-		return "", nil
-	case interface{}:
-		// special case for generate clone, as it is a struct
-		if clone, ok := pattern.(kyverno.CloneFrom); ok {
-			return "", validateAnchorsOnCloneFrom(nil, clone)
-		}
+		//TODO? check operator
 		return "", nil
 	default:
-		glog.V(4).Infof("Pattern contains unknown type %T. Path: %s", pattern, path)
-		return path, fmt.Errorf("pattern contains unknown type, path: %s", path)
+		return path, fmt.Errorf("Validation rule failed at '%s', pattern contains unknown type", path)
 	}
+	return "", nil
 }
 
-func validateAnchorsOnCloneFrom(anchorPatterns []anchor, pattern kyverno.CloneFrom) error {
-	// namespace and name are required fields
-	// if wrapped with invalid character, this field is empty during unmarshaling
-	if pattern.Namespace == "" {
-		return errors.New("namespace is requried")
-	}
-
-	if pattern.Name == "" {
-		return errors.New("name is requried")
-	}
-
-	return nil
-}
-
-func validateAnchorsOnMap(anchorPatterns []anchor, pattern map[string]interface{}, path string) (string, error) {
-	for key, patternElement := range pattern {
-		if valid, str := hasValidAnchors(anchorPatterns, key); !valid {
-			return path, fmt.Errorf("invalid anchor found at %s, expect: %s", path+str, joinAnchors(anchorPatterns))
+func validateMap(patternMap map[string]interface{}, path string, supportedAnchors []anchor.IsAnchor) (string, error) {
+	// check if anchors are defined
+	for key, value := range patternMap {
+		// if key is anchor
+		// check regex () -> this is anchor
+		// ()
+		// single char ()
+		matched, err := regexp.MatchString(`^.?\(.+\)$`, key)
+		if err != nil {
+			return path + "/" + key, fmt.Errorf("Unable to parse the field %s: %v", key, err)
 		}
-		if hasAnchor, str := hasExistingAnchor(key); hasAnchor {
-			if checkedPattern := reflect.ValueOf(patternElement); checkedPattern.Kind() != reflect.Slice {
-				return path, fmt.Errorf("existing anchor at %s must be of type array, found: %T", path+str, patternElement)
+		// check the type of anchor
+		if matched {
+			// some type of anchor
+			// check if valid anchor
+			if !checkAnchors(key, supportedAnchors) {
+				return path + "/" + key, fmt.Errorf("Unsupported anchor %s", key)
+			}
+
+			// addition check for existance anchor
+			// value must be of type list
+			if anchor.IsExistanceAnchor(key) {
+				typedValue, ok := value.([]interface{})
+				if !ok {
+					return path + "/" + key, fmt.Errorf("Existance anchor should have value of type list")
+				}
+				// validate there is only one entry in the list
+				if len(typedValue) == 0 || len(typedValue) > 1 {
+					return path + "/" + key, fmt.Errorf("Existance anchor: single value expected, multiple specified")
+				}
 			}
 		}
-
-		if path, err := validateAnchors(anchorPatterns, patternElement, path+key+"/"); err != nil {
-			return path, err
+		// lets validate the values now :)
+		if errPath, err := validatePattern(value, path+"/"+key, supportedAnchors); err != nil {
+			return errPath, err
 		}
 	}
-
 	return "", nil
 }
 
-func validateAnchorsOnArray(anchorPatterns []anchor, patternArray []interface{}, path string) (string, error) {
-	if len(patternArray) == 0 {
-		return path, fmt.Errorf("pattern array at %s is empty", path)
-	}
-
-	for i, pattern := range patternArray {
+func validateArray(patternArray []interface{}, path string, supportedAnchors []anchor.IsAnchor) (string, error) {
+	for i, patternElement := range patternArray {
 		currentPath := path + strconv.Itoa(i) + "/"
-		if path, err := validateAnchors(anchorPatterns, pattern, currentPath); err != nil {
-			return path, err
+		// lets validate the values now :)
+		if errPath, err := validatePattern(patternElement, currentPath, supportedAnchors); err != nil {
+			return errPath, err
 		}
 	}
-
 	return "", nil
 }
+
+func checkAnchors(key string, supportedAnchors []anchor.IsAnchor) bool {
+	for _, f := range supportedAnchors {
+		if f(key) {
+			return true
+		}
+	}
+	return false
+}

pkg/engine/utils.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/minio/minio/pkg/wildcard"
 	kyverno "github.com/nirmata/kyverno/pkg/api/kyverno/v1alpha1"
+	"github.com/nirmata/kyverno/pkg/engine/anchor"
 	"github.com/nirmata/kyverno/pkg/utils"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 
@@ -209,11 +210,12 @@ func ParseNamespaceFromObject(bytes []byte) string {
 	return ""
 }
 
