Introducing the attribute "host group name" that allows interprocess …

…communication across host borders

ecal/core/cfg/ecal.ini

@@ -170,9 +170,11 @@ filter_excl               = ^eCALSysClient$|^eCALSysGUI$|^eCALSys$
 ; shm_monitoring_enabled      = false              Enable distribution of monitoring/registration information via shared memory
 ; shm_monitoring_domain       = ecal_monitoring    Domain name for shared memory based monitoring/registration
 ; shm_monitoring_queue_size   = 1024               Queue size of monitoring/registration events
-; network_monitoring_disabled = false              Disable distribution of monitoring/registration information via network (default)
+; network_monitoring_disabled = false              Disable distribution of monitoring/registration information via network
 ;
 ; drop_out_of_order_messages  = false              Enable dropping of payload messages that arrive out of order
+;
+; host_group_name             = ""                 Common host group name that enables interprocess mechanisms across (virtual) host borders (e.g, Docker); by default equivalent to local host name
 ; --------------------------------------------------
 [experimental]
 shm_monitoring_enabled      = false
@@ -181,3 +183,5 @@ shm_monitoring_queue_size   = 1024
 network_monitoring_disabled = false
 
 drop_out_of_order_messages  = false
+
+host_group_name             = ""

ecal/core/include/ecal/ecal_config.h

@@ -128,6 +128,7 @@ namespace eCAL
       ECAL_API size_t            GetShmMonitoringQueueSize          ();
       ECAL_API std::string       GetShmMonitoringDomain             ();
       ECAL_API bool              GetDropOutOfOrderMessages          ();
+      ECAL_API std::string       GetHostGroupName                   ();
     }
   }
 }

ecal/core/include/ecal/ecal_monitoring_struct.h

@@ -59,6 +59,7 @@ namespace eCAL
       int                                 rclock;               //!< registration clock (heart beat)
       int                                 hid;                  //!< host id
       std::string                         hname;                //!< host name
+      std::string                         hgname;               //!< host group name
       int                                 pid;                  //!< process id
       std::string                         pname;                //!< process name
       std::string                         uname;                //!< unit name

ecal/core/include/ecal/ecal_process.h

@@ -55,6 +55,13 @@ namespace eCAL
     **/
     ECAL_API std::string GetHostName();
 
+    /**
+    * @brief  Get current host group name.
+    *
+    * @return  Host group name or empty string if failed.
+    **/
+    ECAL_API std::string GetHostGroupName();
+
     /**
      * @brief  Get unique host id.
      *

ecal/core/src/ecal_config.cpp

@@ -188,6 +188,7 @@ namespace eCAL
       ECAL_API size_t            GetShmMonitoringQueueSize          () { return static_cast<size_t>(eCALPAR(EXP, SHM_MONITORING_QUEUE_SIZE)); }
       ECAL_API std::string       GetShmMonitoringDomain             () { return eCALPAR(EXP, SHM_MONITORING_DOMAIN);}
       ECAL_API bool              GetDropOutOfOrderMessages          () { return eCALPAR(EXP, DROP_OUT_OF_ORDER_MESSAGES); }
+      ECAL_API std::string       GetHostGroupName                   () { return eCALPAR(EXP, HOST_GROUP_NAME); }
     }
   }
 }

ecal/core/src/ecal_def.h

@@ -173,7 +173,7 @@
 /**********************************************************************************************/
 /* enable distribution of monitoring/registration information via shared memory */
 #define EXP_SHM_MONITORING_ENABLED                  false
-/* disable distribution of monitoring/registration information via network (default) */
+/* disable distribution of monitoring/registration information via network */
 #define EXP_NETWORK_MONITORING_DISABLED             false
 /* queue size of monitoring/registration events  */
 #define EXP_SHM_MONITORING_QUEUE_SIZE               1024
@@ -184,3 +184,6 @@
 
