Rapido helps you quickly test Linux kernel changes.

Quick Start

# install dracut and qemu, then...
git clone https://github.com/rapido-linux/rapido.git && cd rapido
./rapido cut simple-example # boot a throwaway VM using the host kernel

A demonstration screencast can be found here.

Setup

Clone this repository and install the following dependencies:

• Dracut:
  • Generates a VM image, with kernel-modules and minimal user-space
• QEMU:
  • Boots a given Dracut VM image and compiled Linux kernel on the local system
• systemd-networkd:
  • Configures networking within Rapido VMs (optional)
• iproute2:
  • Configures Bridge and TAP devices on the host (optional)

Rapido obtains all dependencies from the local system; no magic images or internet downloads are necessary. Individual cut scripts (e.g. cut/fstests_btrfs.sh) may require extra dependencies.

Rapido is primarily configured via rapido.conf. To boot a custom Linux kernel, copy rapido.conf.example and set the KERNEL_SRC parameter to the path of your compiled kernel source.

Network Configuration

Test VM images may be "cut" with or without network support. For networking, per-VM systemd-networkd configuration should be specified in the net-conf directory. An example is provided in net-conf.example. The rapido setup-network command should be run as root to configure a bridge network device and VM-assigned tap devices. By default, the bridge network is isolated, and isn't connected to any physical adapters.

Running

Depending on which kernel component or functionality you'd like to test, choose a cut script to generate a VM image. E.g.

./rapido cut fstests-btrfs

The cut script collects all required kernel modules and user-space dependencies from the local system and writes a VM initramfs image to initrds/myinitrd. Once generated, a VM using the image and kernel will boot immediately. Subsequent VMs can be booted manually via:

./rapido boot

Adding Your Own Tests

Rapido can be easily extended to test any kernel functionality of interest. Simply copy the cut/simple_example.sh and autorun/simple_example.sh scripts and modify them to suit your needs. The example scripts are fully annotated.

Feedback and Bug Reporting

Please raise any questions or issues upstream via https://github.com/rapido-linux/rapido/issues

Architecture