A multi-stage Docker Crystal build using Alpine.

The final Docker image size is 15.4MB.

Build

docker build -t app.cr -f Dockerfile .

Build w/ --release

docker build -t app.cr --build-arg CRYSTAL_BUILD_ARGS=--release -f Dockerfile .

Run

docker stop app.cr || true && docker rm app.cr || true && \
docker run -p3000:3000 --name app.cr app.cr:latest

Build w/ --release & Run

docker stop app.cr || true && docker rm app.cr || true && \
docker run -p3000:3000 --name app.cr app.cr:latest