Build a Docker Image and Run a Docker Container with docker maven plugin fabric8.io

 

Introduction

 The maven plugin for docker fabric8io/docker-maven-plugin helps us in building docker images and running containers. In case you are thinking about the difference between an image and container then please note that a running image is called container.

1. For below steps, I have used Spring Boot Rest service project which is connected to MongoDB. See below link for reference.

   Read Here: How to Connect to Spring Boot Rest Service Image to MongoDB

2. Using io.fabric8 plugin, under the plugin section add the io.fabric8 plugin
   
   <plugin> <groupId>io.fabric8</groupId> <artifactId>docker-maven-plugin</artifactId> <version>0.20.0</version>....

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   <plugin> <groupId>io.fabric8</groupId> <artifactId>docker-maven-plugin</artifactId> <version>0.20.0</version>....

3. We need to first build the image from Dockerfile, this plugin supports all the command which are in Dockerfile but I think making docker image from Docker file is much easier and simpler. So I telling the maven plugin in below step to look for Dockerfile in root( project base directory)
   
   <name>springboot-mongo-dockerimage:${project.version}</name> <alias>springboot-mongo-dockerimage</alias> <build> <dockerFileDir>${project.basedir}</dockerFileDir> </build>

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   <name>springboot-mongo-dockerimage:${project.version}</name>     <alias>springboot-mongo-dockerimage</alias> <build>     <dockerFileDir>${project.basedir}</dockerFileDir> </build>

4. Next step is to specify what docker container needs to do when it runs.
   1. Since we want to make sure that mongo DB container should be running before this image starts running. We add a tag called <dependsOn>.
   2. If the MongoDB is started we would like to link this container to Mongo so both can talk to each other, we specify that by adding a tag called <link>
      
      <dependsOn> <container>mongo</container> </dependsOn> <links> <link>mongo</link> </links>

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      <dependsOn> <container>mongo</container> </dependsOn> <links> <link>mongo</link> </links>

   3. Next, we will specify on which port we would like to run this container and which port it should map to localhost machine
      
      <ports> <port>9876:8080</port> </ports>

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      <ports> <port>9876:8080</port> </ports>

   4. We enable all the logging using <log> tag, so we could see any errors or debug if some problem arises.
5. Next, we will add execution phases, we will cover these steps
   1. Remove an existing image, if it exists
   2. Build the Image
   3. Deploy the image
      
      <executions> <execution> <id>start</id> <phase>pre-integration-test</phase> <goals> <goal>stop</goal> <goal>build</goal> <goal>start</goal> </goals> </execution>

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      <executions> <execution>         <id>start</id> <phase>pre-integration-test</phase> <goals>                     <goal>stop</goal>     <goal>build</goal>     <goal>start</goal> </goals> </execution>

6. Now run this pom.xml using mvn clean install and check your docker containers so see if it running.

Here is the complete build section from the plugin, hope this help.