updated message structure

msg/Metric.msg

-string  key      # Label of the value.
-string  val      # Value to track.
-string  unit     # Unit of the value.
-float32 err_lvl  # Error level of the value.
+string  key      # Label of the metric.
+string  value    # Value of the metric.
+string  unit     # Unit of the metric.
+float32 critical # Critical level of the metric.
\ No newline at end of file

msg/Monitoring.msg

+string origin # Origin of the monitoring message.
+Metric metric # Monitored metric.
\ No newline at end of file

scripts/monitor.py

 #!/usr/bin/env python
+import socket
 import rospy
+from monitoring.msg import Monitoring
 from monitoring.msg import Metric
 
 
@@ -8,36 +10,37 @@ class Monitor:
         self.log = {}  # Logging dictionary. Is used to accomplish different publishing modes.
         self.pub = rospy.Publisher('metric', Metric, queue_size=1)
         self.mode = mode
-        self.metric = Metric()
+        self.monitoring = Monitoring()
+        self.monitoring.origin = socket.gethostname() + rospy.get_name()
 
         if not freq > 0:
             rospy.logwarn("Frequency must be greater then 0! Using 1 as frequency!")
             freq = 1
 
-        self.timer = rospy.Timer(rospy.Duration(1.0 / freq), self.publish_metric)
+        self.timer = rospy.Timer(rospy.Duration(1.0 / freq), self.publish_monitoring)
 
-    def reset_metric(self):
-        self.metric = Metric()
+    # At the moment the last metric update ist published over and over.
+    def publish_monitoring(self):
+        self.pub.publish(self.monitoring)
 
-    def publish_metric(self):
-        self.pub.publish(self.metric)
-        self.reset_metric()
-
-    def update_metric(self, key, val, unit, err_lvl):
+    def update_metric(self, key, value, unit, critical):
         def set_metric():
-            self.metric.key = key
-            self.metric.val = val
-            self.metric.unit = unit
-            self.metric.err_lvl = err_lvl
+            metric = Metric()
+            metric.key = key
+            metric.value = value
+            metric.unit = unit
+            metric.critical = critical
+
+            self.monitoring.metric = metric
 
         def rst_key():  # Reset the value of a key in the logging dictionary.
             self.log[key] = {'num': 0, 'val': 0, 'sum': 0, 'dur': rospy.get_rostime()}
 
         if " " in key:  # A key cannot contain whitespace!
             rospy.logwarn("Whitespaces are not allowed in metric keys!")
+        elif critical > 1 or critical < 0:
+            rospy.logwarn("Critical level must be between 1 and 0!")
         else:
-            self.reset_metric()  # Reset metric.
-
             if key in self.log:
                 # Mode 1: Set the last obtained value.
                 if self.mode == 1:
@@ -46,32 +49,32 @@ class Monitor:
                 # Mode 2: Remember and set the minimum value,
                 #         obtained after mode selection.
                 elif self.mode == 2:
-                    if val < self.log[key]['val']:
-                        self.log[key]['val'] = val
+                    if value < self.log[key]['val']:
+                        self.log[key]['val'] = value
                     else:
-                        val = self.log[key]['val']
+                        value = self.log[key]['val']
 
                     set_metric()
 
                 # Mode 3: Remember and set the maximum value,
                 #         obtained after mode selection.
                 elif self.mode == 3:
-                    if val > self.log[key]['val']:
-                        self.log[key]['val'] = val
+                    if value > self.log[key]['val']:
+                        self.log[key]['val'] = value
                     else:
-                        val = self.log[key]['val']
+                        value = self.log[key]['val']
 
                     set_metric()
 
                 # Mode 4: Set the average obtained value over five
-                #         seconds.
+                #         or more seconds.
                 elif self.mode == 4:
-                    dur = rospy.get_rostime() - self.log[key]['dur']
-                    if dur < rospy.Duration(5):
+                    duration = rospy.get_rostime() - self.log[key]['dur']
+                    if duration < rospy.Duration(5):
                         self.log[key]['num'] += 1
-                        self.log[key]['sum'] += val
+                        self.log[key]['sum'] += value
                     else:
-                        val = self.log[key]['sum'] / (self.log[key]['num'] + 0.001)
+                        value = self.log[key]['sum'] / (self.log[key]['num'] + 0.001)
                         set_metric()
                         rst_key()
             else:

scripts/watchdog.py

@@ -2,3 +2,14 @@
 import rospy
 from monitoring.msg import Metric
 
+class Watchdog:
+    def __init__(self):
+        self.state = 0
+        self.observing = {}
+        rospy.init_node("watchdog")
+        rospy.Subscriber("metric", Metric, callback)
+
+    def callback(self, monitoring):
+
+        if monitoring.origin in self.observing:
+            self.observing[metric]
\ No newline at end of file