#!/usr/bin/python -u
# ===========================================================================
#
# check_readonly - Check if all ext3 file systems are writable
#
# Usage: Simply run the script, and it will check the local host only.
#        There are no command-line options for this check.  Maybe in the
#        future, but for now, it does exactly what we want it to do.
#
# Changelog:
#
# 2008-06-05 -- bjared@ethosprime.com -- Created this script.
# ===========================================================================

import sys, os, re, commands

# Dictionary of Nagios Plug-in return-values
ERRORS={	'OK':0,
		'WARNING':1,
		'CRITICAL':2,
		'UNKNOWN':3,
		'DEPENDENT':4
};

# Initialize the return value
returnVal = ERRORS['OK']
# Initialize the return string
returnStr = "check_readonly OK: All mountpoints writable"

# Get a list of all the mounted volumes that are ext3
mounts = commands.getoutput("mount -t ext3").split("\n")

# Compile a regular expression to capture the mounted directories
myRE = re.compile("\S+ on (\S+) type ext3.*")

# Initialize the counter used within the "for" loop
counter = 1

# Loop through all the lines returned by the "mount -t ext3" command
for line in mounts:
	# Apply the regular expression, and return the captured value
	mountpoint = myRE.match(line).group(1)
	# Set wFile to the full path of our file we're going to test with
	wFile = mountpoint + "/this-is-only-a-test"
	try:
		# We see if we can open our file for writing in that partition
		wTest = file(wFile, "w")
	except:
		# If the write fails, we are dropped into here, and prepare output
		if counter == 1:
			returnVal = ERRORS['CRITICAL']
			returnStr = "check_readonly CRITICAL: Could not write to: "
		else:
			if counter > 1:
				returnStr += ", "
		returnStr += mountpoint
		counter += 1
	else:
		# If the write succeeded, and we clean up after ourselves.
		wTest.close()
		os.unlink(wFile)

# Print the status of this check
print returnStr

# Exit with our return value
sys.exit(returnVal)