new(userspace/falco): allow --support to print expanded configuration file.

Signed-off-by: Federico Di Pierro <nierro92@gmail.com>

userspace/falco/app/actions/print_support.cpp

@@ -108,7 +108,7 @@ falco::app::run_result falco::app::actions::print_support(falco::app::state& s)
 		support["version"] = infos.falco_version;
 		support["engine_info"] = infos.as_json();
 		support["cmdline"] = s.cmdline;
-		support["config"] = read_file(s.options.conf_filename);
+		support["config"] = s.config->dump();
 		support["rules_files"] = nlohmann::json::array();
 		for(const auto& filename : s.config->m_loaded_rules_filenames)
 		{

userspace/falco/configuration.cpp

@@ -85,16 +85,14 @@ falco_configuration::falco_configuration():
 
 void falco_configuration::init(const std::vector<std::string>& cmdline_options)
 {
-	yaml_helper config;
 	config.load_from_string("");
-	init_cmdline_options(config, cmdline_options);
+	init_cmdline_options(cmdline_options);
-	load_yaml("default", config);
+	load_yaml("default");
 }
 
 void falco_configuration::init(const std::string& conf_filename, std::vector<std::string>& loaded_conf_files,
 			       std::vector<std::string>& loaded_conf_warnings, const std::vector<std::string> &cmdline_options)
 {
-	yaml_helper config;
 	try
 	{
 		config.load_from_file(conf_filename, loaded_conf_files, loaded_conf_warnings);
@@ -104,11 +102,16 @@ void falco_configuration::init(const std::string& conf_filename, std::vector<std
 		std::cerr << "Cannot read config file (" + conf_filename + "): " + e.what() + "\n";
 		throw e;
 	}
-	init_cmdline_options(config, cmdline_options);
+	init_cmdline_options(cmdline_options);
-	load_yaml(conf_filename, config);
+	load_yaml(conf_filename);
 }
 
-void falco_configuration::load_engine_config(const std::string& config_name, const yaml_helper& config)
+std::string falco_configuration::dump()
+{
+	return config.dump();
+}
+
+void falco_configuration::load_engine_config(const std::string& config_name)
 {
 	// Set driver mode if not already set.
 	const std::unordered_map<std::string, engine_kind_t> engine_mode_lut = {
@@ -177,9 +180,9 @@ void falco_configuration::load_engine_config(const std::string& config_name, con
 	}
 }
 
-void falco_configuration::load_yaml(const std::string& config_name, const yaml_helper& config)
+void falco_configuration::load_yaml(const std::string& config_name)
 {
-	load_engine_config(config_name, config);
+	load_engine_config(config_name);
 	m_log_level = config.get_scalar<std::string>("log_level", "info");
 
 	std::list<std::string> rules_files;
@@ -588,15 +591,15 @@ static bool split(const std::string &str, char delim, std::pair<std::string, std
 	return true;
 }
 
-void falco_configuration::init_cmdline_options(yaml_helper& config, const std::vector<std::string> &cmdline_options)
+void falco_configuration::init_cmdline_options(const std::vector<std::string> &cmdline_options)
 {
 	for(const std::string &option : cmdline_options)
 	{
-		set_cmdline_option(config, option);
+		set_cmdline_option(option);
 	}
 }
 
-void falco_configuration::set_cmdline_option(yaml_helper& config, const std::string &opt)
+void falco_configuration::set_cmdline_option(const std::string &opt)
 {
 	std::pair<std::string, std::string> keyval;
 

userspace/falco/configuration.h

@@ -89,6 +89,8 @@ public:
 	void init(const std::string& conf_filename, std::vector<std::string>& loaded_conf_files, std::vector<std::string>& loaded_conf_warnings, const std::vector<std::string>& cmdline_options);
 	void init(const std::vector<std::string>& cmdline_options);
 
+	std::string dump();
+
 	static void read_rules_file_directory(const std::string& path, std::list<std::string>& rules_filenames, std::list<std::string> &rules_folders);
 
 	// Rules list as passed by the user
@@ -162,11 +164,11 @@ public:
 	gvisor_config m_gvisor = {};
 
 private:
-	void load_yaml(const std::string& config_name, const yaml_helper& config);
+	void load_yaml(const std::string& config_name);
 
-	void load_engine_config(const std::string& config_name, const yaml_helper& config);
+	void load_engine_config(const std::string& config_name);
 
-	void init_cmdline_options(yaml_helper& config, const std::vector<std::string>& cmdline_options);
+	void init_cmdline_options(const std::vector<std::string>& cmdline_options);
 
 	/**
 	 * Given a <key>=<value> specifier, set the appropriate option
@@ -174,7 +176,9 @@ private:
 	 * characters for nesting. Currently only 1- or 2- level keys
 	 * are supported and only scalar values are supported.
 	 */
-	void set_cmdline_option(yaml_helper& config, const std::string& spec);
+	void set_cmdline_option(const std::string& spec);
+
+	yaml_helper config;
 };
 
 namespace YAML {

userspace/falco/yaml_helper.h

@@ -215,6 +215,13 @@ public:
 		return node.IsDefined();
 	}
 
+	std::string dump() const
+	{
+		YAML::Emitter emitter;
+		emitter << YAML::DoubleQuoted << YAML::Flow << YAML::LowerNull << YAML::BeginSeq << m_root;
+		return emitter.c_str() + 1; // drop initial '[' char
+	}
+
 private:
 	YAML::Node m_root;