plumb PodSelector through the api

pkg/apis/extensions/helpers.go

+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package extensions
+
+import (
+	"fmt"
+
+	"sort"
+
+	"k8s.io/kubernetes/pkg/labels"
+	"k8s.io/kubernetes/pkg/util/sets"
+)
+
+// PodSelectorAsSelector converts the PodSelector api type into a struct that implements
+// labels.Selector
+func PodSelectorAsSelector(ps *PodSelector) (labels.Selector, error) {
+	if ps == nil {
+		return labels.Nothing(), nil
+	}
+	if len(ps.MatchLabels)+len(ps.MatchExpressions) == 0 {
+		return labels.Everything(), nil
+	}
+	selector := labels.LabelSelector{}
+	for k, v := range ps.MatchLabels {
+		req, err := labels.NewRequirement(k, labels.InOperator, sets.NewString(v))
+		if err != nil {
+			return nil, err
+		}
+		selector = append(selector, *req)
+	}
+	for _, expr := range ps.MatchExpressions {
+		var op labels.Operator
+		switch expr.Operator {
+		case PodSelectorOpIn:
+			op = labels.InOperator
+		case PodSelectorOpNotIn:
+			op = labels.NotInOperator
+		case PodSelectorOpExists:
+			op = labels.ExistsOperator
+		case PodSelectorOpDoesNotExist:
+			op = labels.DoesNotExistOperator
+		default:
+			return nil, fmt.Errorf("%q is not a valid pod selector operator", expr.Operator)
+		}
+		req, err := labels.NewRequirement(expr.Key, op, sets.NewString(expr.Values...))
+		if err != nil {
+			return nil, err
+		}
+		selector = append(selector, *req)
+	}
+	sort.Sort(labels.ByKey(selector))
+	return selector, nil
+}

pkg/apis/extensions/helpers_test.go

+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package extensions
+
+import (
+	"reflect"
+	"testing"
+
+	"k8s.io/kubernetes/pkg/labels"
+)
+
+func TestPodSelectorAsSelector(t *testing.T) {
+	matchLabels := map[string]string{"foo": "bar"}
+	matchExpressions := []PodSelectorRequirement{{
+		Key:      "baz",
+		Operator: PodSelectorOpIn,
+		Values:   []string{"qux", "norf"},
+	}}
+	mustParse := func(s string) labels.Selector {
+		out, e := labels.Parse(s)
+		if e != nil {
+			panic(e)
+		}
+		return out
+	}
+	tc := []struct {
+		in        *PodSelector
+		out       labels.Selector
+		expectErr bool
+	}{
+		{in: nil, out: labels.Nothing()},
+		{in: &PodSelector{}, out: labels.Everything()},
+		{
+			in:  &PodSelector{MatchLabels: matchLabels},
+			out: mustParse("foo in (bar)"),
+		},
+		{
+			in:  &PodSelector{MatchExpressions: matchExpressions},
+			out: mustParse("baz in (norf,qux)"),
+		},
+		{
+			in:  &PodSelector{MatchLabels: matchLabels, MatchExpressions: matchExpressions},
+			out: mustParse("foo in (bar),baz in (norf,qux)"),
+		},
+		{
+			in: &PodSelector{
+				MatchExpressions: []PodSelectorRequirement{{
+					Key:      "baz",
+					Operator: PodSelectorOpExists,
+					Values:   []string{"qux", "norf"},
+				}},
+			},
+			expectErr: true,
+		},
+	}
+
+	for i, tc := range tc {
+		out, err := PodSelectorAsSelector(tc.in)
+		if err == nil && tc.expectErr {
+			t.Errorf("[%v]expected error but got none.", i)
+		}
+		if err != nil && !tc.expectErr {
+			t.Errorf("[%v]did not expect error but got: %v", i, err)
+		}
+		if !reflect.DeepEqual(out, tc.out) {
+			t.Errorf("[%v]expected:\n\t%+v\nbut got:\n\t%+v", i, tc.out, out)
+		}
+	}
+}

pkg/apis/extensions/types.go

@@ -405,7 +405,7 @@ type JobSpec struct {
 	Completions *int `json:"completions,omitempty"`
 
