diff --git a/src/configuration.cc b/src/configuration.cc
index ca97668a..796b6020 100644
--- a/src/configuration.cc
+++ b/src/configuration.cc
@@ -19,6 +19,7 @@
 #include <boost/program_options.hpp>
 #include <iostream>
 #include <map>
+#include <fstream>
 
 #include <yaml-cpp/yaml.h>
 
@@ -132,10 +133,15 @@ int MetadataAgentConfiguration::ParseArguments(int ac, char** av) {
 }
 
 void MetadataAgentConfiguration::ParseConfigFile(const std::string& filename) {
-  std::lock_guard<std::mutex> lock(mutex_);
   if (filename.empty()) return;
 
-  YAML::Node config = YAML::LoadFile(filename);
+  std::ifstream input(filename);
+  ParseConfiguration(input);
+}
+
+void MetadataAgentConfiguration::ParseConfiguration(std::istream& input) {
+  YAML::Node config = YAML::Load(input);
+  std::lock_guard<std::mutex> lock(mutex_);
   project_id_ =
       config["ProjectId"].as<std::string>(kDefaultProjectId);
   credentials_file_ =
diff --git a/src/configuration.h b/src/configuration.h
index 4cd91f52..cc4dbb94 100644
--- a/src/configuration.h
+++ b/src/configuration.h
@@ -139,7 +139,10 @@ class MetadataAgentConfiguration {
   }
 
  private:
+  friend class MetadataAgentConfigurationTest;
+
   void ParseConfigFile(const std::string& filename);
+  void ParseConfiguration(std::istream& input);
 
   mutable std::mutex mutex_;
   std::string project_id_;
diff --git a/test/Makefile b/test/Makefile
index efea1665..84460837 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -9,10 +9,14 @@ GTEST_SRCS_=$(GTEST_SOURCEDIR)/*.cc $(GTEST_SOURCEDIR)/*.h $(GTEST_HEADERS)
 # TODO: Factor out the common variables.
 CPP_NETLIB_DIR=$(LIBDIR)/cpp-netlib
 YAML_CPP_DIR=$(LIBDIR)/yaml-cpp
+YAML_CPP_LIBDIR=$(YAML_CPP_DIR)
 
-CPPFLAGS+=-isystem $(GTEST_DIR)/include
+YAML_CPP_LIBS=$(YAML_CPP_LIBDIR)/libyaml-cpp.a
+
+CPPFLAGS+=-isystem $(GTEST_DIR)/include -I$(YAML_CPP_DIR)/include
 CXXFLAGS=-std=c++11 -g -pthread
-LDLIBS=-lpthread
+LDLIBS=-lpthread -lboost_program_options -lyaml-cpp
+LDFLAGS=-L$(YAML_CPP_LIBDIR)
 
 # Where to find code under test.
 SRC_DIR=../src
@@ -22,6 +26,7 @@ TEST_SOURCES=$(wildcard $(TEST_DIR)/*_unittest.cc)
 TEST_OBJS=$(TEST_SOURCES:$(TEST_DIR)/%.cc=%.o)
 TESTS=\
       base64_unittest \
+      configuration_unittest \
       format_unittest \
       time_unittest
 
@@ -48,6 +53,9 @@ init-submodules:
 	git submodule update --init $(GTEST_MODULE)
 	touch init-submodules
 
+$(YAML_CPP_LIBS):
+	cd $(SRC_DIR) && $(MAKE) $@
+
 $(SRC_DIR)/%.o: $(SRC_DIR)/%.cc
 	cd $(SRC_DIR) && $(MAKE) $(@:$(SRC_DIR)/%=%)
 
@@ -66,7 +74,8 @@ format_unittest: $(GTEST_LIB) format_unittest.o $(SRC_DIR)/format.o
 	$(CXX) $(LDFLAGS) $^ $(LDLIBS) -o $@
 base64_unittest: $(GTEST_LIB) base64_unittest.o $(SRC_DIR)/base64.o
 	$(CXX) $(LDFLAGS) $^ $(LDLIBS) -o $@
-
+configuration_unittest: $(GTEST_LIB) $(YAML_CPP_LIBS) configuration_unittest.o $(SRC_DIR)/configuration.o
+	$(CXX) $(LDFLAGS) $^ $(LDLIBS) -o $@
 time_unittest: $(GTEST_LIB) time_unittest.o $(SRC_DIR)/time.o
 	$(CXX) $(LDFLAGS) $^ $(LDLIBS) -o $@
 
