From 076f515e6db786e11de243d916574378da779dcf Mon Sep 17 00:00:00 2001
From: Lopaka Delp <lopaka@rightscale.com>
Date: Tue, 23 Aug 2011 13:41:41 -0700
Subject: [PATCH] [sys::setup_swap] move more processing to chef resources. RS
 standard on comments. using mount resource to edit /etc/fstab

---
 recipes/setup_swap.rb | 92 +++++++++++++++----------------------------
 1 file changed, 32 insertions(+), 60 deletions(-)

diff --git a/recipes/setup_swap.rb b/recipes/setup_swap.rb
index dc61ada..eb997e1 100644
--- a/recipes/setup_swap.rb
+++ b/recipes/setup_swap.rb
@@ -34,52 +34,34 @@
 
 def clean_swap(swap_file)
 
-  # turn off swap on swap_file if turned on
-  if ( File.open('/proc/swaps').grep(/^#{swap_file}\b/).any? )
-    script 'deactivate swapfile' do
-      interpreter 'bash'
-      code <<-eof
-        swapoff #{swap_file}
-      eof
-    end
+  # Turn off swap on swap_file if turned on
+  bash 'deactivate swapfile' do
+    only_if { File.open('/proc/swaps').grep(/^#{swap_file}\b/).any? }
+    code <<-eof
+      swapoff #{swap_file}
+    eof
   end
 
-  # remove swap from /etc/fstab
-  if ( File.open('/etc/fstab').grep(/^\s*#{swap_file}\b/).any? )
-    new_fstab_contents = ""
-    fstab_contents = File.open('/etc/fstab') { |f| f.read }
-    fstab_contents.each_line do |line| 
-      if ( line.strip =~ /^#{swap_file}\b/ )
-        # skipping
-      else
-        new_fstab_contents << line
-      end
-    end
-    file "/etc/fstab" do
-      content new_fstab_contents
-      owner "root"
-      group "root"
-      mode "0644"
-      action :create
-    end
+  # Remove swap from /etc/fstab
+  mount '/dev/null' do
+    action :disable
+    device "#{swap_file}"
   end
 
-  # delete swap_file if it exists
-  if ( File.exists?(swap_file) )
-    file "#{swap_file}" do
-      backup false
-      action :delete
-    end
+  # Delete swap_file if it exists
+  file "#{swap_file}" do
+    only_if {File.exists?(swap_file)}
+    backup false
+    action :delete
   end
 
 end
 
 def create_swap(swap_file, swap_size)
 
-  # create swapfile, set it as swap, and turn swap on
-  script 'create swapfile' do
-    not_if {File.exists?(swap_file)}
-    interpreter 'bash'
+  # Create swapfile, set it as swap, and turn swap on
+  bash 'create swapfile' do
+    not_if { File.exists?(swap_file) }
     code <<-eof
       dd if=/dev/zero of=#{swap_file} bs=1M count=#{swap_size}
       chmod 600 #{swap_file}
@@ -88,38 +70,29 @@ def create_swap(swap_file, swap_size)
     eof
   end
   
-  # append swap to /etc/fstab if not already there
-  if ( File.open('/etc/fstab').grep(/^\s*#{swap_file}\b/).any? )
-    log "#{swapfile} already in /etc/fstab"
-  else
-    fstab_contents = File.open('/etc/fstab') { |f| f.read }
-    fstab_contents << "#{swap_file}  swap      swap    defaults        0 0\n"
-    file "/etc/fstab" do
-      content fstab_contents
-      owner "root"
-      group "root"
-      mode "0644"
-      action :create
-    end
+  # add swap to /etc/fstab 
+  mount '/dev/null' do
+    action :enable
+    device "#{swap_file}"
+    fstype 'swap'
   end
+
 end
 
-# sanitize user data 'swap_size'
+# Sanitize user data 'swap_size'
 if ( swap_size !~ /^\d*[.]?\d+$/ )
-  log "invalid swap size '#{swap_size}' - raising error"
   raise "ERROR: invalid swap size."
 else
-  # convert swap_size from GB to MB
+  # Convert swap_size from GB to MB
   swap_size = ((swap_size.to_f)*1024).to_i
 end
 
-# sanitize user data 'swap_file'
+# Sanitize user data 'swap_file'
 if (swap_file !~ /^\/{1}(((\/{1}\.{1})?[a-zA-Z0-9 ]+\/?)+(\.{1}[a-zA-Z0-9]{2,4})?)$/ )
-  log "invalid swap file name - raising error"
   raise "ERROR: invalid swap file name"
 end
 
-# skip creating swap or disable swap
+# Skip creating swap or disable swap
 if (swap_size == 0)
   if ( File.exists?(swap_file) && File.open('/proc/swaps').grep(/^#{swap_file}\b/).any? )
     clean_swap(swap_file)
@@ -128,26 +101,25 @@ def create_swap(swap_file, swap_size)
   end
 else
 
-  # for idempotency, check if selected swapfle is in place, correct size, and on
+  # For idempotency, check if selected swapfle is in place, it's correct size, and it's on
   if ( File.exists?(swap_file) && \
        File.stat(swap_file).size/1048576 == swap_size && \
        File.open('/proc/swaps').grep(/^#{swap_file}\b/).any? )
     log "valid current swap config"
   else
-    # check for remnents of swap
+    # Check for remnents of swap
     if ( File.exists?(swap_file) || File.open('/proc/swaps').grep(/^#{swap_file}\b/).any? )
       log "swap remnents detected - cleaning"
       clean_swap(swap_file)
     end
 
-    # determine if swapfile is too big for fs that holds it
+    # Determine if swapfile is too big for fs that holds it
     (fs_total,fs_used) = `df --block-size=1M -P #{File.dirname(swap_file)} |tail -1| awk '{print $2":"$3}'`.split(":")
     if ( (((fs_used.to_f + swap_size).to_f/fs_total.to_f)*100).to_i >= fs_size_threshold_percent )
-      log "swap file size would exceed filesystem threshold of #{fs_size_threshold_percent} percent - raising error"
       raise "ERROR: swap file size too big - would exceed #{fs_size_threshold_percent} percent of filesystem"
     end
 
-    # should now setup swap file
+    # Should now setup swap file
     create_swap(swap_file,swap_size)
   end
 end