Support for publicly accessible configuration parsing to support testing

src/configuration.cc

@@ -116,6 +116,11 @@ MetadataAgentConfiguration::MetadataAgentConfiguration()
       instance_zone_(kDefaultInstanceZone),
       health_check_file_(kDefaultHealthCheckFile) {}
 
+MetadataAgentConfiguration::MetadataAgentConfiguration(std::istream& input)
+    : MetadataAgentConfiguration() {
+  ParseConfiguration(input);
+}
+
 int MetadataAgentConfiguration::ParseArguments(int ac, char** av) {
   std::string config_file;
   boost::program_options::options_description flags_desc;

src/configuration.h

@@ -19,17 +19,17 @@
 #include <mutex>
 #include <string>
 
+int main(int, char**);
+
 namespace google {
 
 class MetadataAgentConfiguration {
  public:
   MetadataAgentConfiguration();
-  // Parse the command line.
-  // A zero return value means that parsing succeeded and the program should
-  // proceed.  A positive return value means that parsing failed.  A negative
-  // value means that parsing succeeded, but all of the arguments were handled
-  // within the function and the program should exit with a success exit code.
-  int ParseArguments(int ac, char** av);
+  MetadataAgentConfiguration(std::istream& input);
+  // Used to accept inline construction of streams.
+  MetadataAgentConfiguration(std::istream&& input)
+      : MetadataAgentConfiguration(input) {}
 
   // Shared configuration.
   const std::string& ProjectId() const {
@@ -157,11 +157,16 @@ class MetadataAgentConfiguration {
   }
 
  private:
-  friend class MetadataAgentConfigurationTest;
-  friend class HealthCheckerUnittest;
+  friend int ::main(int, char**);  // Calls ParseArguments.
 
   void ParseConfigFile(const std::string& filename);
   void ParseConfiguration(std::istream& input);
+  // Parse the command line.
+  // A zero return value means that parsing succeeded and the program should
+  // proceed.  A positive return value means that parsing failed.  A negative
+  // value means that parsing succeeded, but all of the arguments were handled
+  // within the function and the program should exit with a success exit code.
+  int ParseArguments(int ac, char** av);
 
   mutable std::mutex mutex_;
   std::string project_id_;

test/configuration_unittest.cc

@@ -4,91 +4,80 @@
 
 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_THAT(config.MetadataReporterUserAgent(),
-                ::testing::StartsWith("metadata-agent/"));
-    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());
-    EXPECT_EQ("/var/run/metadata-agent/health/unhealthy", config.HealthCheckFile());
-  }
+void VerifyDefaultConfig(const MetadataAgentConfiguration& config) {
+  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_THAT(config.MetadataReporterUserAgent(),
+              ::testing::StartsWith("metadata-agent/"));
+  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());
+  EXPECT_EQ("/var/run/metadata-agent/health/unhealthy", config.HealthCheckFile());
+}
 
+TEST(MetadataAgentConfigurationTest, NoConfig) {
   MetadataAgentConfiguration config;
-};
-
-TEST_F(MetadataAgentConfigurationTest, NoConfig) {
-  VerifyDefaultConfig();
+  VerifyDefaultConfig(config);
 }
 
-TEST_F(MetadataAgentConfigurationTest, EmptyConfig) {
-  ParseConfiguration("");
-  VerifyDefaultConfig();
+TEST(MetadataAgentConfigurationTest, EmptyConfig) {
+  MetadataAgentConfiguration config(std::istringstream(""));
+  VerifyDefaultConfig(config);
 }
 
-TEST_F(MetadataAgentConfigurationTest, PopulatedConfig) {
-  ParseConfiguration(
+TEST(MetadataAgentConfigurationTest, PopulatedConfig) {
+  MetadataAgentConfiguration config(std::istringstream(
       "ProjectId: TestProjectId\n"
       "MetadataApiNumThreads: 13\n"
       "MetadataReporterPurgeDeleted: true\n"
       "MetadataReporterUserAgent: \"foobar/foobaz\"\n"
       "HealthCheckFile: /a/b/c\n"
-  );
+  ));
   EXPECT_EQ("TestProjectId", config.ProjectId());
   EXPECT_EQ(13, config.MetadataApiNumThreads());
   EXPECT_EQ(true, config.MetadataReporterPurgeDeleted());
   EXPECT_EQ("foobar/foobaz", config.MetadataReporterUserAgent());
   EXPECT_EQ("/a/b/c", config.HealthCheckFile());
 }
 
