Crystal Docker for development

dev.dockerfile

FROM crystallang/crystal:0.22.0
MAINTAINER sam@eaton.party
WORKDIR /app

# copy all your app files/directories to image 
COPY static ./static
COPY dev ./dev
COPY spec ./spec
COPY src ./src
COPY shard.yml ./shard.yml

# install crystal deps
RUN shards install
RUN crystal build --release dev/sentry_cli.cr -o ./sentry

# run sentry, which starts app and watches files
CMD ./sentry

run.sh

# build image
docker build -f dev.dockerfile -t my_app .

# run image
# port 7777 on local machine is mapped to port 80 in container
docker run --name my_app -p 7777:80 my_app