add topology load at startup and save to memory and file after each modification

This feature allows to load a topology from file at startup, either from the default folder or from a user selected file, like

polycubed --cubes-dump ~/Desktop/cubes.yaml

keeping the whole configuration in memory.
After each modification in any of the topology of the cube, the configuration in memory is updated and another thread saves it to file updating it too.
It is possible to start the daemon with an empty topology by using the flag --cubes-init: if the file contains a topology, at the first update it is overwritten.
It is possible to start the daemon without the dumping to file functionality by using the flag --cubes-nodump.

Signed-off-by: Riccardo Marchi <riccardo.marchi4@gmail.com>

Author: richiMarchi

src/polycubed/src/CMakeLists.txt

@@ -62,6 +62,7 @@ set(polycubed_sources
   utils/veth.cpp
   utils/netlink.cpp
   utils/utils.cpp
+  cubes_dump.cpp
   ${server_sources}
   ${CMAKE_CURRENT_BINARY_DIR}/load_services.cpp
   ${CMAKE_CURRENT_BINARY_DIR}/version.cpp)

src/polycubed/src/config.cpp

@@ -32,13 +32,17 @@ namespace configuration {
 
 #define LOGLEVEL spdlog::level::level_enum::info
 #define DAEMON false
+#define CUBESINIT false
+#define CUBESNODUMP false
 #define PIDFILE "/var/run/polycube.pid"
 #define SERVER_PORT 9000
 #define SERVER_IP "localhost"
 #define LOGFILE "/var/log/polycube/polycubed.log"
 #define CONFIGFILEDIR "/etc/polycube"
 #define CONFIGFILENAME "polycubed.conf"
+#define CUBESDUMPFILE "cubes.yaml"
 #define CONFIGFILE (CONFIGFILEDIR "/" CONFIGFILENAME)
+#define CUBESDUMPFILEPATH (CONFIGFILEDIR "/" CUBESDUMPFILE)
 
 static void show_usage(const std::string &name) {
   std::cout << std::boolalpha;
@@ -64,6 +68,11 @@ static void show_usage(const std::string &name) {
             << ")" << std::endl;
   std::cout << "--configfile: configuration file (default: " << CONFIGFILE
             << ")" << std::endl;
+  std::cout << "--cubes-dump: file that keeps the last topology, "
+               "including the configuration of all cubes (default: " << CUBESDUMPFILEPATH
+            << ")" << std::endl;
+  std::cout << "--cubes-init: starts the daemon with an empty topology" << std::endl;
+  std::cout << "--cubes-nodump: starts the daemon without dumping updates to file" << std::endl;
   std::cout << "--cert-blacklist: path to black listed certificates"
             << std::endl;
   std::cout << "--cert-whitelist: path to white listed certificates"
@@ -95,7 +104,10 @@ Config::Config()
       server_port(SERVER_PORT),
       server_ip(SERVER_IP),
       logfile(LOGFILE),
-      configfile(CONFIGFILE) {}
+      configfile(CONFIGFILE),
+      cubes_dump_file(CUBESDUMPFILEPATH),
+      cubes_init(CUBESINIT),
+      cubes_nodump(CUBESNODUMP){}
 
 Config::~Config() {}
 
@@ -180,6 +192,31 @@ void Config::setLogFile(const std::string &value) {
   logfile = value;
 }
 
+std::string Config::getCubesDumpFilePath() const {
+  return cubes_dump_file;
+}
+
+void Config::setCubesDumpFilePath(const std::string &value) {
+  CHECK_OVERWRITE("cubes-dump", value, cubes_dump_file, CUBESDUMPFILEPATH);
+  cubes_dump_file = value;
+}
+
+bool Config::getCubesInitTopology() const {
+  return cubes_init;
+}
+
+void Config::setCubesInitTopology() {
+  cubes_init = true;
+}
+
+bool Config::getCubesNoDump() const {
+  return cubes_nodump;
+}
+
+void Config::setCubesNoDump() {
+  cubes_nodump = true;
+}
+
 std::string Config::getCertPath() const {
   return cert_path;
 }
@@ -246,6 +283,8 @@ void Config::create_configuration_file(const std::string &path) {
   file << "addr: " << server_ip << std::endl;
   file << "# file to save polycube logs" << std::endl;
   file << "logfile: " << logfile << std::endl;
+  file << "# file to save last topology" << std::endl;
+  file << "cubes-dump: " << cubes_dump_file << std::endl;
   file << "# Security related:" << std::endl;
   file << "# server certificate " << std::endl;
   file << "#cert: path_to_certificate_file" << std::endl;
@@ -270,6 +309,9 @@ void Config::dump() {
   logger->info(" port: {}", server_port);
   logger->info(" addr: {}", server_ip);
   logger->info(" logfile: {}", logfile);
+  logger->info(" cubes-dump: {}", cubes_dump_file);
+  logger->info(" cubes-init: {}", cubes_init);
+  logger->info(" cubes-nodump: {}", cubes_nodump);
   if (!cert_path.empty()) {
     logger->info(" cert: {}", cert_path);
   }
@@ -363,6 +405,9 @@ static struct option options[] = {
     {"cacert", required_argument, NULL, 5},
     {"cert-whitelist", required_argument, NULL, 6},
     {"cert-blacklist", required_argument, NULL, 7},
+    {"cubes-dump", required_argument, NULL, 8},
+    {"cubes-init", no_argument, NULL, 9},
+    {"cubes-nodump", no_argument, NULL, 10},
     {NULL, 0, NULL, 0},
 };
 
@@ -408,6 +453,15 @@ void Config::load_from_cli(int argc, char *argv[]) {
     case 7:
       setCertBlacklistPath(optarg);
       break;
+    case 8:
+      setCubesDumpFilePath(optarg);
+      break;
+    case 9:
+      setCubesInitTopology();
+      break;
+    case 10:
+      setCubesNoDump();
+      break;
     }
   }
 }

src/polycubed/src/config.h

@@ -53,6 +53,18 @@ class Config {
   std::string getLogFile() const;
   void setLogFile(const std::string &value);
 
+  // file where last topology is saved
+  std::string getCubesDumpFilePath() const;
+  void setCubesDumpFilePath(const std::string &value);
+
+  // set to get an empty topology
+  bool getCubesInitTopology() const;
+  void setCubesInitTopology();
+
+  // set to avoid daemon to dump updates to file
+  bool getCubesNoDump() const;
+  void setCubesNoDump();
+
   // path of certificate & key to be used in server
   std::string getCertPath() const;
   void setCertPath(const std::string &value);
@@ -80,11 +92,14 @@ class Config {
 
   spdlog::level::level_enum loglevel;
   bool daemon;
+  bool cubes_init;
+  bool cubes_nodump;
   std::string pidfile;
   uint16_t server_port;
   std::string server_ip;
   std::string logfile;
   std::string configfile;
+  std::string cubes_dump_file;
   std::string cert_path, key_path;
   std::string cacert_path;
   std::string cert_whitelist_path;