Generic dockerfile for statically compiled Crystal applications

gistfile1.txt

# See https://wjwh.eu/posts/2019-07-21-static-crystal-images.html for the reasoning behind each line 
# Build stage 
FROM durosoft/crystal-alpine:0.28.0 as build

COPY shard.yml shard.yml
RUN shards install --production

COPY . ./
RUN crystal build src/my_app.cr --release --static

# Release stage
FROM alpine:3.10
COPY --from=0 my_app my_app
EXPOSE 3000 # Or whichever other port you want exposed, if any