sysctl

Table of Contents

1. Description
2. Setup
   • What sysctl affects
   • Setup requirements
   • Beginning with sysctl
3. Usage
4. Limitations

Description

[sysctl] is used to modify kernel parameters at runtime. The parameters available on Linux are those listed under /proc/sys/. Procfs is required for sysctl support in Linux.

This module supports setting parameter values that are persistent across reboots by managing the system [sysctl] configuration files.

sysctl::variable resource declares the "private" resource, sysctl::define, which is exported and eventually collected by the sysctl class.

Setup

What sysctl affects

• /etc/sysctl.conf
• /etc/sysctl.d/*.conf
• optionally execute sysctl at runtime to enforce values

Beginning with sysctl

To make use of the sysctl::variable resource, the sysctl class must be included in your puppet manifest.

include sysctl

Usage

Manage a parameter with a resource:

sysctl::variable { 'net.ipv4.ip_forward':
  ensure => '1',
}

Manage multiple parameters with hiera:

sysctl::variable:
  net.ipv4.ip_forward:
    ensure: 1
  net.ipv6.bindv6only:
    ensure: 1
    enforce: false
  net.ipv4.tcp_congestion_control:
    ensure: absent
  net.core.somaxconn:
    ensure: 65535
    comment: increased to accommodate traffic handling requirements

Separate multi-value variables with a single space:

sysctl::variable { 'net.ipv4.tcp_rmem':
  ensure => '4096 65536 16777216',
}

Remove the sysctl configuration for a variable:

sysctl::variable { 'vm.swappiness':
  ensure => absent,
}

Ensure variables are set in a consistent order using the prefix parameter:

sysctl::variable { 'net.ipv4.ip_forward':
  ensure => '1',
  prefix => '60',
}

Limitations

Testing! Could use many more unit tests.

Credit

Inspired by Matthias Saou's thias/puppet-sysctl module.

Reference

Table of Contents

Classes

• sysctl

Defined types

Public Defined types

• sysctl::variable: manage a kernel variable with sysctl

Private Defined types

• sysctl::define: collected resource to manage a variable

Classes

sysctl

The sysctl class.

Examples

include sysctl

Parameters

The following parameters are available in the sysctl class:

• variable
• purge
• symlink99
• binary
• use_dir
• conf_dir
• owner
• group
• mode

variable

Data type: Variant[Hash,Undef]

hash of variables to set, typically defined in hiera

purge

Data type: Boolean

purge conf_dir of any non-puppet managed files

symlink99

Data type: Boolean

symlink sysctl.conf to conf_dir/99-sysctl.conf

binary

Data type: Stdlib::Absolutepath

full path of sysctl executable

use_dir

Data type: Boolean

manage per-variable files in conf_dir

conf_dir

Data type: Stdlib::Absolutepath

full path to sysctl conf.d directory

owner

Data type: Variant[String,Integer,Undef]

set file owner

group

Data type: Variant[String,Integer,Undef]

set file group

mode

Data type: Variant[String,Undef]

set file mode

Defined types

sysctl::variable

manage a kernel variable with sysctl

Parameters

The following parameters are available in the sysctl::variable defined type:

• variable
• ensure
• prefix
• suffix
• content
• source
• enforce
• comment

variable

Data type: Optional[String]

kernel variable to manage, defaults to the resource title

Default value: $title

ensure

Data type: Variant[String,Integer,Undef]

value to assign, use absent or undef to remove

Default value: undef

prefix

Data type: Optional[String]

prefix to conf.d variable filename

Default value: undef

suffix

Data type: String

suffix to conf.d variable filename

Default value: '.conf'

content

Data type: Optional[String]

set value from content instead of ensure not supported if use_dir is disabled

Default value: undef

source

Data type: Optional[String]

set value from a source instead of ensure not supported if use_dir is disabled

Default value: undef

enforce

Data type: Boolean

ensure value is set at puppet runtime

Default value: true

comment

Data type: Optional[Variant[String,Array[String]]]

comment to add to file

Default value: undef

Changelog

All notable changes to this project will be documented in this file.

Release 0.6.0

• Add Puppet 8 support
• Drop Puppet < 7

Release 0.5.2

• Initial public release

Notes

Inspired by Matthias Saou's [thias/puppet-sysctl] module.