sysrq

Go client to perform low-level commands via the Linux SysRq interface (accessible at /proc/sysrq-trigger).

Among other things, SysRq can crash the system by forcing a NULL pointer dereference, which makes it a good fit for Chaos Engineering experiments.

CLI

In addition to the Go library, there's a sysrq command-line tool you can install from source:

go get -u github.com/mlafeldt/sysrq/cmd/sysrq

Use the tool to trigger one or more commands:

sudo sysrq <cmd>...

This will print a list of all available commands:

sysrq -list

Vagrant playground

Here's how to run SysRq commands against a local Vagrant machine:

# Start Vagrant machine
vagrant up

# Trigger crash command
make trigger CMD=crash

# Show system logs
make log
...
ubuntu-xenial login: [   94.116848] sysrq: SysRq : Trigger a crash
[   94.152571] BUG: unable to handle kernel NULL pointer dereference at           (null)
[   94.263679] IP: [<ffffffff81504df6>] sysrq_handle_crash+0x16/0x20
...

# Fix Vagrant machine
vagrant reload

Docker

Since Docker mounts /proc/sysrq-trigger as read-only, you cannot run commands against other containers, but you can still affect the host system:

docker run --rm -v /proc/sysrq-trigger:/sysrq -e TRIGGER_FILE=/sysrq mlafeldt/sysrq <cmd>...

Author

This project is being developed by Mathias Lafeldt.