Add operation checking to admission control handlers

Adds a new method to the handler interface that returns true only if the
admission control handler handles that operation.

pkg/admission/chain_test.go

@@ -0,0 +1,152 @@
+/*
+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 admission
+
+import (
+	"fmt"
+	"testing"
+)
+
+type FakeHandler struct {
+	*Handler
+	name        string
+	admit       bool
+	admitCalled bool
+}
+
+func (h *FakeHandler) Admit(a Attributes) (err error) {
+	h.admitCalled = true
+	if h.admit {
+		return nil
+	}
+	return fmt.Errorf("Don't admit")
+}
+
+func makeHandler(name string, admit bool, ops ...Operation) Interface {
+	return &FakeHandler{
+		name:    name,
+		admit:   admit,
+		Handler: NewHandler(ops...),
+	}
+}
+
+func TestAdmit(t *testing.T) {
+	tests := []struct {
+		name      string
+		operation Operation
+		chain     chainAdmissionHandler
+		accept    bool
+		calls     map[string]bool
+	}{
+		{
+			name:      "all accept",
+			operation: Create,
+			chain: []Interface{
+				makeHandler("a", true, Update, Delete, Create),
+				makeHandler("b", true, Delete, Create),
+				makeHandler("c", true, Create),
+			},
+			calls:  map[string]bool{"a": true, "b": true, "c": true},
+			accept: true,
+		},
+		{
+			name:      "ignore handler",
+			operation: Create,
+			chain: []Interface{
+				makeHandler("a", true, Update, Delete, Create),
+				makeHandler("b", false, Delete),
+				makeHandler("c", true, Create),
+			},
+			calls:  map[string]bool{"a": true, "c": true},
+			accept: true,
+		},
+		{
+			name:      "ignore all",
+			operation: Connect,
+			chain: []Interface{
+				makeHandler("a", true, Update, Delete, Create),
+				makeHandler("b", false, Delete),
+				makeHandler("c", true, Create),
+			},
+			calls:  map[string]bool{},
+			accept: true,
+		},
+		{
+			name:      "reject one",
+			operation: Delete,
+			chain: []Interface{
+				makeHandler("a", true, Update, Delete, Create),
+				makeHandler("b", false, Delete),
+				makeHandler("c", true, Create),
+			},
+			calls:  map[string]bool{"a": true, "b": true},
+			accept: false,
+		},
+	}
+	for _, test := range tests {
+		err := test.chain.Admit(NewAttributesRecord(nil, "", "", "", test.operation, nil))
+		accepted := (err == nil)
+		if accepted != test.accept {
+			t.Errorf("%s: unexpected result of admit call: %v\n", test.name, accepted)
+		}
+		for _, h := range test.chain {
+			fake := h.(*FakeHandler)
+			_, shouldBeCalled := test.calls[fake.name]
+			if shouldBeCalled != fake.admitCalled {
+				t.Errorf("%s: handler %s not called as expected: %v", test.name, fake.name, fake.admitCalled)
+				continue
+			}
+		}
+	}
+}
+
+func TestHandles(t *testing.T) {
+	chain := chainAdmissionHandler{
+		makeHandler("a", true, Update, Delete, Create),
+		makeHandler("b", true, Delete, Create),
+		makeHandler("c", true, Create),
+	}
+
+	tests := []struct {
+		name      string
+		operation Operation
+		chain     chainAdmissionHandler
+		expected  bool
+	}{
+		{
+			name:      "all handle",
+			operation: Create,
+			expected:  true,
+		},
+		{
+			name:      "none handle",
+			operation: Connect,
+			expected:  false,
+		},
+		{
+			name:      "some handle",
+			operation: Delete,
+			expected:  true,
+		},
+	}
+	for _, test := range tests {
+		handles := chain.Handles(test.operation)
+		if handles != test.expected {
+			t.Errorf("Unexpected handles result. Expected: %v. Actual: %v", test.expected, handles)
+		}
+	}
+}