diff --git a/setup/start/collectd/du.py b/setup/start/collectd/du.py
index ed3b9d8ad..14e5b0568 100644
--- a/setup/start/collectd/du.py
+++ b/setup/start/collectd/du.py
@@ -1,4 +1,4 @@
-import collectd,os,subprocess,sys
+import collectd,os,subprocess,sys,re
 
 # https://www.programcreek.com/python/example/106897/collectd.register_read
 
@@ -17,7 +17,23 @@ def du(pathinfo):
         return size
     except Exception as e:
         collectd.info('\terror getting the size of %s: %s' % (pathinfo['dir'], str(e)))
-        return -1
+        return 0
+
+def parseSize(size):
+    units = {"B": 1, "KB": 10**3, "MB": 10**6, "GB": 10**9, "TB": 10**12}
+    number, unit, _ = re.split('([a-zA-Z]+)', size.upper())
+    return int(float(number)*units[unit])
+
+def dockerSize():
+    # use --format '{{json .}}' to dump the string. '{{if eq .Type "Images"}}{{.Size}}{{end}}' still creates newlines
+    cmd = 'timeout 1800 docker system df --format "{{.Size}}" | head -n1'
+    try:
+        size = subprocess.check_output(cmd, shell=True).strip().decode('utf-8')
+        collectd.info('\tsize of docker images is %s' % size)
+        return parseSize(size)
+    except Exception as e:
+        collectd.info('\terror getting docker images size : %s' % str(e))
+        return 0
 
 # configure is called for each module block. this is called before init
 def configure(config):
@@ -50,9 +66,14 @@ def read():
 
         # type comes from https://github.com/collectd/collectd/blob/master/src/types.db
         val = collectd.Values(type='capacity', plugin='du', plugin_instance=pathinfo['name'])
-
         val.dispatch(values=[size], type_instance='usage')
 
+    size = dockerSize()
+    val = collectd.Values(type='capacity', plugin='du', plugin_instance='docker')
+    val.dispatch(values=[size], type_instance='usage')
+
+
+
 collectd.register_init(init)
 collectd.register_config(configure)
 collectd.register_read(read, INTERVAL)