 /* enable dropping of payload messages that arrive out of order */
 #define EXP_DROP_OUT_OF_ORDER_MESSAGES              false
+
+/* common host group name that enables interprocess mechanisms across (virtual) host borders (e.g, Docker); by default equivalent to local host name */
+#define EXP_HOST_GROUP_NAME                         ""

ecal/core/src/ecal_def_ini.h

@@ -122,3 +122,4 @@
 #define  EXP_SHM_MONITORING_QUEUE_SIZE_S     "shm_monitoring_queue_size"
 #define  EXP_SHM_MONITORING_DOMAIN_S         "shm_monitoring_domain"
 #define  EXP_DROP_OUT_OF_ORDER_MESSAGES_S    "drop_out_of_order_messages"
+#define  EXP_HOST_GROUP_NAME_S               "host_group_name"

ecal/core/src/ecal_process.cpp

@@ -320,6 +320,11 @@ namespace eCAL
       return(g_host_name);
     }
 
+    std::string GetHostGroupName()
+    {
+      return Config::Experimental::GetHostGroupName().empty() ? GetHostName() : Config::Experimental::GetHostGroupName();
+    }
+
     int GetHostID()
     {
       return internal::GetHostID();

ecal/core/src/ecal_registration_receiver.cpp

@@ -112,7 +112,8 @@ namespace eCAL
                          m_callback_process(nullptr),
                          m_use_network_monitoring(false),
                          m_use_shm_monitoring(false),
-                         m_callback_custom_apply_sample([](const auto&){})
+                         m_callback_custom_apply_sample([](const auto&){}),
+                         m_host_group_name(Process::GetHostGroupName())
 
   {
   }
@@ -310,8 +311,8 @@ namespace eCAL
 
   void CRegistrationReceiver::ApplySubscriberRegistration(const eCAL::pb::Sample& ecal_sample_)
   {
-    // process local registrations
-    if (IsLocalHost(ecal_sample_))
+    // process registrations from same host group
+    if (IsHostGroupMember(ecal_sample_))
     {
       // do not register local entities, only if loop back flag is set true
       if (m_loopback || (ecal_sample_.topic().pid() != Process::GetProcessID()))
@@ -357,8 +358,8 @@ namespace eCAL
 
   void CRegistrationReceiver::ApplyPublisherRegistration(const eCAL::pb::Sample& ecal_sample_)
   {
-    // process local registrations
-    if (IsLocalHost(ecal_sample_))
+    // process registrations from same host group 
+    if (IsHostGroupMember(ecal_sample_))
     {
       // do not register local entities, only if loop back flag is set true
       if (m_loopback || (ecal_sample_.topic().pid() != Process::GetProcessID()))
@@ -402,11 +403,15 @@ namespace eCAL
     }
   }
 
-  bool CRegistrationReceiver::IsLocalHost(const eCAL::pb::Sample& ecal_sample_)
+  bool CRegistrationReceiver::IsHostGroupMember(const eCAL::pb::Sample& ecal_sample_)
   {
-    const std::string host_name = ecal_sample_.topic().hname();
-    if (host_name.empty()) return false;
-    if (host_name != eCAL::Process::GetHostName()) return false;
+    const std::string sample_host_group_name = ecal_sample_.topic().hgname().empty() ? ecal_sample_.topic().hname() : ecal_sample_.topic().hgname();
+
+    if (sample_host_group_name.empty() || m_host_group_name.empty()) 
+      return false;
+    if (sample_host_group_name != m_host_group_name) 
+      return false;
+
     return true;
   }
 

ecal/core/src/ecal_registration_receiver.h

@@ -97,30 +97,32 @@ namespace eCAL
     void ApplySubscriberRegistration(const eCAL::pb::Sample& ecal_sample_);
     void ApplyPublisherRegistration(const eCAL::pb::Sample& ecal_sample_);
 
-    bool IsLocalHost(const eCAL::pb::Sample & ecal_sample_);
-
-    static std::atomic<bool>  m_created;
-    bool                      m_network;
-    bool                      m_loopback;
-
-    RegistrationCallbackT     m_callback_pub;
-    RegistrationCallbackT     m_callback_sub;
-    RegistrationCallbackT     m_callback_service;
-    RegistrationCallbackT     m_callback_client;
-    RegistrationCallbackT     m_callback_process;
-
-    CUDPReceiver              m_reg_rcv;
-    CThread                   m_reg_rcv_thread;
-    CUdpRegistrationReceiver  m_reg_rcv_process;
+    bool IsHostGroupMember(const eCAL::pb::Sample & ecal_sample_);
+
+    static std::atomic<bool>         m_created;
+    bool                             m_network;
+    bool                             m_loopback;
+                                     
+    RegistrationCallbackT            m_callback_pub;
+    RegistrationCallbackT            m_callback_sub;
+    RegistrationCallbackT            m_callback_service;
+    RegistrationCallbackT            m_callback_client;
+    RegistrationCallbackT            m_callback_process;
+                                     
+    CUDPReceiver                     m_reg_rcv;
+    CThread                          m_reg_rcv_thread;
+    CUdpRegistrationReceiver         m_reg_rcv_process;
 
