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Docker Scala Application Example

Docker allows us to execute Scala application. Here, we are creating a Scala file and executing that using the docker. This example includes the following steps.

1. Create a directory to organize application files.
$ mkdir scala-docker-app



2. Change working directory
$ cd scala-docker-app



3. Create a Dockerfile

// Dockerfile

FROM williamyeh/java7 MAINTAINER William Yeh <william.pjyeh@gmail.com> ENV SCALA_VERSION 2.10.4 ENV SCALA_TARBALL http://www.scala-lang.org/files/archive/scala-$SCALA_VERSION.deb RUN echo “==> Install curl helper tool…”&& apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y –force-yes curl && echo “===> install from Typesafe repo (contains old versions but they have all dependencies we need later on)”&& curl -sSL http://apt.typesafe.com/repo-deb-build-0002.deb -o repo-deb.deb && dpkg -i repo-deb.deb && apt-get update && echo “===> install Scala”&& DEBIAN_FRONTEND=noninteractive apt-get install -y –force-yes libjansi-java && curl -sSL $SCALA_TARBALL -o scala.deb && dpkg -i scala.deb && echo “===> clean up…”&& rm -f *.deb && apt-get remove -y –auto-remove curl && apt-get clean && rm -rf /var/lib/apt/lists/* COPY . /root WORKDIR /root Run scalac index.scala
4. Create a Scala file

// index.scala

object MainObject{ def main(args:Array[String]){ println(“Hello by Scala”); } }
5. Create a Docker Image

Now, we are creating a Docker image of this Scala application. The following command is used to create Docker image.

$ docker build -t scala-app .



6. Run Scala Docker image
$ docker run scala-app

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