apmanager: store config files under /var/run/apmanager

This prevents non-root/apmanager users from modifying the files generated
by apmanager.

Also add a wrapper class for base::WriteFile to prevent any file writes
during unittest.

BUG=chromium:446679
TEST=USE="asan clang" FEATURES=test emerge-$BOARD apmanager
     Start an AP service using apmanager, verify hostapd and dhcp server
     config files are store in "/var/run/apmanager/hostapd" and
     "/var/run/apmanager/dnsmasq" respectively.

Change-Id: I2bf2d34a8c95c9493f2cf5d5eb4895fefcdae8dc
Reviewed-on: https://chromium-review.googlesource.com/239632
Reviewed-by: Paul Stewart <pstew@chromium.org>
Commit-Queue: Zeping Qiu <zqiu@chromium.org>
Trybot-Ready: Zeping Qiu <zqiu@chromium.org>
Tested-by: Zeping Qiu <zqiu@chromium.org>

1 files changed, 38 insertions, 0 deletions

diff --git a/mock_file_writer.h b/mock_file_writer.h
new file mode 100644
index 0000000..f5a7f31
--- /dev/null
+++ b/mock_file_writer.h
@@ -0,0 +1,38 @@
+// Copyright 2015 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef APMANAGER_MOCK_FILE_WRITER_H_
+#define APMANAGER_MOCK_FILE_WRITER_H_
+
+#include <string>
+
+#include <base/lazy_instance.h>
+#include <gmock/gmock.h>
+
+#include "apmanager/file_writer.h"
+
+namespace apmanager {
+
+class MockFileWriter : public FileWriter {
+ public:
+  ~MockFileWriter() override;
+
+  // This is a singleton. Use MockFileWriter::GetInstance()->Foo().
+  static MockFileWriter* GetInstance();
+
+  MOCK_METHOD2(Write, bool(const std::string& file_name,
+                           const std::string& content));
+
+ protected:
+  MockFileWriter();
+
+ private:
+  friend struct base::DefaultLazyInstanceTraits<MockFileWriter>;
+
+  DISALLOW_COPY_AND_ASSIGN(MockFileWriter);
+};
+
+}  // namespace apmanager
+
+#endif  // APMANAGER_MOCK_FILE_WRITER_H_