restructured zenserver configuration (#575)

this breaks out the configuration logic to allow multiple applications to share common configuration and initialization logic whilst customizing chosen aspects of the process

1 files changed, 40 insertions, 14 deletions

diff --git a/src/zenserver/config/config.h b/src/zenserver/config/config.h
index 8471ee89b..467f26ee7 100644
--- a/src/zenserver/config/config.h
+++ b/src/zenserver/config/config.h
@@ -19,7 +19,7 @@ class ParseResult;
 }  // namespace cxxopts
 namespace zen {
 
-struct ZenStorageServerOptions;
+// Common server configuration
 
 struct ZenStatsConfig
 {
@@ -37,10 +37,11 @@ struct ZenSentryConfig
 	bool		Debug = false;	// Enable debug mode for Sentry
 };
 
-struct ZenServerOptions
+struct ZenServerConfig
 {
 	HttpServerConfig	  HttpServerConfig;
 	ZenSentryConfig		  SentryConfig;
+	ZenStatsConfig		  StatsConfig;
 	int					  BasePort		  = 8558;  // Service listen port (used for both UDP and TCP)
 	int					  OwnerPid		  = 0;	   // Parent process id (zero for standalone)
 	bool				  IsDebug		  = false;
@@ -54,13 +55,14 @@ struct ZenServerOptions
 	bool				  IsDedicated	  = false;	// Indicates a dedicated/shared instance, with larger resource requirements
 	bool				  ShouldCrash	  = false;	// Option for testing crash handling
 	bool				  IsFirstRun	  = false;
-	std::filesystem::path ConfigFile;	  // Path to Lua config file
-	std::filesystem::path SystemRootDir;  // System root directory (used for machine level config)
-	std::filesystem::path ContentDir;	  // Root directory for serving frontend content (experimental)
-	std::filesystem::path DataDir;		  // Root directory for state (used for testing)
-	std::filesystem::path AbsLogFile;	  // Absolute path to main log file
-	std::string			  ChildId;		  // Id assigned by parent process (used for lifetime management)
-	std::string			  LogId;		  // Id for tagging log output
+	std::filesystem::path ConfigFile;		// Path to Lua config file
+	std::filesystem::path SystemRootDir;	// System root directory (used for machine level config)
+	std::filesystem::path ContentDir;		// Root directory for serving frontend content (experimental)
+	std::filesystem::path DataDir;			// Root directory for state (used for testing)
+	std::filesystem::path AbsLogFile;		// Absolute path to main log file
+	std::filesystem::path BaseSnapshotDir;	// Path to server state snapshot (will be copied into data dir on start)
+	std::string			  ChildId;			// Id assigned by parent process (used for lifetime management)
+	std::string			  LogId;			// Id for tagging log output
 	std::string			  Loggers[zen::logging::level::LogLevelCount];
 #if ZEN_WITH_TRACE
 	bool		 HasTraceCommandlineOptions = false;
@@ -71,17 +73,41 @@ struct ZenServerOptions
 	std::string EncryptionKey;	// 256 bit AES encryption key
 	std::string EncryptionIV;	// 128 bit AES initialization vector
 
-	ZenStatsConfig StatsConfig;
-
 	bool InstallService	  = false;	// Flag used to initiate service install (temporary)
 	bool UninstallService = false;	// Flag used to initiate service uninstall (temporary)
 };
 
-void ParseCliOptions(int argc, char* argv[], ZenStorageServerOptions& ServerOptions);
+/** Configuration helper - pulls together command line, environment variables
+	and config file parsing logic. Designed to allow a set of common configuration
+	options to be shared among a set of applications which may or may not all be
+	linked into a single executable.
+
+	The virtual functions are used by derived classes to extend and customize the
+	configuration process.
+ */
+struct ZenServerConfiguratorBase
+{
+	ZenServerConfiguratorBase(ZenServerConfig& BaseServerOptions);
+	virtual ~ZenServerConfiguratorBase();
+
+	void Configure(int argc, char* argv[]);
+
+protected:
+	virtual void AddCliOptions(cxxopts::Options& options)			= 0;
+	virtual void ApplyOptions(cxxopts::Options& options)			= 0;
+	virtual void ValidateOptions()									= 0;
+	virtual void AddConfigOptions(LuaConfig::Options& Options)		= 0;
+	virtual void OnConfigFileParsed(LuaConfig::Options& LuaOptions) = 0;
+
+private:
+	ZenServerConfig& m_ServerOptions;
+
+	void ParseEnvVariables(const cxxopts::ParseResult& CmdLineResult);
+	void ParseConfigFile(const std::filesystem::path& Path, const cxxopts::ParseResult& CmdLineResult, std::string_view OutputConfigFile);
+	void AddCommonConfigOptions(LuaConfig::Options& LuaOptions);
+};
 
 void EmitCentralManifest(const std::filesystem::path& SystemRoot, Oid Identifier, CbObject Manifest, std::filesystem::path ManifestPath);
 std::vector<CbObject> ReadAllCentralManifests(const std::filesystem::path& SystemRoot);
 
-void AddServerConfigOptions(LuaConfig::Options& LuaOptions, ZenServerOptions& ServerOptions);
-
 }  // namespace zen