created_at2023-06-17 16:09:15.158581
updated_at2023-06-18 20:27:21.568985
descriptionTool used to build gvmi images used by Golem Network. Companion app to Golem Registry




Golem VM Image builder used as companion app for Golem Registry: https://registry.golem.network


Running docker engine is required. Tool supports Linux, Windows and macOS. Note that when using macOS ARM version use --platform linux/amd64 option for docker builds.


You can install gvmkit-build using pip (python3 with pip installer is required)

pip install gvmkit-build

or install form npm (npm installation is required)

npm install -g gvmkit-build

or install using cargo (Rust toolchain is required, a bit slow because it compiles from sources)

cargo install gvmkit-build

or download prebuild from github releases page:


or build from sources, you can find binary in target/release/gvmkit-build (or gvmkit-build.exe on Windows)

cargo build --release


Golem Network is using gvmi images as base for creating VMs for tasks. These images are basically squashfs images with some additional metadata. They can be prepared from docker images using this (gvmkit-build) tool.

Naming image

The tool as main argument is taking docker image name.

Docker Image id is composed maximum of three parts: <username>/<image_name>:tag It can be also for example <image_name> (tag is defaulting to latest)

Following command will build image and create *.gvmi file in current directory

gvmkit-build <docker_image_id>

If image not exist locally the tool is trying to pull it from docker hub.

To successfully add image to registry portal you have to name image accordingly or use

gvmkit-build <user_name>/<image_name>:<tag> --push

or if your local image name is not compatible use

gvmkit-build <docker_image_id> --push-to <user_name>/<image_name>:<tag>

Build process explained a bit

Tool is creating new container and is copying data from given image to new container. After copying is finished mksquashfs command is used inside tool container to create squashfs image. After adding metadata *.gvmi file is created and tool container removed. Note that tool image will stay downloaded on your machine for future use (it is quite small so no worry about disk space)

[Optional] - building squashfs-tools image

If you want to use your own tool without pulling from dockerhub: Go to squashfs-tools directory and run

docker build . -t my_squash_fs_builder

add environment variable to .env in folder where you run gvmkit-build


For managing docker images and containers bollard library is used. https://docs.rs/bollard/latest/bollard/

Troubleshooting login to registry portal

The tool is using https://registry.golem.network as default registry portal. You can change this behaviour by setting REGISTRY_URL environment variable. You should create account on registry portal and generate access token for your user. If you really don't want to create account you can use anonymous upload (see section below about anonymous upload).

The tool will ask for login when --login --push or --push-to option is specified.

For storing login information rpassword library is used: https://docs.rs/crate/rpassword/latest

Only one instance of login/token is kept saved at "gvmkit-build-rs/default". So if you login with new user/token old pair will be forgotten.

This option will ask for login to registry portal

gvmkit-build --login

You can use command for check if your login information is correct

gvmkit-build --login-check 

If you want to forget your login information you can use, it will clear your login information

gvmkit-build --logout 

Above command are optional, because you will be asked for login automatically if you use --push or --push-to option.

On some systems when no secure store is provided you will be forced to use following method of keeping login/token pair. You can optionally put them in .env file from convenience in your working directory. Remember to set proper permissions to the file (chmod 600 .env) if using on shared machine.


When REGISTRY_USER/REGISTRY_TOKEN is set in environment variables, secure rpassword storage won't be used.

Uploading to multiple tags

The tool cannot upload to multiple tags, but you can call it multiple times with different tags. All steps of operations are cached so no worry about re-uploading same file multiple times.

Uploading large files

The tool is using chunked upload with default chunk size 10MB (changing not recommended). Four upload workers are created by default (you can increase/decrease number of workers using --upload-workers argument depending on your network conditions). If you think your upload is stuck you can always stop and run tool again to finish download. Only chunks that were not uploaded will be uploaded again.

Note: Total limit of chunks is set to 1000 (so 10GB by default). If you want to upload larger file you have to set greater chunk size accordingly.

Uploading image without login

You can upload images anonymously. Note that lifetime of such images is limited, and they can be removed from registry portal after some time without notice

cargo run --release -- <image_name> --push --nologin

Uploading image without building part

If you are sure that you have proper *.gvmi file for example my-test.gvmi you can use

gvmkit-build --direct-file-upload my-test.gvmi --push-to <user_name><image_name>/<tag>

or anonymously

gvmkit-build --direct-file-upload my-test.gvmi --push --nologin

Changing squashfs options when creating image

You can change compression used in mksquashfs to produce more or less compact images.

Look for help for more information. Note that currently zstd is not supported by Golem Network (you can use xz instead for extra compact images).

gvmkit-build --help
Commit count: 148

cargo fmt