Supported tags and respective
Where to file issues:
the Docker Community
Supported Docker versions:
the latest release (down to 1.6 on a best-effort basis)
What is Ruby?
Ruby is a dynamic, reflective, object-oriented, general-purpose, open-source programming language. According to its authors, Ruby was influenced by Perl, Smalltalk, Eiffel, Ada, and Lisp. It supports multiple programming paradigms, including functional, object-oriented, and imperative. It also has a dynamic type system and automatic memory management.
How to use this image
Dockerfile in your Ruby app project
FROM arm32v7/ruby:2.5 # throw errors if Gemfile has been modified since Gemfile.lock RUN bundle config --global frozen 1 WORKDIR /usr/src/app COPY Gemfile Gemfile.lock ./ RUN bundle install COPY . . CMD ["./your-daemon-or-script.rb"]
Put this file in the root of your app, next to the
You can then build and run the Ruby image:
$ docker build -t my-ruby-app . $ docker run -it --name my-running-script my-ruby-app
The above example
Dockerfile expects a
Gemfile.lock in your app directory. This
docker run will help you generate one. Run it in the root of your app, next to the
$ docker run --rm -v "$PWD":/usr/src/app -w /usr/src/app arm32v7/ruby:2.5 bundle install
Run a single Ruby script
For many simple, single file projects, you may find it inconvenient to write a complete
Dockerfile. In such cases, you can run a Ruby script by using the Ruby Docker image directly:
$ docker run -it --rm --name my-running-script -v "$PWD":/usr/src/myapp -w /usr/src/myapp arm32v7/ruby:2.5 ruby your-daemon-or-script.rb
By default, Ruby inherits the locale of the environment in which it is run. For most users running Ruby on their desktop systems, that means it's likely using some variation of
en_US.UTF-8, etc). In Docker however, the default locale is
C, which can have unexpected results. If your application needs to interact with UTF-8, it is recommended that you explicitly adjust the locale of your image/container via
-e LANG=C.UTF-8 or
ENV LANG C.UTF-8.
This image sets several environment variables which change the behavior of Bundler and Gem for running a single application within a container (especially in such a way that the development sources of the application can be bind-mounted inside a container and not have
.bundle from the host interfere with the proper functionality of the container).
The environment variables we set are canonically listed in the above-linked
Dockerfiles, but some of them include
If these cause issues for your use case (running multiple Ruby applications in a single container, for example), setting them to the empty string should be sufficient for undoing their behavior.
arm32v7/ruby images come in many flavors, each designed for a specific use case.
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 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.
This image does not contain the common packages contained in the default tag and only contains the minimal packages needed to run
arm32v7/ruby. Unless you are working in an environment where only the
arm32v7/ruby image will be deployed and you have space constraints, we highly recommend using the default image of this repository.
View license information for the software contained in this image.
As with all Docker images, these likely also contain other software which may be under other licenses (such as Bash, etc from the base distribution, along with any direct or indirect dependencies of the primary software being contained).
Some additional license information which was able to be auto-detected might be found in the
As for any pre-built image usage, it is the image user's responsibility to ensure that any use of this image complies with any relevant licenses for all software contained within.