clojure-demos/resources/public/documents/containers.org

Containerizing your application

This is a multistage Dockerfile it has a build and run stage to help reduce the final image size.

This example is built for use with polylith it allows you to build multiple containers from a single docker file.

# Beware the alpine images, seems the googleads library does not like the alphine glib alternative ie muscl
FROM clojure:temurin-17-tools-deps AS builder
ENV CLOJURE_VERSION=1.11.1.1182
ARG PROJECT

RUN mkdir -p /build
WORKDIR /build

# Fetch the deps first, by copying just the deps we can cache the download
# except when the deps file has changed.
COPY ./deps.edn /build
RUN clojure -P -X:dev

COPY ./ /build
RUN clojure -T:build uberjar :project $PROJECT

FROM eclipse-temurin:17
ARG PROJECT
COPY --from=builder /build/target/ /app

WORKDIR /app

ADD ./projects/car-cli/resources/google/ /app/
ADD ./projects/car-cli/resources/google/ /root/
RUN mkdir -p /app/environment/

# Build ARG are not available at runtime but we can insert them into env as part of the build
ENV PROJECT_RUN=/app/${PROJECT}.jar

ENTRYPOINT ["java", "-jar"]

# this is expanded by a shell so can't use in a params list, can't find another way
CMD java -jar ${PROJECT_RUN}.jar

docker build -f Dockerfile-Multistage . --build-arg PROJECT=example-api