Over the years I have learnt to make smaller size docker images which have usually worked well for me and I have been able to reduce my image files from GBs in size to few hundred MBs. I recently found an article which summarizes these best practices in an easy to use approach.
Adding docker containerization support in a working Spring Boot application is surprisingly easy.
Step 1: Add the docker maven plugin to your pom file.
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>com.spotify</groupId>
<artifactId>dockerfile-maven-plugin</artifactId>
<version>1.3.4</version>
<configuration>
<repository>${project.artifactId}</repository>
</configuration>
</plugin>
</plugins>
</build>
Step 2: Build the application as well as the docker image
mvn clean package install dockerfile:build
Step 3: I have a local docker registry setup in my Lan so I prefer to push this image to my network registry manually (this can be automated as well however).
docker tag my-app:latest my_network_registry_host:5000/my-app
Step 4: Now we can bootup this docker image anywhere in the network.
docker run \ --detach \ --link <any database link> \ -e <Environment variable 1> \ -e <Environment variable 2> \ -p 8080:8080 \ --name my-app \ my_network_registry_host:5000/simply-hr
docker logs --follow simply-hr
In order to setup a fully functional Redmine server via Docker I use the following consolidated command:
docker run \ --detach \ --name redmine \ --link mysql:mysql \ --publish 3000:3000 \ --env="REDMINE_DB_MYSQL: redmine" \ --env="REDMINE_DB_PASSWORD: redmine" \ --volume /Volumes/DATA/Abhinav/Docker/redmine/files:/usr/src/redmine/files \ redmine
This connects my mysql docker instance with sonar and it is able to create tables and start using MySQL properly for storing all it’s data.
In order to setup a fully functional Sonarqube server via docker I use the following consolidated command:
docker run \
--detach \
--name=sonarqube \
--publish 9000:9000 \
--publish 9092:9092 \
--env="SONARQUBE_JDBC_USERNAME=sonar" \
--env="SONARQUBE_JDBC_PASSWORD=sonar" \
--env="SONARQUBE_JDBC_URL=jdbc:mysql://mysql:3306/sonar?useUnicode=true&characterEncoding=utf8&rewriteBatchedStatements=true" \
--link mysql:mysql \
sonarqube:5.1
This connects my dockerized mysql instance with sonar and it is able to create tables and start using MySQL properly for storing all it’s data.
In order to setup a fully functional MySQL server via docker I use the following consolidated command:
docker run \
--detach \
--name=mysql \
--env="MYSQL_ROOT_PASSWORD=abcd1234" \
--publish 6603:3306 \
--volume=~/Docker/mysql/conf.d:/etc/mysql/conf.d \
--volume=~/Docker/mysql/mysql-datadir:/var/lib/mysql \
mysql
The advantage of the above approach is that the configuration files can be defined under ~/Docker/mysql/conf.d folder on my system and it will be picked up whenever I bootup this instance. The second thing is that all information written by this instance will be stored outside of VM in the path ~/Docker/mysql/mysql-datadir on my system. So In case this VM goes away due to some unexplained reasons I can still bootup another docker instance of MySQL and point it to this data directory.