Node.js
The official Node.js docker image, made with love by the node community.
Table of Contents
- What is Node.js?
- Usage
- How to use this image
- Image Variants
- License
- Supported Docker versions
- Governance and Current Members
What is Node.js?
Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.
See: http://nodejs.org
Usage
How to use this image
Dockerfile
in your Node.js app project
Create a FROM node:4-onbuild
# replace this with your application's default port
EXPOSE 8888
You can then build and run the Docker image:
$ docker build -t my-nodejs-app .
$ docker run -it --rm --name my-running-app my-nodejs-app
Notes
The image assumes that your application has a file named
package.json
listing its
dependencies and defining its start
script.
It also assumes that you have a file named .dockerignore
otherwise it will copy your local npm modules:
node_modules
We have assembled a Best Practices Guide for those using these images on a daily basis.
Run a single Node.js script
For many simple, single file projects, you may find it inconvenient to write a
complete Dockerfile
. In such cases, you can run a Node.js script by using the
Node.js Docker image directly:
$ docker run -it --rm --name my-running-script -v "$PWD":/usr/src/app -w
/usr/src/app node:4 node your-daemon-or-script.js
Verbosity
By default the Node.js Docker Image has npm log verbosity set to info
instead
of the default warn
. This is because of the way Docker is isolated from the
host operating system and you are not guaranteed to be able to retrieve the
npm-debug.log
file when npm fails.
When npm fails, it writes it's verbose log to a log file inside the container.
If npm fails during an install when building a Docker Image with the docker build
command, this log file will become inaccessible when Docker exits.
The Docker Working Group have chosen to be overly verbose during a build to provide an easy audit trail when install fails. If you prefer npm to be less verbose you can easily reset the verbosity of npm using the following techniques:
Dockerfile
If you create your own Dockerfile
which inherits from the node
image you can
simply use ENV
to override NPM_CONFIG_LOGLEVEL
.
FROM node
ENV NPM_CONFIG_LOGLEVEL warn
...
Docker Run
If you run the node image using docker run
you can use the -e
flag to
override NPM_CONFIG_LOGLEVEL
.
$ docker run -e NPM_CONFIG_LOGLEVEL=warn node ...
NPM run
If you are running npm commands you can use --loglevel
to control the
verbosity of the output.
$ docker run node npm --loglevel=warn ...
Image Variants
The node
images come in many flavors, each designed for a specific use case.
All of the images contain pre-installed versions of node
,
npm
, and yarn
.
node:<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. This tag is based off of
buildpack-deps
.
buildpack-deps
is designed for the average user of docker who has many images
on their system. It, by design, has a large number of extremely common Debian
packages. This reduces the number of packages that images that derive from it
need to install, thus reducing the overall size of all images on your system.
node: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).
node:onbuild
This image makes building derivative images easier. For most use cases, creating
a Dockerfile
in the base of your project directory with the line FROM node:onbuild
will be enough to create a stand-alone image for your project.
While the onbuild
variant is really useful for "getting off the ground
running" (zero to Dockerized in a short period of time), it's not recommended
for long-term usage within a project due to the lack of control over when the
ONBUILD
triggers fire (see also
docker/docker#5714
,
docker/docker#8240
,
docker/docker#11917
).
Once you've got a handle on how your project functions within Docker, you'll
probably want to adjust your Dockerfile
to inherit from a non-onbuild
variant and copy the commands from the onbuild
variant Dockerfile
(moving
the ONBUILD
lines to the end and removing the ONBUILD
keywords) into your
own file so that you have tighter control over them and more transparency for
yourself and others looking at your Dockerfile
as to what it does. This also
makes it easier to add additional requirements as time goes on (such as
installing more packages before performing the previously-ONBUILD
steps).
This onbuild
variant will only install npm packages according to the
package.json
and does not adhere to the npm-shrinkwrap.json
(see full
discussion in
nodejs/docker-node#65
.
Note that npm installs devDependencies by default, which is undesirable if
you're building a production image. To avoid this pass NODE_ENV as a build
argument i.e. docker build --build-arg NODE_ENV=production …
.
node:slim
This image does not contain the common packages contained in the default tag and
only contains the minimal packages needed to run node
. Unless you are working
in an environment where only the Node.js image will be deployed and you have
space constraints, we highly recommend using the default image of this
repository.
License
License information for the software contained in this image. License information for the Node.js Docker project.
Supported Docker versions
This image is officially supported on Docker version 1.9.1.
Support for older versions (down to 1.6) is provided on a best-effort basis.
Please see the Docker installation documentation for details on how to upgrade your Docker daemon.
Governance and Current Members
The Node.js Docker Image is governed by the Docker Working Group. See GOVERNANCE.md to learn more about the group's structure and CONTRIBUTING.md for guidance about the expectations for all contributors to this project.
Docker Working Group Members
- Christopher Horrell (chorrell)
- Hans Kristian Flaatten (starefossen)
- Hugues Malphettes (hmalphettes)
- John Mitchell (jlmitch5)
- Peter Petrov (pesho)
- William Blankenship (retrohacker)
Docker Working Group Collaborators
- Mikeal Rogers (mikeal)
- Laurent Goderre (LaurentGoderre)