     eCAL::CMemoryFileBroadcast       m_memfile_broadcast;
     eCAL::CMemoryFileBroadcastReader m_memfile_broadcast_reader;
     CMemfileRegistrationReceiver     m_memfile_reg_rcv;
     CThread                          m_memfile_reg_rcv_thread;
 
-    bool m_use_network_monitoring;
-    bool m_use_shm_monitoring;
+    bool                             m_use_network_monitoring;
+    bool                             m_use_shm_monitoring;
+
+    ApplySampleCallbackT             m_callback_custom_apply_sample;
 
-    ApplySampleCallbackT m_callback_custom_apply_sample;
+    std::string                      m_host_group_name;
   };
 };

ecal/core/src/mon/ecal_monitoring_impl.cpp

@@ -304,11 +304,12 @@ namespace eCAL
       const std::lock_guard<std::mutex> lock(pTopicMap->sync);
 
       // common infos
-      const int          host_id      = sample_topic.hid();
-      const std::string& host_name    = sample_topic.hname();
-      const std::string& process_name = sample_topic.pname();
-      const std::string& unit_name    = sample_topic.uname();
-      const std::string& topic_id     = sample_topic.tid();
+      const int          host_id         = sample_topic.hid();
+      const std::string& host_name       = sample_topic.hname();
+      const std::string& host_group_name = sample_topic.hgname();
+      const std::string& process_name    = sample_topic.pname();
+      const std::string& unit_name       = sample_topic.uname();
+      const std::string& topic_id        = sample_topic.tid();
       std::string        direction;
       switch (pubsub_type_)
       {
@@ -333,6 +334,7 @@ namespace eCAL
       // set static content
       TopicInfo.hid       = host_id;
       TopicInfo.hname     = host_name;
+      TopicInfo.hgname    = host_group_name;
       TopicInfo.pid       = process_id;
       TopicInfo.pname     = process_name;
       TopicInfo.uname     = unit_name;
@@ -943,6 +945,9 @@ namespace eCAL
       // host name
       pMonTopic->set_hname(topic.second.hname);
 
+      // host group name
+      pMonTopic->set_hgname(topic.second.hgname);
+
       // process id
       pMonTopic->set_pid(topic.second.pid);
 

ecal/core/src/readwrite/ecal_reader.cpp

@@ -46,6 +46,7 @@ namespace eCAL
   ////////////////////////////////////////
   CDataReader::CDataReader() :
                  m_host_name(Process::GetHostName()),
+                 m_host_group_name(Process::GetHostGroupName()),
                  m_host_id(Process::internal::GetHostID()),
                  m_pid(Process::GetProcessID()),
                  m_pname(Process::GetProcessName()),
@@ -218,6 +219,7 @@ namespace eCAL
     ecal_reg_sample.set_cmd_type(eCAL::pb::bct_reg_subscriber);
     auto *ecal_reg_sample_mutable_topic = ecal_reg_sample.mutable_topic();
     ecal_reg_sample_mutable_topic->set_hname(m_host_name);
+    ecal_reg_sample_mutable_topic->set_hgname(m_host_group_name);
     ecal_reg_sample_mutable_topic->set_hid(m_host_id);
     ecal_reg_sample_mutable_topic->set_tname(m_topic_name);
     ecal_reg_sample_mutable_topic->set_tid(m_topic_id);
@@ -324,6 +326,7 @@ namespace eCAL
     ecal_unreg_sample.set_cmd_type(eCAL::pb::bct_unreg_subscriber);
     auto *ecal_reg_sample_mutable_topic = ecal_unreg_sample.mutable_topic();
     ecal_reg_sample_mutable_topic->set_hname(m_host_name);
+    ecal_reg_sample_mutable_topic->set_hgname(m_host_group_name);
     ecal_reg_sample_mutable_topic->set_hid(m_host_id);
     ecal_reg_sample_mutable_topic->set_pname(m_pname);
     ecal_reg_sample_mutable_topic->set_pid(m_pid);
@@ -980,6 +983,7 @@ namespace eCAL
     out << indent_ << " class CDataReader "                                  << std::endl;
     out << indent_ << "--------------------------------"                     << std::endl;
     out << indent_ << "m_host_name:             " << m_host_name             << std::endl;
+    out << indent_ << "m_host_group_name:       " << m_host_group_name       << std::endl;
     out << indent_ << "m_host_id:               " << m_host_id               << std::endl;
     out << indent_ << "m_topic_name:            " << m_topic_name            << std::endl;
     out << indent_ << "m_topic_id:              " << m_topic_id              << std::endl;

