Jib – Containerize Your Java Application

Building containerized applications require a lot of configurations. If you are building a Java application and planning to use Docker, you might need to consider Jib. Jib is an opensource plugin for Maven and Gradle. It uses the build information to build a Docker image without requiring a Dockerfile and Docker daemon. In this article, we will build a simple Spring Boot application with Jib Maven configuration to see Jib in action. The pom.xml configuration with Jib is given below.

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>
   <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>2.2.5.RELEASE</version>
      <relativePath />
      <!-- lookup parent from repository -->
   </parent>
   <groupId>org.smarttechie</groupId>
   <artifactId>jib-demo</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <name>jib-demo</name>
   <description>Demo project for Spring Boot</description>
   <properties>
      <java.version>1.8</java.version>
   </properties>
   <dependencies>
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter</artifactId>
      </dependency>
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-web</artifactId>
      </dependency>
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-test</artifactId>
         <scope>test</scope>
         <exclusions>
            <exclusion>
               <groupId>org.junit.vintage</groupId>
               <artifactId>junit-vintage-engine</artifactId>
            </exclusion>
         </exclusions>
      </dependency>
   </dependencies>
   <!-- The below configuration is for Jib -->
   <build>
      <plugins>
         <plugin>
            <groupId>com.google.cloud.tools</groupId>
            <artifactId>jib-maven-plugin</artifactId>
            <version>2.1.0</version>
            <configuration>
               <to>
		        <!-- I configured Docker Image to be pushed to DockerHub -->
                  <image>2013techsmarts/jib-demo</image>
               </to>
               <auth>
		        <!-- Used simple Auth mechanism to authorize DockerHub Push -->
                  <username>xxxxxxxxx</username>
                  <password>xxxxxxxxx</password>
               </auth>
            </configuration>
         </plugin>
      </plugins>
   </build>
</project>

After the above change, use the below Maven command to build the image and push that image to DockerHub. If you face any authentication issues with DockerHub, refer https://github.com/GoogleContainerTools/jib/tree/master/jib-maven-plugin#authentication-methods

mvn compile jib:build

Now, pull the image which we created with the above command to run it.

docker image pull 2013techsmarts/jib-demo
docker run -p 8080:8080 2013techsmarts/jib-demo

That’s it. No more additional skill is required to create a Docker Image.