Simplify installs; Adjust docs

Author: JannikArndt

Dockerfile

@@ -3,31 +3,33 @@
 # - AWS CLI
 # - kubectl
 # - sonar-scanner
-# - Java 8 JDK (from base image)
-# - SBT (from base image)
+# - SBT (overwrites base image with newer version)
+# - Java 11.0.X JDK (from base image)
 # - Docker (from base image)
 
 # Pull base image (https://circleci.com/docs/2.0/circleci-images/#openjdk)
 # https://github.com/CircleCI-Public/circleci-dockerfiles/blob/master/openjdk/images/8u232-jdk/Dockerfile
-FROM circleci/openjdk:11.0.5-jdk-stretch
+FROM circleci/openjdk:11-jdk-stretch
 
 # Environment variables
 ENV SCALA_VERSION=2.13.1
-ENV KUBECTL_VERSION=v1.16.1
+ENV SBT_VERSION=1.3.3
 ENV SONAR_SCANNER_VERSION=3.3.0.1492
 ENV SONAR_SCANNER_PACKAGE=sonar-scanner-cli-${SONAR_SCANNER_VERSION}.zip
 
 USER root
 
 SHELL ["/bin/bash", "-eo", "pipefail", "-x", "-c"]
 
+# Fix apt-get
+RUN apt-get update && apt-get install -y apt-transport-https
+
 # Install current SBT
-RUN apt-get update && apt-get install apt-transport-https
 RUN echo "deb https://dl.bintray.com/sbt/debian /" | tee -a /etc/apt/sources.list.d/sbt.list
 RUN curl -sL "https://keyserver.ubuntu.com/pks/lookup?op=get&search=0x2EE0EA64E40A89B84B2DF73499E82A75642AC823" | apt-key add
 RUN apt-get update && apt-get install sbt
-RUN mkdir project && echo "sbt.version=1.3.3" > project/build.properties && echo "scalaVersion := \"2.13.1\"" > build.sbt
-RUN sbt sbtVersion
+RUN echo "scalaVersion := \"$SCALA_VERSION\"" > build.sbt
+RUN sbt sbtVersion scalaVersion -Dsbt.version=$SBT_VERSION
 
 # Install the AWS CLI
 RUN curl -sSL https://s3.amazonaws.com/aws-cli/awscli-bundle.zip -o awscli-bundle.zip && \
@@ -38,10 +40,10 @@ RUN curl -sSL https://s3.amazonaws.com/aws-cli/awscli-bundle.zip -o awscli-bundl
   /usr/local/bin/aws --version
 
 # Install kubectl
-RUN curl -LO https://storage.googleapis.com/kubernetes-release/release/${KUBECTL_VERSION}/bin/linux/amd64/kubectl && \
-  mv kubectl /usr/local/bin/kubectl && \
-  chmod +x /usr/local/bin/kubectl && \
-  kubectl version --client
+RUN curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
+RUN echo "deb https://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee -a /etc/apt/sources.list.d/kubernetes.list
+RUN apt-get update && apt-get install -y kubectl
+RUN kubectl version --client
 
 # Install Sonar-Scanner
 RUN curl -LO https://binaries.sonarsource.com/Distribution/sonar-scanner-cli/$SONAR_SCANNER_PACKAGE && \
@@ -56,4 +58,4 @@ USER circleci
 # Define working directory
 WORKDIR /home/circleci
 
-RUN echo -e "Tag for this image:\n11.0.5-${SCALA_VERSION}-${KUBECTL_VERSION}"
+RUN echo -e "Tag for this image:\njava11-${SCALA_VERSION}-${SBT_VERSION}"

README.md

@@ -1,27 +1,43 @@
-# Dockerfile with Scala, SBT, Kubernetes, AWS CLI and Docker
+# Builder image for Scala 2.13.x on JVM11
 
-This repository contains **Dockerfile** of:
-* [Scala](http://www.scala-lang.org)
-* [sbt](http://www.scala-sbt.org)
-* [kubectl](https://kubernetes.io/docs/reference/kubectl/overview/)
-* [AWS CLI](https://aws.amazon.com/cli/)
+Includes
+* [Scala 2.13.x](http://www.scala-lang.org)
+* [sbt 1.3.x](http://www.scala-sbt.org)
+* [kubectl (latest)](https://kubernetes.io/docs/reference/kubectl/overview/)
+* [AWS CLI (latest)](https://aws.amazon.com/cli/)
 * [Docker](https://www.docker.com/)
-* [Sonar-Scanner](https://docs.sonarqube.org/latest/)
+* [Sonar-Scanner (3.3.x)](https://docs.sonarqube.org/latest/)
 
 ## Base Docker Image ##
 
-* `circleci/openjdk:8u222-jdk-stretch` provides the JDK, SBT and Docker.
-  * [Dockerfile](https://github.com/CircleCI-Public/circleci-dockerfiles/blob/master/openjdk/images/8u222-jdk-stretch/Dockerfile)
+* `circleci/openjdk:11-jdk-stretch` provides the JDK and Docker.
+  * [Dockerfile](https://github.com/CircleCI-Public/circleci-dockerfiles/blob/master/openjdk/images/11.0.5-jdk-stretch/Dockerfile)
   * [background](https://circleci.com/docs/2.0/circleci-images/#openjdk)
-  * [Tag on Dockerhub](https://hub.docker.com/r/circleci/openjdk/tags?page=1&name=8u222-jdk-stretch)
+  * [Tag on Dockerhub](https://hub.docker.com/r/circleci/openjdk/tags?page=1&name=11-jdk-stretch)
 
 ## Additions ##
 
-We add Scala (version in tag), AWS CLI (latest), Kubectl (version in tag) and Sonar-Scanner (version `3.3`).
+We install and initialize `sbt` (latest 1.3.X) and `scala` (latest 2.13.X), the AWS CLI (latest), Kubectl (latest) and Sonar-Scanner (version `3.3`).
+
+## Usage ##
+
+If you use CircleCi, you can reference this image in your `.circleci/config.yml`:
+
+```yaml
+jobs:
+  build:
+    docker:
+      - image: moia/scala-on-circleci:java11
+    steps:
+      - checkout
+      - run: sbt compile
+```
+
+In your `build.sbt`, set `scalaVersion := "2.13.1"` and `scalacOptions := Seq("-target:11")`.
 
 ## Dockerhub ##
 
-This image is automatically released to Dockerhub for every tag: https://hub.docker.com/r/moia/scala-on-circleci
+This image is automatically released to Dockerhub for every tag: https://hub.docker.com/r/moia/scala-on-circleci/tags?page=1&name=java11
 
 ## License ##