# kontain.me

[![CI](https://github.com/imjasonh/kontain.me/actions/workflows/ci.yaml/badge.svg?event=push)](https://github.com/imjasonh/kontain.me/actions/workflows/ci.yaml)
[![Deploy](https://github.com/imjasonh/kontain.me/actions/workflows/deploy.yaml/badge.svg)](https://github.com/imjasonh/kontain.me/actions/workflows/deploy.yaml)

Serving container images generated on-demand, at the time they are requested.

These include:

* [`random.kontain.me`](./cmd/random), which serves randomly-generated images.
  - [browse](https://oci.dag.dev/?image=random.kontain.me/random)
* [`mirror.kontain.me`](./cmd/mirror), which pulls and caches images from other registries.
  - [browse](https://oci.dag.dev/?image=mirror.kontain.me/busybox)
* [`flatten.kontain.me`](./cmd/flatten), which pulls and flattens images from other registries,
  so they contain only one layer.
  - [browse](https://oci.dag.dev/?image=flatten.kontain.me/cgr.dev/chainguard/go)
* [`ko.kontain.me`](./cmd/ko), which builds a Go binary into a container image using
  [`ko`](https://github.com/google/ko).
  - [browse](https://oci.dag.dev/?image=ko.kontain.me/github.com/ko-build/ko/test)
* [`apko.kontain.me`](./cmd/apko), which builds a minimal base image containing
  APK packages, using [`apko`](https://apko.dev).
  - [browse](https://oci.dag.dev/?image=apko.kontain.me/kubectl)
* [`git.kontain.me`](./cmd/git), which serves an image containing a shallow
  clone of a Git repo at a given branch, tag, or commit, using
  [`go-git`](https://github.com/go-git/go-git).
  - [browse](https://oci.dag.dev/?image=git.kontain.me/github.com/imjasonh/kontain.me)

This repo also serves a few non-registry oddities:

* [`viz.kontain.me`](./cmd/viz) visualizes shared image layers using
  [Graphviz](https://graphviz.org/).
* [`infinite-git.kontain.me`](./cmd/infinite-git) is a Git HTTP server that
  generates a new commit every time the repo is pulled.
* [`infinite-go.kontain.me`](./cmd/infinite-go) is a Go module that generates
  a new module version every time it's fetched.

# Caveats

* The registry does not accept pushes.
* This is a silly hack and probably isn't stable. Don't rely on it for anything
  serious.
* It could probably do a lot of smart things to be a lot faster. 🤷
* Blobs and manifests are cached for 24 hours wherever possible, but will be
  rebuilt from scratch after that time.

# How it works

The service is built on [Google Cloud Run](https://cloud.google.com/run).

When the service receives a request for an image manifest, it parses the
request and generates layers for the requested image, writing the manifest and
blobs to [Google Cloud Storage](https://cloud.google.com/storage/). After it
receives the manifest, `docker pull` fetches the blobs. The app simply
redirects to Cloud Storage to serve manifests and blobs.