Docker Scala应用程序示例

Docker允许我们执行Scala应用程序。 在这里，我们将演示如何创建一个Scala文件，并使用docker进行执行，此示例包括以下步骤。

1. 创建一个目录用来组织应用程序文件。

$ mkdir - /home/zyiz/docker/scala-docker-app

1. 更改进入工作目录

$ cd /home/zyiz/docker/scala-docker-app

1. 创建一个名称为 Dockerfile 的 Dockerfile 文件

FROM williamyeh/java7  
MAINTAINER Hema (zyiz.net@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 . /home/zyiz/src
WORKDIR /home/zyiz/src
CMD ["scala", "/home/zyiz/src/index.scala"]

1. 创建Scala文件: /home/zyiz/docker/scala-docker-app/index.scala

object MainObject{  
    def main(args:Array[String]){  
        println("Hello by Scala");  
    }  
}

现在，创建这个Scala应用程序的Docker映像。 以下命令用于创建Docker映像。

zyiz@ubuntu:~/docker/scala-docker-app$ sudo docker build -t scala-app .

执行上面代码，输出结果如下 -

zyiz@ubuntu:~/docker/scala-docker-app$ sudo docker build -t scala-app .
Sending build context to Docker daemon  3.584kB
.......
Removing intermediate container a551438ab33a
......
 ---> Running in bc8b748316cc
 ---> 1d786cf20101
Removing intermediate container bc8b748316cc
Successfully built 1d786cf20101
Successfully tagged scala-app:latest
zyiz@ubuntu:~/docker/scala-docker-app$

1. 运行Scala Docker映像

zyiz@ubuntu:~/docker/scala-docker-app$ sudo docker run scala-app

执行上面代码，得到以下结果 -

zyiz@ubuntu:~/docker/scala-docker-app$ sudo docker run scala-app
Hello by Scala
zyiz@ubuntu:~/docker/scala-docker-app$ sudo docker run scala-app