kpm - Kernel Parameter Manager

What is this?

kpm (as the name suggests) is a program to manage kernel parameters. It reads target values from the environment and sets them if they do not match.

Why does this exist?

To run as a DaemonSet on a Kubernetes cluster, to enforce a set of target kernel parameters.

How do I get this majestic tool?

$ cargo install kpm

How do I use it?

For each managed Kernel Parameter, set an environment variable to the target value. The name of this variable should be the parameter name, prefixed with sysctl-.

env sysctl-fs.inotify.max_queued_events=16384 \
    sysctl-fs.inotify.max_user_instances=128 \
    sysctl-fs.inotify.max_user_watches=8192 \
    kpm enforce

By default, kpm only treats values that exactly match the target as "correct". This can be overridden by prefixing the value with one of the following identifiers:

Prefix	Rule	Description
==	EqualTo	Value must be exactly equal to the target.
=>	AtLeast	Value must be greater than or equal to the target.
=<	AtMost	Value must be less than or equal to the target.

These do not work with non-integer parameters. Since the vast majority of kernel parameters are integers, this is unlikely to be a problem. Use with string parameters will report false negatives, and set the value every time.

Environment Variables

Name	Default Value	Examples	Description
KPM_LOG_FILTER	info	error, warn, info, debug, trace.	Configures log filtering
KPM_LOG_STYLE	auto	auto, always, never.	Configures log styling

License

kpm is available under the MIT License, see LICENSE.txt for the full text.