ecal/core/src/readwrite/ecal_reader.h

@@ -116,6 +116,7 @@ namespace eCAL
     bool CheckMessageClock(const std::string& tid_, long long current_clock_);
 
     std::string                               m_host_name;
+    std::string                               m_host_group_name;
     int                                       m_host_id;
     int                                       m_pid;
     std::string                               m_pname;

ecal/core/src/readwrite/ecal_writer.cpp

@@ -66,6 +66,7 @@ namespace eCAL
 {
   CDataWriter::CDataWriter() :
     m_host_name(Process::GetHostName()),
+    m_host_group_name(Process::GetHostGroupName()),
     m_host_id(Process::internal::GetHostID()),
     m_pid(Process::GetProcessID()),
     m_pname(Process::GetProcessName()),
@@ -805,6 +806,7 @@ namespace eCAL
     out << indent_ << " class CDataWriter  "                                 << std::endl;
     out << indent_ << "--------------------------------"                     << std::endl;
     out << indent_ << "m_host_name:             " << m_host_name             << std::endl;
+    out << indent_ << "m_host_group_name:       " << m_host_group_name       << std::endl;
     out << indent_ << "m_host_id:               " << m_host_id               << std::endl;
     out << indent_ << "m_topic_name:            " << m_topic_name            << std::endl;
     out << indent_ << "m_topic_id:              " << m_topic_id              << std::endl;
@@ -843,6 +845,7 @@ namespace eCAL
     ecal_reg_sample.set_cmd_type(eCAL::pb::bct_reg_publisher);
     auto *ecal_reg_sample_mutable_topic = ecal_reg_sample.mutable_topic();
     ecal_reg_sample_mutable_topic->set_hname(m_host_name);
+    ecal_reg_sample_mutable_topic->set_hgname(m_host_group_name);
     ecal_reg_sample_mutable_topic->set_hid(m_host_id);
     ecal_reg_sample_mutable_topic->set_tname(m_topic_name);
     ecal_reg_sample_mutable_topic->set_tid(m_topic_id);
@@ -977,6 +980,7 @@ namespace eCAL
     ecal_unreg_sample.set_cmd_type(eCAL::pb::bct_unreg_publisher);
     auto* ecal_reg_sample_mutable_topic = ecal_unreg_sample.mutable_topic();
     ecal_reg_sample_mutable_topic->set_hname(m_host_name);
+    ecal_reg_sample_mutable_topic->set_hgname(m_host_group_name);
     ecal_reg_sample_mutable_topic->set_hid(m_host_id);
     ecal_reg_sample_mutable_topic->set_pname(m_pname);
     ecal_reg_sample_mutable_topic->set_pid(m_pid);

ecal/core/src/readwrite/ecal_writer.h

@@ -118,6 +118,7 @@ namespace eCAL
     void LogSendMode(TLayer::eSendMode smode_, const std::string & base_msg_);
 
     std::string                        m_host_name;
+    std::string                        m_host_group_name;
     int                                m_host_id;
     int                                m_pid;
     std::string                        m_pname;

ecal/core_pb/src/ecal/core/pb/topic.proto

@@ -54,6 +54,7 @@ message Topic                                     // eCAL topic
   int32              rclock                =  1;  // registration clock (heart beat)
   int32              hid                   = 26;  // host id
   string             hname                 =  2;  // host name
+  string             hgname                = 28;  // host group name
   int32              pid                   =  3;  // process id
   string             pname                 =  4;  // process name
   string             uname                 =  5;  // unit name