• latest, lein-2.5.3 (Dockerfile)
• onbuild, lein-2.5.3-onbuild (onbuild/Dockerfile)

For more information about this image and its history, please see the relevant manifest file (library/clojure). This image is updated via pull requests to the docker-library/official-images GitHub repo.

For detailed information about the virtual/transfer sizes and individual layers of each of the above supported tags, please see the clojure/tag-details.md file in the docker-library/docs GitHub repo.

Clojure is a dialect of the Lisp programming language. It is a general-purpose programming language with an emphasis on functional programming. It runs on the Java Virtual Machine, Common Language Runtime, and JavaScript engines. Like other Lisps, Clojure treats code as data and has a macro system.

wikipedia.org/wiki/Clojure

Since the most common way to use Clojure is in conjunction with Leiningen (lein), this image assumes that's how you'll be working. The most straightforward way to use this image is to add a Dockerfile to an existing Leiningen/Clojure project:

FROM clojure
COPY . /usr/src/app
WORKDIR /usr/src/app
CMD ["lein", "run"]

Then, run these commands to build and run the image:

$ docker build -t my-clojure-app .
$ docker run -it --rm --name my-running-app my-clojure-app

While the above is the most straightforward example of a Dockerfile, it does have some drawbacks. The lein run command will download your dependencies, compile the project, and then run it. That's a lot of work, all of which you may not want done every time you run the image. To get around this, you can download the dependencies and compile the project ahead of time. This will significantly reduce startup time when you run your image.

FROM clojure
RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app
COPY project.clj /usr/src/app/
RUN lein deps
COPY . /usr/src/app
RUN mv "$(lein uberjar | sed -n 's/^Created \(.*standalone\.jar\)/\1/p')" app-standalone.jar
CMD ["java", "-jar", "app-standalone.jar"]

Writing the Dockerfile this way will download the dependencies (and cache them, so they are only re-downloaded when the dependencies change) and then compile them into a standalone jar ahead of time rather than each time the image is run.

You can then build and run the image as above.

If you have an existing Lein/Clojure project, it's fairly straightforward to compile your project into a jar from a container:

$ docker run -it --rm -v "$PWD":/usr/src/app -w /usr/src/app clojure lein uberjar

This will build your project into a jar file located in your project's target/uberjar directory.

The clojure 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 image makes building derivative images easier. For most use cases, creating a Dockerfile in the base of your project directory with the line FROM clojure: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).

View license information for the software contained in this image.

This image is officially supported on Docker version 1.10.3.

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.

Documentation for this image is stored in the clojure/ directory of the docker-library/docs GitHub repo. Be sure to familiarize yourself with the repository's README.md file before attempting a pull request.

If you have any problems with or questions about this image, please contact us through a GitHub issue. If the issue is related to a CVE, please check for a cve-tracker issue on the official-images repository first.

You can also reach many of the official image maintainers via the #docker-library IRC channel on Freenode.

You are invited to contribute new features, fixes, or updates, large or small; we are always thrilled to receive pull requests, and do our best to process them as fast as we can.

Before you start to code, we recommend discussing your plans through a GitHub issue, especially for more ambitious contributions. This gives other contributors a chance to point you in the right direction, give you feedback on your design, and help you find out if someone else is working on the same thing.