Recipes

#
# Cookbook:: zram
# Recipe:: default
#

org = node['org_namespace']

# Set swap size in MB. By default it sets it to 10% of the total memory.
node.default[org]['zram']['swap_size_mb'] = (node['memory']['total'].to_i / node[org]['zram']['percent_of_memory']) / 1024

# Set number of devices equal to the number of cores.
node.default[org]['zram']['num_devices'] = node['cpu']['cores']

# Set the size of each device based on the full size devided by the number of devices.
(1..node[org]['zram']['num_devices'].to_i).each do |n|
  node.default[org]['zram']['disk_size']["zram#{n - 1}"] = node[org]['zram']['swap_size_mb'].to_i / node[org]['zram']['num_devices'].to_i
end

template 'modules-load_zram.conf' do
  path '/etc/modules-load.d/zram.conf'
  source 'modules-load_zram.conf.erb'
  user 'root'
  group 'root'
  mode '0640'
  action :create
end

template 'modeprobe_zram.conf' do
  path '/etc/modprobe.d/zram.conf'
  source 'modeprobe_zram.conf.erb'
  user 'root'
  group 'root'
  mode '0640'
  action :create
  notifies :stop, 'systemd_unit[zram.service]', :immediately if ::File.exist?('/etc/systemd/system/zram.service')
  notifies :unload, 'kernel_module[zram]', :immediately unless node[org]['test_kitchen'] || !shell_out('modinfo zram')
end

template '99-zram.rules' do
  path '/etc/udev/rules.d/99-zram.rules'
  source '99-zram.rules.erb'
  user 'root'
  group 'root'
  mode '0640'
  action :create
  notifies :stop, 'systemd_unit[zram.service]', :immediately if ::File.exist?('/etc/systemd/system/zram.service')
  notifies :unload, 'kernel_module[zram]', :immediately unless node[org]['test_kitchen'] || !shell_out('modinfo zram')
end

# Loading zram modules.
# Not loading it in test_kitchen on the chance the host system already has it enabled.
unless node[org]['test_kitchen']
  kernel_module 'zram' do
    action :load
  end
end

# Creating zram service.
systemd_unit 'zram.service' do
  content({ Unit: {
            Description: 'zram',
            After: 'multi-user.target',
          },
          Service: {
            Type: 'oneshot',
            RemainAfterExit: 'true',
            ExecStartPre: node[org]['zram']['disk_size'].keys.collect { |k| "/sbin/mkswap /dev/#{k}" },
            ExecStart: node[org]['zram']['disk_size'].keys.collect { |k| "/sbin/swapon -p 100 /dev/#{k}" },
            ExecStop: node[org]['zram']['disk_size'].keys.collect { |k| "/sbin/swapoff /dev/#{k}" },
          },
          Install: {
            WantedBy: 'multi-user.target',
          } })
  if node[org]['test_kitchen']
    action [:create, :enable]
  else
    action [:create, :enable, :start]
  end
end

# Setting sysctl params.
node[org]['zram']['sysctl']['params'].each do |k, v|
  sysctl k do
    value v
  end
end

#
# Cookbook:: zram
# Recipe:: uninstall
#
# Copyright:: 2021, The Authors, All Rights Reserved.

org = node['org_namespace']

# Set number of devices equal to the number of cores.
node.default[org]['zram']['num_devices'] = node['cpu']['cores']

# Set the size of each device based on the full size divided by the number of devices.
(1..node[org]['zram']['num_devices'].to_i).each do |n|
  swap_file "/dev/zram#{n - 1}" do
    action :remove
  end
end

unless node[org]['test_kitchen']
  kernel_module 'zram' do
    action :unload
  end
end

%w(
  /etc/modules-load.d/zram.conf
  /etc/modprobe.d/zram.conf
  /etc/udev/rules.d/99-zram.rules
).each do |cleanup_files|
  file cleanup_files do
    action :delete
  end
end

# Creating zram service.
systemd_unit 'zram.service' do
  action [:stop, :delete]
end