+// Validation
 func getAnchorsFromMap(anchorsMap map[string]interface{}) map[string]interface{} {
 	result := make(map[string]interface{})
 
 	for key, value := range anchorsMap {
-		if isConditionAnchor(key) || isExistanceAnchor(key) {
+		if anchor.IsConditionAnchor(key) || anchor.IsExistanceAnchor(key) {
 			result[key] = value
 		}
 	}
@@ -221,13 +223,14 @@ func getAnchorsFromMap(anchorsMap map[string]interface{}) map[string]interface{}
 	return result
 }
 
+// Mutation
 func getElementsFromMap(anchorsMap map[string]interface{}) (map[string]interface{}, map[string]interface{}) {
 	anchors := make(map[string]interface{})
 	elementsWithoutanchor := make(map[string]interface{})
 	for key, value := range anchorsMap {
-		if isConditionAnchor(key) || isExistanceAnchor(key) {
+		if anchor.IsConditionAnchor(key) || anchor.IsExistanceAnchor(key) {
 			anchors[key] = value
-		} else if !isAddingAnchor(key) {
+		} else if !anchor.IsAddingAnchor(key) {
 			elementsWithoutanchor[key] = value
 		}
 	}
@@ -237,7 +240,7 @@ func getElementsFromMap(anchorsMap map[string]interface{}) (map[string]interface
 
 func getAnchorFromMap(anchorsMap map[string]interface{}) (string, interface{}) {
 	for key, value := range anchorsMap {
-		if isConditionAnchor(key) || isExistanceAnchor(key) {
+		if anchor.IsConditionAnchor(key) || anchor.IsExistanceAnchor(key) {
 			return key, value
 		}
 	}
@@ -254,13 +257,13 @@ func findKind(kinds []string, kindGVK string) bool {
 	return false
 }
 
-func isConditionAnchor(str string) bool {
-	if len(str) < 2 {
-		return false
-	}
+// func isConditionAnchor(str string) bool {
+// 	if len(str) < 2 {
+// 		return false
+// 	}
 
-	return (str[0] == '(' && str[len(str)-1] == ')')
-}
+// 	return (str[0] == '(' && str[len(str)-1] == ')')
+// }
 
 func getRawKeyIfWrappedWithAttributes(str string) string {
 	if len(str) < 2 {
@@ -284,48 +287,6 @@ func isStringIsReference(str string) bool {
 	return str[0] == '$' && str[1] == '(' && str[len(str)-1] == ')'
 }
 
-func isExistanceAnchor(str string) bool {
-	left := "^("
-	right := ")"
-
-	if len(str) < len(left)+len(right) {
-		return false
-	}
-
-	return (str[:len(left)] == left && str[len(str)-len(right):] == right)
-}
-
-func isEqualityAnchor(str string) bool {
-	left := "=("
-	right := ")"
-	if len(str) < len(left)+len(right) {
-		return false
-	}
-	//TODO: trim spaces ?
-	return (str[:len(left)] == left && str[len(str)-len(right):] == right)
-}
-
-func isNegationAnchor(str string) bool {
-	left := "X("
-	right := ")"
-	if len(str) < len(left)+len(right) {
-		return false
-	}
-	//TODO: trim spaces ?
-	return (str[:len(left)] == left && str[len(str)-len(right):] == right)
-}
-
-func isAddingAnchor(key string) bool {
-	const left = "+("
-	const right = ")"
-
-	if len(key) < len(left)+len(right) {
-		return false
-	}
-
-	return left == key[:len(left)] && right == key[len(key)-len(right):]
-}
-
 // Checks if array object matches anchors. If not - skip - return true
 func skipArrayObject(object, anchors map[string]interface{}) bool {
 	for key, pattern := range anchors {
@@ -346,11 +307,11 @@ func skipArrayObject(object, anchors map[string]interface{}) bool {
 