 	// Selector is a label query over pods that should match the pod count.
-	Selector map[string]string `json:"selector"`
+	Selector *PodSelector `json:"selector,omitempty"`
 
 	// Template is the object that describes the pod that will be created when
 	// executing a job.
@@ -661,7 +661,7 @@ type PodSelector struct {
 	MatchExpressions []PodSelectorRequirement `json:"matchExpressions,omitempty"`
 }
 
-// A pod selector requirement is a selector that contains values, a key and an operator that
+// A pod selector requirement is a selector that contains values, a key, and an operator that
 // relates the key and values.
 type PodSelectorRequirement struct {
 	// key is the label key that the selector applies to.
@@ -669,10 +669,11 @@ type PodSelectorRequirement struct {
 	// operator represents a key's relationship to a set of values.
 	// Valid operators ard In, NotIn, Exists and DoesNotExist.
 	Operator PodSelectorOperator `json:"operator"`
-	// values is a set of string values. If the operator is In or NotIn,
-	// the values set must be non-empty. This array is replaced during a
-	// strategic merge patch.
-	Values []string `json:"stringValues,omitempty"`
+	// values is an array of string values. If the operator is In or NotIn,
+	// the values array must be non-empty. If the operator is Exists or DoesNotExist,
+	// the values array must be empty. This array is replaced during a strategic
+	// merge patch.
+	Values []string `json:"values,omitempty"`
 }
 
 // A pod selector operator is the set of operators that can be used in a selector requirement.

pkg/apis/extensions/v1beta1/defaults.go

@@ -92,8 +92,10 @@ func addDefaultingFuncs() {
 			labels := obj.Spec.Template.Labels
 			// TODO: support templates defined elsewhere when we support them in the API
 			if labels != nil {
-				if len(obj.Spec.Selector) == 0 {
-					obj.Spec.Selector = labels
+				if obj.Spec.Selector == nil {
+					obj.Spec.Selector = &PodSelector{
+						MatchLabels: labels,
+					}
 				}
 				if len(obj.Labels) == 0 {
 					obj.Labels = labels

pkg/apis/extensions/v1beta1/defaults_test.go

@@ -192,7 +192,9 @@ func TestSetDefaultDeployment(t *testing.T) {
 func TestSetDefaultJob(t *testing.T) {
 	expected := &Job{
 		Spec: JobSpec{
-			Selector:    map[string]string{"job": "selector"},
+			Selector: &PodSelector{
+				MatchLabels: map[string]string{"job": "selector"},
+			},
 			Completions: newInt(1),
 			Parallelism: newInt(1),
 		},
@@ -201,7 +203,9 @@ func TestSetDefaultJob(t *testing.T) {
 		// selector set explicitly, completions and parallelism - default
 		{
 			Spec: JobSpec{
-				Selector: map[string]string{"job": "selector"},
+				Selector: &PodSelector{
+					MatchLabels: map[string]string{"job": "selector"},
+				},
 			},
 		},
 		// selector from template labels, completions and parallelism - default

pkg/apis/extensions/v1beta1/types.go

@@ -412,7 +412,7 @@ type JobSpec struct {
 
 	// Selector is a label query over pods that should match the pod count.
 	// More info: http://releases.k8s.io/HEAD/docs/user-guide/labels.md#label-selectors
-	Selector map[string]string `json:"selector,omitempty"`
+	Selector *PodSelector `json:"selector,omitempty"`
 
 	// Template is the object that describes the pod that will be created when
 	// executing a job.
@@ -657,3 +657,40 @@ type ClusterAutoscalerList struct {
 
