Use multistage Docker build

.circleci/config.yml

+---
+
+version: 2
+jobs:
+  build:
+    working_directory: ~/src
+    docker:
+      - image: hbpmip/docker-compose-for-ci:17.06-0
+    environment:
+       - CIRCLECI: true
+    steps:
+      - setup_remote_docker:
+          version: 17.06.0-ce
+      - checkout
+      - run:
+          name: "Install requirements"
+          command: |
+            docker --version
+            pre-commit install
+      - run:
+          name: "Validate code quality"
+          command: |
+            pre-commit run --all-files
+      - run:
+          name: "Build project"
+          command: |
+            PATH=$PATH:/$HOME/.captain/bin/ ./build.sh
+      - run:
+          name: "Test project"
+          command: |
+            PATH=$PATH:/$HOME/.captain/bin/ ./test.sh
+
+    notify:
+      webhooks:
+      - url: 'https://webhook.atomist.com/atomist/circle'

Dockerfile

+# Build stage for Java classes
+FROM hbpmip/java-base-build:3.5.0-jdk-8-6 as java-build-env
+
+COPY pom.xml /project/
+COPY src/ /project/src/
+
+# Repeating the file copy works better. I dunno why.
+RUN cp /usr/share/maven/ref/settings-docker.xml /root/.m2/settings.xml \
+    && mvn clean package
+
 FROM openjdk:8u131-jre-alpine
 MAINTAINER Mirco Nasuti <mirco.nasuti@chuv.ch>
 
@@ -13,10 +23,10 @@ RUN apk add --no-cache --update ca-certificates wget \
     && tar -C /usr/local/bin -xzvf /tmp/dockerize.tar.gz \
     && rm -rf /var/cache/apk/* /tmp/*
 
-COPY docker/runner/config/application.tmpl /config/application.tmpl
-COPY docker/runner/README.md docker/runner/run.sh /
+COPY docker/config/application.tmpl /config/application.tmpl
+COPY docker/README.md docker/run.sh /
 
-COPY target/portal-backend.jar backend.jar
+COPY --from=java-build-env /project/target/portal-backend.jar /usr/share/jars/
 
 EXPOSE 8080
 

Dockerfile.builder

-# Pull base image
-FROM maven:3.5.0-jdk-8-alpine
-
-MAINTAINER mirco.nasuti@chuv.ch
-
-# Create a user with id 1000, with some luck it should match your user on the host machine.
-RUN adduser --quiet --uid 1000 build
-USER build
-
-COPY ./docker/builder/build-in-docker.sh /
-
-# Volume
-VOLUME /build
-# Define working directory
-WORKDIR /build
-
-ENTRYPOINT ["/build-in-docker.sh"]

captain.yml

-# Builder image
-# Creates a portable environemnt to build this project.
-# Do not push this image to Docker hub.
-builder:
-  build: Dockerfile.builder
-  image: portal-backend-builder
-  pre:
-    - echo "Building portal backend builder image"
-  post:
-    - echo "Finished building portal backend builder image"
-    - echo "Building project..."
-    - docker run --rm -v $WORKSPACE:/build/ -v $HOME/.m2:/home/build/.m2/ portal-backend-builder:latest
-    - echo "Finished building project"
-
-portal-backend:
+target_image:
   build: Dockerfile
   image: hbpmip/portal-backend
   pre:

circle.yml

-machine:
-  services:
-    - docker
-dependencies:
-  cache_directories:
-    - "~/.m2"
-  override:
-    - docker info
-    - docker build -f Dockerfile.builder -t portal-backend-builder .
-    - docker run --rm -v $HOME/portal-backend:/build/ -v $HOME/.m2:/home/build/.m2/ portal-backend-builder:latest
-    - docker build -t hbpmip/portal-backend .
-test:
-  pre:
-    - ./tests/pre-test-run.sh
-  override:
-    - ./tests/test-run.sh
-# deployment:
-#   hub:
-#     branch: master
-#     commands:
-#       - docker login -u $DOCKER_HUB_USER -p $DOCKER_HUB_PASS -e $DOCKER_HUB_EMAIL
-#       - docker push --branch-tags=false --commit-tags=true
-#       - mvn sonar:sonar -Dsonar.login=$SONAR_KEY  # Need SonarQube back on a public URL
-notify:
-  webhooks:
-  - url: 'https://webhook.atomist.com/atomist/circle'

docker/builder/build-in-docker.sh

-#!/usr/bin/env bash
-
-echo ">>> Building inside Docker"
-
-echo "Removing old target folder..."
-rm -rf target/
-
-echo "Packaging..."
-mvn package
-
-echo ">>> Backend build is complete"

docker/runner/run.sh → docker/run.sh

@@ -10,4 +10,4 @@ fi
 if [ ! -z "$FEATURES_DB_SERVER" ]; then
   OPTS="$OPTS -wait tcp://$FEATURES_DB_SERVER -timeout 60s"
 fi
-dockerize $OPTS java -jar backend.jar
+dockerize $OPTS java -jar /usr/share/jars/portal-backend.jar