A quick (hacky) Chef recipe for adding noatime and a swap file in case a swap file does not exist

chef-noatime-and-swap.rb

# Enable noatime on local ext3/4 & xfs filesystems

fstab = File.open('/etc/fstab',"r")
newlines = Array.new
needremount = Array.new
ihaveswap = false
fstab.each do |line|
  # Tokenize each fstab line with a space separator
  tokens = line.split
  if tokens[2] == "swap"
    newlines << tokens.join("\t")
    ihaveswap = true
    next
  elsif ((! %w{ ext3 ext4 xfs }.include?(tokens[2])) || (%w{ ext3 ext4 xfs tmpfs nfs auto }.include?(tokens[2]) && tokens[3].match(/noatime/)))
    newlines << tokens.join("\t")
    next
  end
  needremount << tokens[0]
  tokens[3] << ",noatime"
  newlines << tokens.join("\t")
end
fstab.close
newlines = newlines.compact.join("\n")
fstab = File.open("/etc/fstab", "w")
fstab.puts(newlines)
fstab.close

# Remount each mount point that got updated
needremount.each do |mountpoint|
  Chef::Log.info('Remounting #mountpoint')
  execute "mountpoint remout" do
    command "/bin/mount -o remount \"#{mountpoint}\""
    action :run
    timeout 30
  end
end

# Create a regular swap file in case there is none

if (ihaveswap == false)
  Chef::Log.info("Swapfile not found. Manually creating one of 512M for OOM safety")
  execute "creating swapfile" do
    command "/bin/dd if=/dev/zero of=/swap.img bs=1M count=512"
    action :run
    creates "/swap.img"
  end

  execute "formatting swapfile" do
    command "/sbin/mkswap -L local /swap.img"
    action :run
  end

  mount "none" do
    device "/swap.img"
    fstype "swap"
    options [ "sw"]
    dump 0
    pass 0
    action :enable
  end

  execute "mounting swapfile" do
    command "/sbin/swapon -a"
    action :run
  end

end

Very helpful. Thanks for this recipe!