vimto

vimto

vimto is a virtual machine testing orchestrator for the Go toolchain. It allows you to easily run Go unit tests using a specific Linux kernel.

# With .vimto.toml in place:
vimto -- go test .
# Otherwise:
vimto -kernel /path/to/vmlinuz -- go test .

The tests are executed inside an ephemeral VM, with an execution environment which mimics the host.

It's possible to obtain the kernel from a container image (requires Docker).

vimto -kernel example.org/reg/image:tag -- go test .

Finally, you can also use a path to a directory:

vimto -kernel /path/to/dir -- go test .

vimto expects the kernel to be at /boot/vmlinuz for containers and directories. See also Container format.

Installation

Install using the Go toolchain:

CGO_ENABLED=0 go install lmb.io/vimto@latest

Configuration

vimto reads a configuration file .vimto.toml in TOML format, either from the current directory or from the root of the git repository enclosing the current directory.

All available options and their values are in testdata/default.toml.

Currently not supported

• Networking
• Interactive shell sessions

Requirements

• An amd64 or arm64 host
• A recent version of qemu (8.1.3 is known to work)
• A Linux kernel with the necessary configuration (>= 4.9 is known to work)
• KVM (optional, see VIMTO_DISABLE_KVM)
• Docker (optional, to fetch kernels from OCI registries)

Here is a non-exhaustive list of required Linux options:

• CONFIG_9P_FS=y
• CONFIG_DEVTMPFS=y
• CONFIG_NET_9P_VIRTIO=y
• CONFIG_NET_9P=y
• CONFIG_NET_CORE=y
• CONFIG_OVERLAY_FS=y
• CONFIG_PCI=y
• CONFIG_SYSFS=y
• CONFIG_TMPFS=y
• CONFIG_TTY=y
• CONFIG_UNIX=y
• CONFIG_UNIX98_PTYS=y
• CONFIG_VIRTIO_CONSOLE=y
• CONFIG_VIRTIO_MMIO=y
• CONFIG_VIRTIO_NET=y
• CONFIG_VIRTIO_PCI=y
• CONFIG_VIRTIO=y
• CONFIG_VT=y