Images.md

Images

Minivirt maintains a database of images identified by their SHA256 checksum. They may have any number of tags.

Show images in the database:

% miv images
5446f671 1.4G ubuntu-22.04
84200bbd 115M alpine-3.15
8ad24d9f 1.4G ubuntu-20.04
c86a9115 114M alpine alpine-3.16

Building an image

Minivirt can build images from recipes, which are YAML files, with a syntax inspired by GitHub Actions workflows. Download any file from the /recipes directory and run:

miv build alpine-3.16.yaml --tag alpine -v

The -v flag directs the output of the build (serial console or SSH) to stdout.

The image is now in the database:

miv run alpine

Other image operations

Commit a VM as an image:

miv commit myvm myimage

Save the image as a TAR archive:

miv save myimage | gzip -1 > myimage.tgz

Later, load the image:

zcat myimage.tgz | miv load myimage

Database maintenance

To make sure the images and VMs are consistent, run a database check:

miv fsck

To remove an image, first untag it. This only removes the tag, not the image itself.

miv untag myimage

The image is removed during prune:

miv prune

Image repositories

Add a remote repository:

miv remote add default https://f003.backblazeb2.com/file/minivirt

Pull an image. {arch} will be interpolated to the machine architecture.

miv pull default alpine-{arch} alpine

To host an image repository, you need an object store (e.g. Amazon S3, Backblaze B2, MinIO, etc). Set the following environment variables:

• AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY: authentication credentials.
• AWS_ENDPOINT_URL (optional): if the object store is not hosted on the AWS public cloud, this should point to the appropriate endpoint.

The bucket name is taken from the last part of the remote's URL, e.g. minivirt for the default repository.

Run miv push to upload an image:

miv push default alpine-3.16 alpine-3.16-aarch64