7e8295189b
In case the `GOOGLE_APPLICATION_CREDENTIALS` environment variable is not set, a redirect to storage.googleapis.com is issued, which means the underlying bucket objects need to be publicly accessible. This wasn't really obvious until now, so further clarify it.
148 lines
5.7 KiB
Markdown
148 lines
5.7 KiB
Markdown
<div align="center">
|
|
<img src="docs/src/nixery-logo.png">
|
|
</div>
|
|
|
|
-----------------
|
|
|
|
[](https://travis-ci.org/google/nixery)
|
|
|
|
**Nixery** is a Docker-compatible container registry that is capable of
|
|
transparently building and serving container images using [Nix][].
|
|
|
|
Images are built on-demand based on the *image name*. Every package that the
|
|
user intends to include in the image is specified as a path component of the
|
|
image name.
|
|
|
|
The path components refer to top-level keys in `nixpkgs` and are used to build a
|
|
container image using a [layering strategy][] that optimises for caching popular
|
|
and/or large dependencies.
|
|
|
|
A public instance as well as additional documentation is available at
|
|
[nixery.dev][public].
|
|
|
|
You can watch the NixCon 2019 [talk about
|
|
Nixery](https://www.youtube.com/watch?v=pOI9H4oeXqA) for more information about
|
|
the project and its use-cases.
|
|
|
|
This is not an officially supported Google project.
|
|
|
|
## Demo
|
|
|
|
Click the image to see an example in which an image containing an interactive
|
|
shell and GNU `hello` is downloaded.
|
|
|
|
[](https://asciinema.org/a/262583?autoplay=1)
|
|
|
|
To try it yourself, head to [nixery.dev][public]!
|
|
|
|
The special meta-package `shell` provides an image base with many core
|
|
components (such as `bash` and `coreutils`) that users commonly expect in
|
|
interactive images.
|
|
|
|
## Feature overview
|
|
|
|
* Serve container images on-demand using image names as content specifications
|
|
|
|
Specify package names as path components and Nixery will create images, using
|
|
the most efficient caching strategy it can to share data between different
|
|
images.
|
|
|
|
* Use private package sets from various sources
|
|
|
|
In addition to building images from the publicly available Nix/NixOS channels,
|
|
a private Nixery instance can be configured to serve images built from a
|
|
package set hosted in a custom git repository or filesystem path.
|
|
|
|
When using this feature with custom git repositories, Nixery will forward the
|
|
specified image tags as git references.
|
|
|
|
For example, if a company used a custom repository overlaying their packages
|
|
on the Nix package set, images could be built from a git tag `release-v2`:
|
|
|
|
`docker pull nixery.thecompany.website/custom-service:release-v2`
|
|
|
|
* Efficient serving of image layers from Google Cloud Storage
|
|
|
|
After building an image, Nixery stores all of its layers in a GCS bucket and
|
|
forwards requests to retrieve layers to the bucket. This enables efficient
|
|
serving of layers, as well as sharing of image layers between redundant
|
|
instances.
|
|
|
|
## Configuration
|
|
|
|
Nixery supports the following configuration options, provided via environment
|
|
variables:
|
|
|
|
* `PORT`: HTTP port on which Nixery should listen
|
|
* `NIXERY_CHANNEL`: The name of a Nix/NixOS channel to use for building
|
|
* `NIXERY_PKGS_REPO`: URL of a git repository containing a package set (uses
|
|
locally configured SSH/git credentials)
|
|
* `NIXERY_PKGS_PATH`: A local filesystem path containing a Nix package set to
|
|
use for building
|
|
* `NIXERY_STORAGE_BACKEND`: The type of backend storage to use, currently
|
|
supported values are `gcs` (Google Cloud Storage) and `filesystem`.
|
|
|
|
For each of these additional backend configuration is necessary, see the
|
|
[storage section](#storage) for details.
|
|
* `NIX_TIMEOUT`: Number of seconds that any Nix builder is allowed to run
|
|
(defaults to 60)
|
|
* `NIX_POPULARITY_URL`: URL to a file containing popularity data for
|
|
the package set (see `popcount/`)
|
|
|
|
If the `GOOGLE_APPLICATION_CREDENTIALS` environment variable is set to a service
|
|
account key, Nixery will also use this key to create [signed URLs][] for layers
|
|
in the storage bucket. This makes it possible to serve layers from a bucket
|
|
without having to make them publicly available.
|
|
|
|
In case the `GOOGLE_APPLICATION_CREDENTIALS` environment variable is not set, a
|
|
redirect to storage.googleapis.com is issued, which means the underlying bucket
|
|
objects need to be publicly accessible.
|
|
|
|
### Storage
|
|
|
|
Nixery supports multiple different storage backends in which its build cache and
|
|
image layers are kept, and from which they are served.
|
|
|
|
Currently the available storage backends are Google Cloud Storage and the local
|
|
file system.
|
|
|
|
In the GCS case, images are served by redirecting clients to the storage bucket.
|
|
Layers stored on the filesystem are served straight from the local disk.
|
|
|
|
These extra configuration variables must be set to configure storage backends:
|
|
|
|
* `GCS_BUCKET`: Name of the Google Cloud Storage bucket to use (**required** for
|
|
`gcs`)
|
|
* `GOOGLE_APPLICATION_CREDENTIALS`: Path to a GCP service account JSON key
|
|
(**optional** for `gcs`)
|
|
* `STORAGE_PATH`: Path to a folder in which to store and from which to serve
|
|
data (**required** for `filesystem`)
|
|
|
|
### Background
|
|
|
|
The project started out inspired by the [buildLayeredImage][] blog post with the
|
|
intention of becoming a Kubernetes controller that can serve declarative image
|
|
specifications specified in CRDs as container images. The design for this was
|
|
outlined in [a public gist][gist].
|
|
|
|
## Roadmap
|
|
|
|
### Kubernetes integration
|
|
|
|
It should be trivial to deploy Nixery inside of a Kubernetes cluster with
|
|
correct caching behaviour, addressing and so on.
|
|
|
|
See [issue #4](https://github.com/google/nixery/issues/4).
|
|
|
|
### Nix-native builder
|
|
|
|
The image building and layering functionality of Nixery will be extracted into a
|
|
separate Nix function, which will make it possible to build images directly in
|
|
Nix builds.
|
|
|
|
[Nix]: https://nixos.org/
|
|
[layering strategy]: https://storage.googleapis.com/nixdoc/nixery-layers.html
|
|
[gist]: https://gist.github.com/tazjin/08f3d37073b3590aacac424303e6f745
|
|
[buildLayeredImage]: https://grahamc.com/blog/nix-and-layered-docker-images
|
|
[public]: https://nixery.dev
|
|
[gcs]: https://cloud.google.com/storage/
|