nushell/docs/docker.md

Docker Guide

tag	base image	plugins	package manager	libs & bins	size
latest, debian	debian:latest	yes	apt	a lot, including glibc	~(48+62) MB
slim	debian:stable-slim	yes	apt	all nu:debian image but exclude this list	~(26+62) MB
alpine	alpine:latest	yes	apk	all nu:musl-busybox image + libcrypto, libssl, libtls, libz	~(3+61) MB
musl-busybox	busybox:musl	no	—	GNU utils + musl	~(1+16) MB
glibc-busybox	busybox:glibc	no	—	GNU utils + glibc	~(3+17) MB
musl-distroless	distroless/static	no	—	see here	~(2+16) MB
glibc-distroless	distroless/base	no	—	distroless/static with glibc	~(17+17) MB
glibc	scratch	no	—	only nu binary-executable which depend on glibc runtime	~17 MB
musl	scratch	no	—	only nu binary-executable statically linked to musl	~16 MB

Image Variants

nu:<version>

This is the defacto image. If you are unsure about what your needs are, you probably want to use this one. It is designed to be used both as a throw away container (mount your source code and start the container to start your app), as well as the base to build other images off of.

example

Let say you create a plugin in Rust.

• create a Dockerfile in your root project

FROM nu:0.2

COPY /target/debug/nu_plugin_cowsay /bin/
ENTRYPOINT ["nu"]

• build your project first then run it via docker

cargo build
docker run -it .

nu:<version>-slim

This image does not contain the common packages contained in the default tag and only contains the minimal packages needed to run nu. Unless you are working in an environment where only the nu image will be deployed and you have space constraints, it's highly recommended to use the alpine image if you aim for small image size. Only use this image if you really need both glibc and small image size.

nu:<version>-alpine

This image is based on the popular Alpine Linux project, available in the alpine official image. Alpine Linux is much smaller than most distribution base images (~5MB), and thus leads to much slimmer images in general.

This variant is highly recommended when final image size being as small as possible is desired. The main caveat to note is that it does use musl libc instead of glibc and friends, so certain software might run into issues depending on the depth of their libc requirements. However, most software doesn't have an issue with this, so this variant is usually a very safe choice. See this Hacker News comment thread for more discussion of the issues that might arise and some pro/con comparisons of using Alpine-based images.

To minimize image size, it's uncommon for additional related tools (such as git or bash) to be included in Alpine-based images. Using this image as a base, add the things you need in your own Dockerfile (see the alpine image description for examples of how to install packages if you are unfamiliar).

nu:<version>-<libc-variant>

This image is based on scratch which doesn't create an extra layer. This variants can be handy in a project that uses multiple programming language as you need a lot of tools. By using this in multi-stage build, you can slim down the docker image that need to be pulled.

example

• using glibc variant

FROM nu:0.2-glibc as shell
FROM node:slim

# Build your plugins

COPY --from=shell /bin/nu /bin/
# Something else
ENTRYPOINT ["nu"]

• using musl variant

FROM nu:musl as shell
FROM go:alpine

# Build your plugins

COPY --from=shell /bin/nu /bin/
# Something else
ENTRYPOINT ["nu"]

nu:<version>-<libc-variant>-distroless

This image is base on Distroless which usually to contain only your application and its runtime dependencies. This image do not contain package managers, shells or any other programs you would expect to find in a standard Linux distribution except for nushell itself. All distroless variant always contains:

• ca-certificates
• A /etc/passwd entry for a root user
• A /tmp directory
• tzdata

As for glibc-distroless variant, it adds:

• glibc
• libssl
• openssl

Most likely you want to use this in CI/CD environment for plugins that can be statically compiled.

example

FROM nu:musl-distroless

COPY target/x86_64-unknown-linux-musl/release/nu_plugin_* /bin/
ENTRYPOINT ["nu"]

nu:<version>-<libc-variant>-busybox

This image is based on Busybox which is a very good ingredient to craft space-efficient distributions. It combines tiny versions of many common UNIX utilities into a single small executable. It also provides replacements for most of the utilities you usually find in GNU fileutils, shellutils, etc. The utilities in BusyBox generally have fewer options than their full-featured GNU cousins; however, the options that are included provide the expected functionality and behave very much like their GNU counterparts. Basically, this image provides a fairly complete environment for any small or embedded system.

Use this only if you need common utilities like tar, awk, and many more but don't want extra blob like nushell plugins and others.

example

FROM nu:0.2-glibc-busybox

ADD https://github.com/user/repo/releases/download/latest/nu_plugin_cowsay.tar.gz /tmp/
RUN tar xzfv nu_plugin_cowsay.tar.gz -C /bin --strip=1 nu_plugin_cowsay

ENTRYPOINT ["nu"]