-TEST_F(MetadataAgentConfigurationTest, CommentSkipped) {
-  ParseConfiguration(
+TEST(MetadataAgentConfigurationTest, CommentSkipped) {
+  MetadataAgentConfiguration config(std::istringstream(
       "ProjectId: TestProjectId\n"
       "#MetadataApiNumThreads: 13\n"
       "MetadataReporterPurgeDeleted: true\n"
-  );
+  ));
   EXPECT_EQ(3, config.MetadataApiNumThreads());
 }
 
-TEST_F(MetadataAgentConfigurationTest, BlankLine) {
-  ParseConfiguration(
+TEST(MetadataAgentConfigurationTest, BlankLine) {
+  MetadataAgentConfiguration config(std::istringstream(
       "ProjectId: TestProjectId\n"
       "\n"
       "\n"
       "MetadataReporterPurgeDeleted: true\n"
-  );
+  ));
   EXPECT_EQ("TestProjectId", config.ProjectId());
   EXPECT_EQ(true, config.MetadataReporterPurgeDeleted());
 }

test/health_checker_unittest.cc

@@ -22,35 +22,32 @@ class HealthCheckerUnittest : public ::testing::Test {
     return health_checker.IsHealthy();
   }
 
-  void SetIsolationPath(const std::string& isolation_path) {
-    isolation_path_ = isolation_path;
-    std::stringstream stream(
-        "HealthCheckFile: './" + isolation_path_ + "/unhealthy'");
-    config_.ParseConfiguration(stream);
-  }
-
-  std::string isolation_path_;
-  MetadataAgentConfiguration config_;
 };
 
+namespace {
+std::istringstream IsolationPathConfig(const std::string& test_name) {
+  return std::istringstream("HealthCheckFile: './" + test_name + "/unhealthy'");
+}
+}  // namespace
+
 TEST_F(HealthCheckerUnittest, DefaultHealthy) {
-  SetIsolationPath(test_info_->name());
-  HealthChecker health_checker(config_);
+  MetadataAgentConfiguration config(IsolationPathConfig(test_info_->name()));
+  HealthChecker health_checker(config);
   EXPECT_TRUE(IsHealthy(health_checker));
   Cleanup(&health_checker);
 }
 
 TEST_F(HealthCheckerUnittest, SimpleFailure) {
-  SetIsolationPath(test_info_->name());
-  HealthChecker health_checker(config_);
+  MetadataAgentConfiguration config(IsolationPathConfig(test_info_->name()));
+  HealthChecker health_checker(config);
   SetUnhealthy(&health_checker, "kubernetes_pod_thread");
   EXPECT_FALSE(IsHealthy(health_checker));
   Cleanup(&health_checker);
 }
 
 TEST_F(HealthCheckerUnittest, MultiFailure) {
-  SetIsolationPath(test_info_->name());
-  HealthChecker health_checker(config_);
+  MetadataAgentConfiguration config(IsolationPathConfig(test_info_->name()));
+  HealthChecker health_checker(config);
   EXPECT_TRUE(IsHealthy(health_checker));
   SetUnhealthy(&health_checker, "kubernetes_pod_thread");
   EXPECT_FALSE(IsHealthy(health_checker));
@@ -60,8 +57,8 @@ TEST_F(HealthCheckerUnittest, MultiFailure) {
 }
 
 TEST_F(HealthCheckerUnittest, FailurePersists) {
-  SetIsolationPath(test_info_->name());
-  HealthChecker health_checker(config_);
+  MetadataAgentConfiguration config(IsolationPathConfig(test_info_->name()));
+  HealthChecker health_checker(config);
   EXPECT_TRUE(IsHealthy(health_checker));
   SetUnhealthy(&health_checker, "kubernetes_pod_thread");
   EXPECT_FALSE(IsHealthy(health_checker));