add system stats subscriber

rosboard/html/js/index.js

@@ -138,7 +138,13 @@ let onTopics = function(topics) {
   $('<a></a>')
   .addClass("mdl-navigation__link")
   .click(() => { initSubscribe({topicName: "_top", topicType: "rosboard_msgs/msg/ProcessList"}); })
-  .text("top")
+  .text("Processes")
+  .appendTo($("#topics-nav-system"));
+
+  $('<a></a>')
+  .addClass("mdl-navigation__link")
+  .click(() => { initSubscribe({topicName: "_system_stats", topicType: "rosboard_msgs/msg/SystemStats"}); })
+  .text("System stats")
   .appendTo($("#topics-nav-system"));
 }
 

rosboard/rosboard.py

@@ -21,6 +21,7 @@
 from rosboard.serialization import ros2dict
 from rosboard.subscribers.dmesg_subscriber import DMesgSubscriber
 from rosboard.subscribers.processes_subscriber import ProcessesSubscriber
+from rosboard.subscribers.system_stats_subscriber import SystemStatsSubscriber
 from rosboard.subscribers.dummy_subscriber import DummySubscriber
 from rosboard.handlers import ROSBoardSocketHandler, NoCacheStaticFileHandler
 
@@ -181,6 +182,12 @@ def sync_subs(self):
                         self.local_subs[topic_name] = DMesgSubscriber(self.on_dmesg)
                     continue
 
+                if topic_name == "_system_stats":
+                    if topic_name not in self.local_subs:
+                        rospy.loginfo("Subscribing to _system_stats [non-ros]")
+                        self.local_subs[topic_name] = SystemStatsSubscriber(self.on_system_stats)
+                    continue
+
                 if topic_name == "_top":
                     if topic_name not in self.local_subs:
                         rospy.loginfo("Subscribing to _top [non-ros]")
@@ -240,6 +247,29 @@ def sync_subs(self):
 
         self.lock.release()
 
+    def on_system_stats(self, system_stats):
+        """
+        system stats received. send it off to the client as a "fake" ROS message (which could at some point be a real ROS message)
+        """
+        if self.event_loop is None:
+            return
+
+        msg_dict = {
+            "_topic_name": "_system_stats", # special non-ros topics start with _
+            "_topic_type": "rosboard_msgs/msg/SystemStats",
+        }
+
+        for key, value in system_stats.items():
+            msg_dict[key] = value
+
+        self.event_loop.add_callback(
+            ROSBoardSocketHandler.broadcast,
+            [
+                ROSBoardSocketHandler.MSG_MSG,
+                msg_dict
+            ]
+        )
+
     def on_top(self, processes):
         """
         processes list received. send it off to the client as a "fake" ROS message (which could at some point be a real ROS message)

rosboard/subscribers/system_stats_subscriber.py

@@ -1,50 +1,69 @@
 #!/usr/bin/env python3
 
-import psutil
-import select
-import subprocess
+try:
+    import psutil
+except (ImportError, ModuleNotFoundError) as e:
+    psutil = None
+
 import time
 import threading
 import traceback
 
+def mean(list):
+    return sum(list)/len(list)
+
 class SystemStatsSubscriber(object):
     def __init__(self, callback):
         self.callback = callback
-        self.process = None
+        self.stop = False
         threading.Thread(target = self.start, daemon = True).start()
 
     def __del__(self):
-        if self.process:
-            self.process.terminate()
-            self.process = None
+        self.stop = True
+        pass
 
     def unregister(self):
-        if self.process:
-            self.process.terminate()
-            self.process = None
+        self.stop = True
+        pass
 
     def start(self):
-        try:
-            self.process = subprocess.Popen(['dmesg', '--follow'], stdout = subprocess.PIPE)
-            p = select.poll()
-            p.register(self.process.stdout, select.POLLIN)
-
-            while True:
-                time.sleep(0.1)
-
-                if self.process is None:
-                    break
+        if psutil is None:
+            self.callback({"_error": "Please install psutil (sudo pip3 install --upgrade psutil) to use this feature."})
+            return
+
+        while not self.stop:
+            try:
+                p = psutil.Process()
+
+                with p.oneshot():
+                    sensors_temperatures = psutil.sensors_temperatures()
+                    cpu_percent = psutil.cpu_percent(percpu = True)
+                    net_io_counters = psutil.net_io_counters()
+                    virtual_memory = psutil.virtual_memory()
+                    swap_memory = psutil.swap_memory()
+                    disk_usage = psutil.disk_usage('/')
+
+                status = {}
+
+                status["cpu_percent"] = cpu_percent
+
+                if "coretemp" in sensors_temperatures:
+                    status["temp_coretemp"] = mean(list(map(
+                        lambda x:x.current,
+                        sensors_temperatures["coretemp"]
+                    )))
 
-                lines = []
-                while p.poll(1):
-                    lines.append(self.process.stdout.readline().decode('utf-8').strip())
+                status["net_bytes_sent"] = net_io_counters.bytes_sent
+                status["net_bytes_recv"] = net_io_counters.bytes_recv
+                status["disk_usage_percent"] = disk_usage.percent
+                status["virtual_memory_percent"] = virtual_memory.percent
+                status["swap_memory_percent"] = swap_memory.percent
 
-                text = "\n".join(lines)
-                if len(text) > 0:
-                    self.callback("\n".join(lines))
-        except:
-            traceback.print_exc()
+            except Exception as e:
+                traceback.print_exc()
 
+            self.callback(status)
+            time.sleep(3)
 
 if __name__ == "__main__":
     # Run test