Converter Service

This is an example or a bit more complex 'hello world' try-out to package a fully-executable Spring Boot application as Debian package so that it could be installed at any Debian derived Linux distribution such as Ubuntu. It will be installed as a systemd service and can be controlled using service converter start or service converter stop. Status information are available with service converter status.

It uses the Jackson library as defined by Spring Boot to do the conversion between JSON and YAML.

The following endpoints are available:

• http://localhost:8080/actuator reveals some runtime information such as health check, thread dump or some basic metrics.
• http://localhost:8080/json2yaml accepts POST and converts the body from a JSON to YAML
• http://localhost:8080/yaml2json accepts POST and converts the body from a YAML to JSON

Build

To build the project run Maven:

mvn package

Run stand-alone

After build change into the target directory and just execute the jar file:

cd target
./convert-<VERSION>.jar

Requires an installed JVM such as OpenJDK 8 with the environement variable JAVA_HOME set accordingly.

Installation of deb

To install the Debain package:

sudo dpkg -i converter-<VERSION>.deb

The deb-package requires an installed Java distribution such as OpenJDK 8 which will be resolved by the package manager.

The following directories are used:

• /var/log/converter contains the log files
• /var/run/converter conatins runtime data such as the pid file and the Apache Tomcat's work directory
• /etc/converter contains the configuration
• /usr/lib/converter contains the fully-executable Spring Boot fat jar file

A technical user converter will be created to run the systemd service.

Deinstallation of deb

 sudo apt remove converter-<VERSION>

See also

• Spring Boot tutorial: https://spring.io/guides/gs/spring-boot/
• JDeb: https://github.com/tcurdt/jdeb