 // removeAnchor remove special characters around anchored key
 func removeAnchor(key string) string {
-	if isConditionAnchor(key) {
+	if anchor.IsConditionAnchor(key) {
 		return key[1 : len(key)-1]
 	}
 
-	if isExistanceAnchor(key) || isAddingAnchor(key) || isEqualityAnchor(key) || isNegationAnchor(key) {
+	if anchor.IsExistanceAnchor(key) || anchor.IsAddingAnchor(key) || anchor.IsEqualityAnchor(key) || anchor.IsNegationAnchor(key) {
 		return key[2 : len(key)-1]
 	}
 

pkg/engine/utils_test.go

@@ -392,57 +392,6 @@ func TestResourceDescriptionExclude_Label_Expression_Match(t *testing.T) {
 	assert.Assert(t, !MatchesResourceDescription(*resource, rule))
 }
 
-func TestWrappedWithParentheses_StringIsWrappedWithParentheses(t *testing.T) {
-	str := "(something)"
-	assert.Assert(t, isConditionAnchor(str))
-}
-
-func TestWrappedWithParentheses_StringHasOnlyParentheses(t *testing.T) {
-	str := "()"
-	assert.Assert(t, isConditionAnchor(str))
-}
-
-func TestWrappedWithParentheses_StringHasNoParentheses(t *testing.T) {
-	str := "something"
-	assert.Assert(t, !isConditionAnchor(str))
-}
-
-func TestWrappedWithParentheses_StringHasLeftParentheses(t *testing.T) {
-	str := "(something"
-	assert.Assert(t, !isConditionAnchor(str))
-}
-
-func TestWrappedWithParentheses_StringHasRightParentheses(t *testing.T) {
-	str := "something)"
-	assert.Assert(t, !isConditionAnchor(str))
-}
-
-func TestWrappedWithParentheses_StringParenthesesInside(t *testing.T) {
-	str := "so)m(et(hin)g"
-	assert.Assert(t, !isConditionAnchor(str))
-}
-
-func TestWrappedWithParentheses_Empty(t *testing.T) {
-	str := ""
-	assert.Assert(t, !isConditionAnchor(str))
-}
-
-func TestIsExistanceAnchor_Yes(t *testing.T) {
-	assert.Assert(t, isExistanceAnchor("^(abc)"))
-}
-
-func TestIsExistanceAnchor_NoRightBracket(t *testing.T) {
-	assert.Assert(t, !isExistanceAnchor("^(abc"))
-}
-
-func TestIsExistanceAnchor_OnlyHat(t *testing.T) {
-	assert.Assert(t, !isExistanceAnchor("^abc"))
-}
-
-func TestIsExistanceAnchor_ConditionAnchor(t *testing.T) {
-	assert.Assert(t, !isExistanceAnchor("(abc)"))
-}
-
 func TestRemoveAnchor_ConditionAnchor(t *testing.T) {
 	assert.Equal(t, removeAnchor("(abc)"), "abc")
 }

pkg/engine/validation.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/golang/glog"
 	kyverno "github.com/nirmata/kyverno/pkg/api/kyverno/v1alpha1"
+	"github.com/nirmata/kyverno/pkg/engine/anchor"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 )
 
@@ -41,10 +42,9 @@ func Validate(policy kyverno.ClusterPolicy, resource unstructured.Unstructured)
 	}
 
 	for _, rule := range policy.Spec.Rules {
-		if reflect.DeepEqual(rule.Validation, kyverno.Validation{}) {
+		if !rule.HasValidate() {
 			continue
 		}
-
 		// check if the resource satisfies the filter conditions defined in the rule
 		// TODO: this needs to be extracted, to filter the resource so that we can avoid passing resources that
 		// dont statisfy a policy rule resource description
@@ -201,7 +201,7 @@ func validateMap(resourceMap, patternMap map[string]interface{}, origPattern int
 		// but if there are non then its a if then check
 		if err != nil {
 			// If Conditional anchor fails then we dont process the resources
-			if isConditionAnchor(key) {
+			if anchor.IsConditionAnchor(key) {
 				glog.V(4).Infof("condition anchor did not satisfy, wont process the resources: %s", err)
 				return "", nil
 			}