Set sysctl values from Chef!

• node['sysctl'] - A namespace for sysctl settings.

There are two ways of setting sysctl values:

1. Set chef attributes in the sysctl namespace. e.g.:

    node.set['sysctl']['set swappiness'] = { 'vm.swappiness' => '20' }
   

2. Set values in a cookbook_file Resource.

3. With Ressource/Provider.

This Cookbook includes two LWRPs:

1. sysctl
2. sysctl_multi

• :save - Save and set a sysctl value (default).
• :set - Set a sysctl value.
• :remove - Remove a (previous set) sysctl.

• variable - Variable to manage. e.g. net.ipv4.ip_forward, vm.swappiness.
• value - Value to affect to variable. e.g. 1, 0.
• path - Path to a specific file.

###ruby

# Set 'vm.swappiness' to '60'. Will create /etc/sysctl.d/40-vm.wappiness.conf
sysctl 'vm.swappiness' do
    value '40'
end

####the same. will create /etc/sysctl.d/40-vm_swappiness_to_60.conf

sysctl 'vm swappiness to 60' do
  variable 'vm.swappiness'
  value '60'
end

####Remove /etc/sysctl.d/40-ip_config.conf sysctl 'ip config' do action :remove end

sysctl 'vm.swappiness' do
  action :set
  value '40'
end

• :save - Save and set a sysctl value (default).
• :set - set a sysctl value.
• :remove - remove a (previous set) sysctl.

• instructions - Hash with instruction. e.g. {variable => value, variable2 => value2}. Override use of 'variable' and 'value'.
• path - Path to a specific file.

####ruby

sysctl_multi 'ip config' do
  instructions {
    'net.ipv4.ip_forward' => '1',
    'net.ipv6.conf.all.forwarding' => '1',
    'net.ipv4.tcp_syncookies' => '1'}
end