Automatic update spring boot docker app using ansible - spring-boot

Question

We plan to release spring boot application to customer. In corrent process, every time we release a new version, we have to uninstall the rpm and re install using rpm.
We want to move towards auto update of our application whenever there is a new version available. Essentially customer does not have to deal with updating the applications.
Instead of rpm, we are thinking about docker image, packaged with all dependencies.
. How do achieve this functionality?
Based on what I have read so far, if we package we use ansible + docker to deploy the application, , ansible (using watch tower or custom code) will ping an IP and when discovers a new version, will stop the application, pull the application from destination and then deploy and start.
Is my understanding correct?

Answer 1

Steps to automate deployment
Docker
Create application and dockerise it with any JDK docker image. We have maven package to dockerise application.
Add Plugin to pom.xml
<plugin>
<groupId>com.spotify</groupId>
<artifactId>docker-maven-plugin</artifactId>
<version>0.4.10</version>
<configuration>
<imageName>job-demand-service-analytics-processor</imageName>
<dockerDirectory>src/main/docker</dockerDirectory>
<resources>
<resource>
<targetPath>/</targetPath>
<directory>${project.build.directory}</directory>
<include>${project.build.finalName}.jar</include>
</resource>
</resources>
</configuration>
</plugin>
OR
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>com.google.cloud.tools</groupId>
<artifactId>jib-maven-plugin</artifactId>
<version>${jib-maven-plugin.version}</version>
<configuration>
<from>
<image>adoptopenjdk:11-jre-hotspot</image>
</from>
<to>
<image>websockethandler:latest</image>
</to>
<container>
<entrypoint>
<shell>sh</shell>
<option>-c</option>
<arg>chmod +x /entrypoint.sh && sync && /entrypoint.sh</arg>
</entrypoint>
<ports>
<port>8090</port>
</ports>
<environment>
<SPRING_OUTPUT_ANSI_ENABLED>ALWAYS</SPRING_OUTPUT_ANSI_ENABLED>
<APP_SLEEP>0</APP_SLEEP>
<JWT_SECRET_KEY_BASE64>""</JWT_SECRET_KEY_BASE64>
..........
</environment>
<useCurrentTimestamp>true</useCurrentTimestamp>
</container>
</configuration>
</plugin>
</plugins>
There are many options to dockerise your Spring application
Git
Push your code to git server like Bitbucket, Gitlabs, Github and so on.
Create a master branch for production releases and develop branch for development.
Jenkins
Trigger a jenkins job to create a docker image when you commit or merge changes from develop to master when feature is commited to develop.This is based on the hooks we add at git server.
If the docker image created successfully trigger the job which deploys.
Reverse Proxy or Load Balancer
To achive zero downtime, use load balnacer(reverse proxy like NGINX with upstream) running your container in multiple replicas of the container.
This applies for any application. If you have special requirement, update your question with the basic example code and will update the answer with Dockerising and automation steps.