add test case for compatibility.go

container/libcontainer/compatibility_test.go

@@ -0,0 +1,56 @@
+// Copyright 2015 Google Inc. 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 libcontainer
+
+import (
+	"path/filepath"
+	"testing"
+)
+
+func TestReadConfig(t *testing.T) {
+	var (
+		testdata    string = "testdata"
+		containerID string = "1"
+	)
+	// Test with using the new config of docker v1.9.0
+	dockerRoot := filepath.Join(testdata, "docker-v1.9.1")
+	dockerRun := filepath.Join(testdata, "docker-v1.9.1")
+	config, err := ReadConfig(dockerRoot, dockerRun, containerID)
+	if err != nil {
+		t.Error(err)
+	}
+	if config.Hostname != containerID {
+		t.Errorf("Expected container hostname is %s, but got %s", containerID, config.Hostname)
+	}
+
+	// Test with using the pre config of docker v1.8.3
+	dockerRoot = filepath.Join(testdata, "docker-v1.8.3")
+	dockerRun = filepath.Join(testdata, "docker-v1.8.3")
+	config, err = ReadConfig(dockerRoot, dockerRun, containerID)
+	if err != nil {
+		t.Error(err)
+	}
+	if config.Hostname != containerID {
+		t.Errorf("Expected container hostname is %s, but got %s", containerID, config.Hostname)
+	}
+
+	// Test with using non-existed old config, return an error
+	dockerRoot = filepath.Join(testdata, "docker-v1.8.0")
+	dockerRun = filepath.Join(testdata, "docker-v1.8.0")
+	config, err = ReadConfig(dockerRoot, dockerRun, containerID)
+	if err == nil {
+		t.Error("Expected an error, but got nil")
+	}
+}