 	Items []ClusterAutoscaler `json:"items"`
 }
+
+// A pod selector is a label query over a set of pods. The result of matchLabels and
+// matchExpressions are ANDed. An empty pod selector matches all objects. A null
+// pod selector matches no objects.
+type PodSelector struct {
+	// matchLabels is a map of {key,value} pairs. A single {key,value} in the matchLabels
+	// map is equivalent to an element of matchExpressions, whose key field is "key", the
+	// operator is "In", and the values array contains only "value". The requirements are ANDed.
+	MatchLabels map[string]string `json:"matchLabels,omitempty"`
+	// matchExpressions is a list of pod selector requirements. The requirements are ANDed.
+	MatchExpressions []PodSelectorRequirement `json:"matchExpressions,omitempty"`
+}
+
+// A pod selector requirement is a selector that contains values, a key, and an operator that
+// relates the key and values.
+type PodSelectorRequirement struct {
+	// key is the label key that the selector applies to.
+	Key string `json:"key" patchStrategy:"merge" patchMergeKey:"key"`
+	// operator represents a key's relationship to a set of values.
+	// Valid operators ard In, NotIn, Exists and DoesNotExist.
+	Operator PodSelectorOperator `json:"operator"`
+	// values is an array of string values. If the operator is In or NotIn,
+	// the values array must be non-empty. If the operator is Exists or DoesNotExist,
+	// the values array must be empty. This array is replaced during a strategic
+	// merge patch.
+	Values []string `json:"values,omitempty"`
+}
+
+// A pod selector operator is the set of operators that can be used in a selector requirement.
+type PodSelectorOperator string
+
+const (
+	PodSelectorOpIn           PodSelectorOperator = "In"
+	PodSelectorOpNotIn        PodSelectorOperator = "NotIn"
+	PodSelectorOpExists       PodSelectorOperator = "Exists"
+	PodSelectorOpDoesNotExist PodSelectorOperator = "DoesNotExist"
+)

pkg/apis/extensions/validation/validation.go

@@ -345,16 +345,19 @@ func ValidateJobSpec(spec *extensions.JobSpec) errs.ValidationErrorList {
 	if spec.Completions != nil && *spec.Completions < 0 {
 		allErrs = append(allErrs, errs.NewFieldInvalid("completions", spec.Completions, isNegativeErrorMsg))
 	}
-
-	selector := labels.Set(spec.Selector).AsSelector()
-	if selector.Empty() {
+	if spec.Selector == nil {
 		allErrs = append(allErrs, errs.NewFieldRequired("selector"))
+	} else {
+		allErrs = append(allErrs, ValidatePodSelector(spec.Selector).Prefix("selector")...)
 	}
 
-	labels := labels.Set(spec.Template.Labels)
-	if !selector.Matches(labels) {
-		allErrs = append(allErrs, errs.NewFieldInvalid("template.labels", spec.Template.Labels, "selector does not match template"))
+	if selector, err := extensions.PodSelectorAsSelector(spec.Selector); err == nil {
+		labels := labels.Set(spec.Template.Labels)
+		if !selector.Matches(labels) {
+			allErrs = append(allErrs, errs.NewFieldInvalid("template.metadata.labels", spec.Template.Labels, "selector does not match template"))
+		}
 	}
+
 	allErrs = append(allErrs, apivalidation.ValidatePodTemplateSpec(&spec.Template).Prefix("template")...)
 	if spec.Template.Spec.RestartPolicy != api.RestartPolicyOnFailure &&
 		spec.Template.Spec.RestartPolicy != api.RestartPolicyNever {
@@ -568,3 +571,33 @@ func ValidateClusterAutoscaler(autoscaler *extensions.ClusterAutoscaler) errs.Va
 	allErrs = append(allErrs, validateClusterAutoscalerSpec(autoscaler.Spec)...)
 	return allErrs
 }
+
+func ValidatePodSelector(ps *extensions.PodSelector) errs.ValidationErrorList {
+	allErrs := errs.ValidationErrorList{}
+	if ps == nil {
+		return allErrs
+	}
+	allErrs = append(allErrs, apivalidation.ValidateLabels(ps.MatchLabels, "matchLabels")...)
+	for i, expr := range ps.MatchExpressions {
+		allErrs = append(allErrs, ValidatePodSelectorRequirement(expr).Prefix(fmt.Sprintf("matchExpressions.[%v]", i))...)
+	}
+	return allErrs
+}
+
+func ValidatePodSelectorRequirement(sr extensions.PodSelectorRequirement) errs.ValidationErrorList {
+	allErrs := errs.ValidationErrorList{}
+	switch sr.Operator {
+	case extensions.PodSelectorOpIn, extensions.PodSelectorOpNotIn:
+		if len(sr.Values) == 0 {
+			allErrs = append(allErrs, errs.NewFieldInvalid("values", sr.Values, "must be non-empty when operator is In or NotIn"))
+		}
+	case extensions.PodSelectorOpExists, extensions.PodSelectorOpDoesNotExist:
+		if len(sr.Values) > 0 {
+			allErrs = append(allErrs, errs.NewFieldInvalid("values", sr.Values, "must be empty when operator is Exists or DoesNotExist"))
+		}
+	default:
+		allErrs = append(allErrs, errs.NewFieldInvalid("operator", sr.Operator, "not a valid pod selector operator"))
+	}
+	allErrs = append(allErrs, apivalidation.ValidateLabelName(sr.Key, "key")...)
+	return allErrs
+}

