Psutil system resources library to scenarios/admin added

docs/scenarios/admin.rst

@@ -120,6 +120,60 @@ State files can be written using YAML, the Jinja2 template system or pure python
 
     `Salt Documentation <http://docs.saltstack.org/en/latest/index.html>`_
 
+
+Psutil
+------
+ `Psutil <https://code.google.com/p/psutil/>`_ is an interface to different system information (e.g. CPU, memory, disks, network, users and processes).
+
+Here is an example to be aware of some server overload. In case of some failed test (net, CPU) it send an email.
+
+.. code-block:: python
+
+    # Functions to get system values:
+    from psutil import cpu_percent, net_io_counters
+    # Functions to take a break:
+    from time import sleep
+    # Package for email services:
+    import smtplib
+    import string
+    MAX_NET_USAGE = 400000
+    MAX_ATTACKS = 4
+    attack = 0
+    counter = 0
+    while attack <= MAX_ATTACKS:
+        sleep(4)
+        counter = counter + 1
+        # Check the cpu usage
+        if cpu_percent(interval = 1) > 70:
+            attack = attack + 1
+        # Check the net usage
+        neti1 = net_io_counters()[1]
+        neto1 = net_io_counters()[0]
+        sleep(1)
+        neti2 = net_io_counters()[1]
+        neto2 = net_io_counters()[0]
+        # Calculate the bytes per second
+        net = ((neti2+neto2) - (neti1+neto1))/2
+        if net > MAX_NET_USAGE:
+            attack = attack + 1
+        if counter > 25:
+            attack = 0
+            counter = 0
+    # Write a very important email if attack is higher then 4
+    TO = "you@your_email.com"
+    FROM = "webmaster@your_domain.com"
+    SUBJECT = "Your domain is out of system resources!"
+    text = "Go and fix your server!"
+    BODY = string.join(("From: %s" %FROM,"To: %s" %TO,"Subject: %s" %SUBJECT, "",text), "\r\n")
+    server = smtplib.SMTP('127.0.0.1')
+    server.sendmail(FROM, [TO], BODY)
+    server.quit()
+
+
+A full terminal application like a widely extended top which is based on psutil and with the ability of a client-server
+monitoring is `glance <https://github.com/nicolargo/glances/>`_.
+
+
 Chef
 ----