title: What exactly does "-Djava.security.egd=file:/dev/./urandom" do when containerizing a Spring Boot application
body: <pre><code>FROM openjdk:8-jdk-alpine
  VOLUME /tmp
  ARG JAR_FILE
  COPY ${JAR_FILE} app.jar
  ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"]
  </code></pre>
  
  <p>The above <code>Dockerfile</code> sample is from the official <a href="https://spring.io/guides/gs/spring-boot-docker/" rel="noreferrer">Spring Boot guide</a> for docker. I would like to know what the security property is used for since I don't usually set that up when running the app on my local development environment but it seems to come up on various containerization guides. Cheers!</p>