Running the server locally
julia ./api/mux_server.jl 7777
where 7777 is the port you want it to host on. You can then access it at http://localhost:7777.
Building the Docker image
docker build -t diffeqonline-server .
You can run the image with
docker run -i -t --rm -p 7777:7777 -e PORT=7777 diffeqonline-server
which will host it at http://192.168.99.100:7777 rather than at localhost. The IP might vary.
You can run a interactive version of the container and not start the server with
docker run -dit -p 7777:7777 --entrypoint=/bin/bash diffeqonline-server
This does still open up the port in case you want to run some testing.
Deploying to Heroku
General instructions can be found here, but it's pretty much just
heroku container:push web --app AppName
You need to make sure you are properly authenticated with the Heroku CLI for this to work.