Create basic monit config files from /proc/mounts

mounts2monit.rb

#!/usr/bin/env ruby

# Linux only, sorry.
#
# Look for ext[34], xfs and vxfs. Alter the regexp FILESYSTEMS for others
#
# If you have /root as a separate partition, alter the value of ROOT_USABLE

# Config

FILESYSTEMS = /\b(ext\d|v?xfs)\b/
ROOT_USABLE = 'root'

#TARGET_DIR = '/etc/monit.d/filesystem'
TARGET_DIR = '/tmp/filesystem'
SUFFIX = '.conf'

TARGET_DIR_PERM = 0700
FILE_PERM = 0600

SPACE_PCT = 80
SPACE_FAILS = 5
SPACE_FAIL_PERIODS = 15
SPACE_SUCCESSES = 5

INODE_PCT = 80
INODE_FAILS = 5
INODE_FAIL_PERIODS = 15
INODE_SUCCESSES = 5

GROUP = "disk-resource"

# Not really config - just as it is on UNIX
ROOT_PATH = '/'

# Return true iff at then end name exists, is a directory
# and we own it, with the right perms
# Yes, race conditions exist.

def safe_mkdir( name, perm )
  if Dir.exists? name
    begin
      File.chmod( perm, name )
    rescue
      $stderr.puts "#{name} can not be set to perms #{perm}"
      return false
    end
  else
    if File.exists? name
      $stderr.puts "#{name} exists and is a file. Bailing"
      return false
    end
    begin
      Dir.mkdir( name, perm )
    rescue
      $stderr.puts "#{name} could not be created. Bailing"
      return false
    end
  end
  return File.owned? name
end

exit unless safe_mkdir( TARGET_DIR, TARGET_DIR_PERM )

File.open('/proc/mounts').each do |line|
  if line =~ FILESYSTEMS
    components = line.split
    device = components[0]
    path = components[1]

    usable_path = ( path == ROOT_PATH ) ? ROOT_USABLE : path[1..-1].gsub(/\//,'_')
    puts usable_path
    File.open( File.join( TARGET_DIR , "#{usable_path}#{SUFFIX}" ), File::WRONLY|File::TRUNC|File::CREAT, FILE_PERM ) do |file|
      file.print <<-eos
check filesystem #{usable_path} path #{device}
    group #{GROUP}
    if space > #{SPACE_PCT}% #{SPACE_FAILS} times #{SPACE_FAIL_PERIODS} cycles then alert
        else if succeeded #{SPACE_SUCCESSES} cycles then alert
    if inode > #{INODE_PCT}% #{INODE_FAILS} times #{INODE_FAIL_PERIODS} cycles then alert
        else if succeeded #{INODE_SUCCESSES} cycles then alert
    eos
    end
  end
end