refactor capabilities to a singleton struct

pkg/capabilities/capabilities_test.go

@@ -0,0 +1,50 @@
+/*
+Copyright 2014 The Kubernetes Authors.
+
+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 capabilities
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestGet(t *testing.T) {
+	defaultCap := Capabilities{
+		AllowPrivileged: false,
+		PrivilegedSources: PrivilegedSources{
+			HostNetworkSources: []string{},
+			HostPIDSources:     []string{},
+			HostIPCSources:     []string{},
+		},
+	}
+
+	res := Get()
+	if !reflect.DeepEqual(defaultCap, res) {
+		t.Fatalf("expected Capabilities: %#v, got a non-default: %#v", defaultCap, res)
+	}
+
+	cap := Capabilities{
+		PrivilegedSources: PrivilegedSources{
+			HostNetworkSources: []string{"A", "B"},
+		},
+	}
+	SetForTests(cap)
+
+	res = Get()
+	if !reflect.DeepEqual(cap, res) {
+		t.Fatalf("expected Capabilities: %#v , got a different: %#v", cap, res)
+	}
+}