Merge pull request #4 from p00rt/master

Add a check to watch for available RAM and a test for this check

app/checks-tests/free_ram_test.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+echo " >> Assert that 2GB free (3/5GB used) is ok when max usage is 70%"
+MOCK_FREE_RAM=3000 MOCK_TOTAL_RAM=5000 MAX_RAM_PERCENTAGE=70 ../checks/free_ram.py
+[[ $? == 1 ]] && echo " .. Test failed." && exit 1
+[[ $? == 127 ]] && echo " .. Test lacking a parameter." && exit 127
+
+echo " >> Assert that 2GB free (8/10GB used) is too much when max usage is 60%"
+MOCK_FREE_RAM=2000 MOCK_TOTAL_RAM=10000 MAX_RAM_PERCENTAGE=60 ../checks/free_ram.py
+[[ $? == 0 ]] && echo " .. Test failed." && exit 0
+[[ $? == 127 ]] && echo " .. Test lacking a parameter." && exit 127
+
+echo " >> Assert that 5/10GB used is ok when max usage is 60%"
+MOCK_FREE_RAM=5000 MOCK_TOTAL_RAM=10000 MAX_RAM_PERCENTAGE=60 ../checks/free_ram.py
+[[ $? == 1 ]] && echo " .. Test failed." && exit 1
+[[ $? == 127 ]] && echo " .. Test lacking a parameter." && exit 127
+
+exit 0

app/checks/free_ram.py

@@ -0,0 +1,29 @@
+#!/usr/bin/env python3
+
+import re
+from os import environ
+from sys import stderr
+
+if 'MAX_RAM_PERCENTAGE' not in environ:
+    print("Missing MAX_RAM_PERCENTAGE parameter.\nUsage ./free_ram.py.", file=stderr)
+    exit(127)
+
+def check_ram(meminfopath, maxPercent):
+    meminfo = open(meminfopath).read()
+    memTotalreg = re.compile("MemTotal:\s+(\d+)")
+    memAvailreg = re.compile("MemAvailable:\s+(\d+)")
+    memTotal = float( memTotalreg.split(meminfo)[1] )
+    memAvail = float( memAvailreg.split(meminfo)[1] )
+    if "MOCK_FREE_RAM" in environ and "MOCK_TOTAL_RAM" in environ:
+        memAvail = float(environ["MOCK_FREE_RAM"]) * 1024
+        memTotal = float(environ["MOCK_TOTAL_RAM"]) * 1024
+    memUsed = memTotal - memAvail
+    memUsedPercent = memUsed/memTotal * 100
+    if memUsed/memTotal * 100 > maxPercent:
+        print("RAM usage too high: {0:.0f}MiB/{1:.0f}MiB ({2:.0f}% used, {3:.0f}MiB left. Max usage allowed: {4:.0f}% ({5:.0f}MiB)".format(memUsed/1024, memTotal/1024, memUsedPercent, memAvail/1024, maxPercent, maxPercent/100.0 * memTotal/1024 ))
+        return 1
+    print("RAM usage OK: {0:.0f}MiB/{1:.0f}MiB ({2:.0f}% used, {3:.0f}MiB left. Max usage allowed: {4:.0f}% ({5:.0f}MiB)".format(memUsed/1024, memTotal/1024, memUsedPercent, memAvail/1024, maxPercent, maxPercent/100.0 * memTotal/1024 ))
+    return 0
+
+
+exit(check_ram("/proc/meminfo", float(environ["MAX_RAM_PERCENTAGE"])))