diff --git a/test/configuration_unittest.cc b/test/configuration_unittest.cc
new file mode 100644
index 00000000..3432abdf
--- /dev/null
+++ b/test/configuration_unittest.cc
@@ -0,0 +1,88 @@
+#include "../src/configuration.h"
+#include "gtest/gtest.h"
+
+namespace google {
+
+class MetadataAgentConfigurationTest : public ::testing::Test {
+ protected:
+  void ParseConfiguration(const std::string& input) {
+    std::stringstream stream(input);
+    config.ParseConfiguration(stream);
+  }
+
+  void VerifyDefaultConfig() const {
+    EXPECT_EQ("", config.ProjectId());
+    EXPECT_EQ("", config.CredentialsFile());
+    EXPECT_EQ(3, config.MetadataApiNumThreads());
+    EXPECT_EQ(8000, config.MetadataApiPort());
+    EXPECT_EQ(".", config.MetadataApiResourceTypeSeparator());
+    EXPECT_EQ(60, config.MetadataReporterIntervalSeconds());
+    EXPECT_EQ(false, config.MetadataReporterPurgeDeleted());
+    EXPECT_EQ("https://stackdriver.googleapis.com/"
+              "v1beta2/projects/{{project_id}}/resourceMetadata:batchUpdate",
+              config.MetadataIngestionEndpointFormat());
+    EXPECT_EQ(8*1024*1024, config.MetadataIngestionRequestSizeLimitBytes());
+    EXPECT_EQ("0.1", config.MetadataIngestionRawContentVersion());
+    EXPECT_EQ(60*60, config.InstanceUpdaterIntervalSeconds());
+    EXPECT_EQ("", config.InstanceResourceType());
+    EXPECT_EQ(60, config.DockerUpdaterIntervalSeconds());
+    EXPECT_EQ("unix://%2Fvar%2Frun%2Fdocker.sock/",
+              config.DockerEndpointHost());
+    EXPECT_EQ("1.23", config.DockerApiVersion());
+    EXPECT_EQ("limit=30", config.DockerContainerFilter());
+    EXPECT_EQ(0, config.KubernetesUpdaterIntervalSeconds());
+    EXPECT_EQ("https://kubernetes.default.svc",
+              config.KubernetesEndpointHost());
+    EXPECT_EQ("", config.KubernetesPodLabelSelector());
+    EXPECT_EQ("", config.KubernetesClusterName());
+    EXPECT_EQ("", config.KubernetesClusterLocation());
+    EXPECT_EQ("", config.KubernetesNodeName());
+    EXPECT_EQ(true, config.KubernetesUseWatch());
+    EXPECT_EQ("", config.InstanceId());
+    EXPECT_EQ("", config.InstanceZone());
+  }
+
+  MetadataAgentConfiguration config;
+};
+
+TEST_F(MetadataAgentConfigurationTest, NoConfig) {
+  VerifyDefaultConfig();
+}
+
+TEST_F(MetadataAgentConfigurationTest, EmptyConfig) {
+  ParseConfiguration("");
+  VerifyDefaultConfig();
+}
+
+TEST_F(MetadataAgentConfigurationTest, PopulatedConfig) {
+  ParseConfiguration(
+      "ProjectId: TestProjectId\n"
+      "MetadataApiNumThreads: 13\n"
+      "MetadataReporterPurgeDeleted: true"
+  );
+  EXPECT_EQ("TestProjectId", config.ProjectId());
+  EXPECT_EQ(13, config.MetadataApiNumThreads());
+  EXPECT_EQ(true, config.MetadataReporterPurgeDeleted());
+}
+
+TEST_F(MetadataAgentConfigurationTest, CommentSkipped) {
+  ParseConfiguration(
+      "ProjectId: TestProjectId\n"
+      "#MetadataApiNumThreads: 13\n"
+      "MetadataReporterPurgeDeleted: true"
+  );
+  EXPECT_EQ(3, config.MetadataApiNumThreads());
+}
+
+TEST_F(MetadataAgentConfigurationTest, BlankLine) {
+  ParseConfiguration(
+      "ProjectId: TestProjectId\n"
+      "\n"
+      "\n"
+      "MetadataReporterPurgeDeleted: true"
+  );
+  EXPECT_EQ("TestProjectId", config.ProjectId());
+  EXPECT_EQ(true, config.MetadataReporterPurgeDeleted());
+}
+
+}  // namespace google