This repository pulls a Unison program from Unison Share, compiles it, and builds a Docker image that runs the compiled program. You should be able to fork it, change a few configuration settings, and containerize your own Unison program.

make build

This will print some Docker logs to the terminal and build some images. The main image that we care about will be named unison-application and will be now have a latest tag and a tag based on the release version of the Unison project that we are building.

docker run -p 8081:8081 unison-application

The default program is a web server that you should now be able to send requests to:

❯ curl -i localhost:8081/hello
HTTP/1.1 200 OK
Content-Length: 11

Hello World

If you containerize another Unison program, then you may be able to run docker run unison-application without exposing port 8081.

To containerize another Unison program, you need to change a few configuration settings at the top of the Makefile:

• SHARE_USER (default: unison)
  • The handle of the Unison Share user who has published the code
• SHARE_PROJECT (default: http)
  • The name of the Unison Share project within the scope of the Unison Share user
• PROJECT_RELEASE (default: 3.0.2)
  • The release version of the Unison Share project.
• MAIN_FUNCTION (default: example.main)
  • The name of the main function to run within the application. This will generally have the type '{Exception, IO} ().

Now you should be able to build and run your own Unison program!

If you would prefer your container to have a name other than unison-application, you can find/replace all occurrences of unison-application in Makefile and docker/Dockerfile.

The code/configuration to build the Docker container is a bit more complex than one might expect. There are a few reasons for this complexity:

The most efficient way to run a Unison program is to first compile it and then to run the compiled binary. This adds a couple of steps to the build.

The methods used to achieve compiling produce some temporary files that we don't care about for the final image that runs the Unison program. This repository uses Docker multi-stage builds to keep the extra files out of the final image, at the cost of a bit of extra noise in the Dockerfile.