sysctl

Role for handling /etc/sysctl.d/*.conf files. Applies new sysctl setting on run.

Version

• 3.0.0 --- Add Unsible-core 2.16. Removed support for Ubuntu xenial and bionic
• 2.2.0 --- Add Ubuntu 24.04 noble support
• 2.1.2 --- Allow Fedora CoreOS 39
• 2.1.1 --- bug fix, ansible-lint
• 2.1.0 --- add Fedora CoreOS support
• 2.0.0 --- updated for ansible 2.12.9
• 1.5.0 --- add RHEL9 and CentOS Stream 8 support
• 1.4.0 --- add jammy support; remove centos8 support
• 1.3.0 --- add rhel8 support; remove trusty and centos6 support
• 1.2.0 --- remove ubuntu precise from testing
• 1.1.0 --- added ubuntu focal, 20.04
• 1.0.2 --- tested with Ansible 2.9.11
• 1.0.1 --- prepare for github
• 1.0.0 --- initial role
• master --- latest development version

Requirements

This role is limited to

• Ubuntu 24.04 - Noble
• Ubuntu 22.04 - Jammy
• Ubuntu 20.04 - Focal
• CentOS 7
• CentOS Stream 8
• RHEL 8
• RHEL 9
• Fedora CoreOS 38
• Fedora CoreOS 39

Role Variables

• sysctl_d --- nested dictionary, key is filename in /etc/sysctl.d, value is dictionary with sysctl key and values, default {}
• sysctl_exclusive --- remove foreign files in /etc/sysctl.d - require reboot, default false

Dependencies

None.

Example Playbook

Example variables is optimized 10G <100ms network. Enable qdisk fq on servers, fq_codel on routers, ie. VM hosts. Not enabled in example since this role should work on legacy OSes.

- hosts: servers
  roles:
     - role: sysctl
       sysctl_d:
         50-network-100ms.conf:
           net.core.rmem_max: 67108864
           net.core.wmem_max: 67108864
           net.ipv4.tcp_rmem: 4096 87380 33554432
           net.ipv4.tcp_wmem: 4096 87380 33554432
           net.ipv4.tcp_mtu_probing: 1
           #net.core.default_qdisc: fq
        60-fast-start.conf:
           net.ipv4.tcp_slow_start_after_idle: 0

Testing

NOTICE: Fedora CoreOS is tested manually, but currently no automatic tests are added for FCOS.

Test environment for all OSes

cd tests
vagrant up

Rerun role

Run role on all OSes again.

vagrant provision

Debug interactively

This uses cluster ssh to work with all vagrant boxes at the same time.

vagrant ssh-config > ~/.ssh/config
cat ~/.ssh/config | grep ^Host | cut -d\  -f2 | xargs cssh

License

GPLv2

Author Information

Created 2020 by IT Infrastructure at MET Norway

Contactpoint: IT Infrastructure Basis Team

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