pkg/apis/extensions/validation/validation_test.go

@@ -192,7 +192,6 @@ func TestValidateDaemonSetStatusUpdate(t *testing.T) {
 			t.Errorf("expected failure: %s", testName)
 		}
 	}
-
 }
 
 func TestValidateDaemonSetUpdate(t *testing.T) {
@@ -725,10 +724,12 @@ func TestValidateDeployment(t *testing.T) {
 }
 
 func TestValidateJob(t *testing.T) {
-	validSelector := map[string]string{"a": "b"}
+	validSelector := &extensions.PodSelector{
+		MatchLabels: map[string]string{"a": "b"},
+	}
 	validPodTemplateSpec := api.PodTemplateSpec{
 		ObjectMeta: api.ObjectMeta{
-			Labels: validSelector,
+			Labels: validSelector.MatchLabels,
 		},
 		Spec: api.PodSpec{
 			RestartPolicy: api.RestartPolicyOnFailure,
@@ -783,11 +784,10 @@ func TestValidateJob(t *testing.T) {
 				Namespace: api.NamespaceDefault,
 			},
 			Spec: extensions.JobSpec{
-				Selector: map[string]string{},
 				Template: validPodTemplateSpec,
 			},
 		},
-		"spec.template.labels:selector does not match template": {
+		"spec.template.metadata.labels: invalid value 'map[y:z]', Details: selector does not match template": {
 			ObjectMeta: api.ObjectMeta{
 				Name:      "myjob",
 				Namespace: api.NamespaceDefault,
@@ -815,7 +815,7 @@ func TestValidateJob(t *testing.T) {
 				Selector: validSelector,
 				Template: api.PodTemplateSpec{
 					ObjectMeta: api.ObjectMeta{
-						Labels: validSelector,
+						Labels: validSelector.MatchLabels,
 					},
 					Spec: api.PodSpec{
 						RestartPolicy: api.RestartPolicyAlways,

pkg/labels/selector.go

@@ -47,6 +47,18 @@ func Everything() Selector {
 	return LabelSelector{}
 }
 
+type nothingSelector struct{}
+
+func (n nothingSelector) Matches(_ Labels) bool                         { return false }
+func (n nothingSelector) Empty() bool                                   { return false }
+func (n nothingSelector) String() string                                { return "<null>" }
+func (n nothingSelector) Add(_ string, _ Operator, _ []string) Selector { return n }
+
+// Nothing returns a selector that matches no labels
+func Nothing() Selector {
+	return nothingSelector{}
+}
+
 // Operator represents a key's relationship
 // to a set of values in a Requirement.
 type Operator string