The TinyKVM VMOD processes data in Varnish at native performance using your servers CPU capabilities safely with sandboxing.

You can find the complete VMOD documentation here.

KVM_GID=$(getent group kvm | cut -d: -f3) docker compose up

The build dependencies for this VMOD can be found in CI, but briefly:

varnish-dev
libcurl4-openssl-dev
libpcre3-dev
libarchive-dev
libjemalloc-dev

This VMOD does not have an installation procedure. Simply build it from source, and copy the final libvmod_*.so into your VMOD folder (usually /usr/lib/varnish/vmods/):

./build.sh

Or manually:

# Create a .build folder and build the VMOD in it
mkdir -p .build
pushd .build
cmake .. -DCMAKE_BUILD_TYPE=Release -DVARNISH_PLUS=OFF
make -j6
popd

# Copy VMODs into Varnish VMOD folder
sudo cp .build/libvmod_*.so /usr/lib/varnish/vmods/

If during building you are seeing errors with a Python script, try setting the Python 3 executable directly using a CMake define:

cmake .. -DCMAKE_BUILD_TYPE=Release -DVARNISH_PLUS=OFF -DPython3_EXECUTABLE=$(which python3)

There is a build-merge-release CI system that currently only builds for Ubuntu 22.04:

Packages here.

vcl 4.1;
import tinykvm;
backend default none;

sub vcl_init {
	# Download and activate a Varnish-provided library of compute programs.
	# A full list of programs and how they can be used would be on the docs site.
	tinykvm.library("https://filebin.varnish-software.com/tinykvm_programs/compute.json");

	# Tell VMOD compute how to contact Varnish (Unix Socket *ONLY*)
	tinykvm.init_self_requests("/tmp/tinykvm.sock");
}

sub vcl_backend_fetch {
	# Fetch a JPG image from a remote server
	tinykvm.chain("fetch",
		"https://filebin.varnish-software.com/tinykvm_programs/spooky.jpg",
		"""{
			"headers": ["Host: filebin.varnish-software.com"]
		}""");
	# Transcode JPG to AVIF
	set bereq.backend = tinykvm.program("avif", "", """{
		"speed": 10,
		"quality": 35
	}""");
}

Programs and examples repository.

TinyKVM and VMOD-TinyKVM are released under a dual licensing model:

• Open Source License: GPL‑3.0 (see LICENSE).
• Commercial License: Available under terms controlled by Varnish Software.

For commercial licensing inquiries, please contact: compliance@varnish-software.com.

We welcome contributions! By submitting a pull request or other contribution, you agree to our Contributor License Agreement and our Code of Conduct.

For details on how to contribute, please refer to this document.