This is part of a university course from University of the Aegean, aiming to provide students with practical experience on cloud technologies

Concept:

Java Spring Boot application that provides a simple RESTful API service for a DVD store. The API allows users to perform CRUD operations on a MySQL database containing DVD records. The application includes user authentication using Spring Security, and follows HATEOAS principles for API design. It also includes Docker for containerization and can be run on a minikube created Kubernetes cluster.

Associated DockerHub container repository: https://hub.docker.com/r/ttomtsis/dvd-spring-server

• Role-based authorization, Basic Authentication
• HATEOAS
• Docker support
• Kubernetes support
• MySQL and MySQL Operator with InnoDB cluster
• GraalVM Native Image and executable
• TLS v1.3 support with dummy certificates

• Java 17
• Spring Boot 3.0.5
• Spring Security 6
• MySQL 8.0
• HATEOAS 3
• Docker
• Kubernetes
• GraalVM 22

To get started with this project, you can choose either to run it locally on your host machine, on docker or in a single node Kubernetes cluster using minikube.

You will need to have the following installed on your machine:

• Java 17+
• Maven 3.9.1+, or you can use the provided maven wrapper
• MySQL Server installed or running in a container ( Unless the default H2 database suits your needs ).

The spring boot app consists of two profiles similar to each other:

1. The 'default profile' should be used for local development and testing. Used an H2 database unless configured otherwise and lacks more advanced features spring actuator.

2. The 'containerized profile' should be used when the application is containerised in docker, deployed in Kubernetes or if running as a native image or executable. It is similar to the default profile but contains some extra properties ( i.e. graceful shutdown ). Set the active profile in windows powershell: $env:SPRING_PROFILES_ACTIVE="containerized"

A dummy root CA certificate is provided in the resources/tls directory. You can install this in your system. There is also a server certificate provided, which has been signed by the dummy CA. Feel free to replace those certificates as needed. The scripts used below were created for the Windows OS.

To use a normal database you must configure the application to use your credentials when connecting to the specified database by setting the following environment variables:

• DB_USERNAME : The username that you use when you connect to the database
• DB_PASSWORD : The password that you use when you connect to the database
• DATASOUCE_URL : The url pointing to the location of your database, either local or remote.

You can use the provided certificates or you can override the following properties, via environment variables, to implement your own configuration

• server.ssl.key-store : The location of the keyfile
• server.ssl.key-store-password : The password required ( if required ) in order to access the key file
• server.ssl.key-store-password : The type of the keyfile
• server.ssl.keyAlias : The alias associated with the key file

To build and run the project using maven, follow these steps:

• Clone the repository to your local machine: git clone https://github.com/ttomtsis/DVDApplication
• Navigate to the project directory
• Build the project: mvn clean install
• Run the project: mvn spring-boot:run

NOTE: You can also use the provided maven wrapper

You can also download the latest native executable ( https://github.com/ttomtsis/DVDApplication/releases ), configure it as described above and run it without any prerequisites

To run the project on Docker, make sure you have Docker installed on your machine.

• Clone the repository to your local machine git clone https://github.com/ttomtsis/DVDApplication
• Navigate to the project directory
• Run the setup.bat file.This will create a Docker image for the application: ./setup.bat
• Navigate to the docker-scripts directory
• Start the containers by running the start.bat file: ./start.bat
• Stop the containers and remove them along with the images,networks and volumes by running the stop.bat file: ./stop.bat

• Clone the repository to your local machine git clone https://github.com/ttomtsis/DVDApplication
• Navigate to the docker-scripts directory, located inside the project directory
• Start the containers by running the compose-start.bat file: ./compose-start.bat
• Delete the containers, networks and associated volumes by running the compose-stop.bat file: ./compose-stop.bat

• Check out the associated dockerhub repository: https://hub.docker.com/repository/docker/ttomtsis/dvd-spring-server/general
• Pull the desired image and use the start.bat script to run it docker pull ttomtsis/dvd-spring-server:latest

NOTE: If you pull a tag other than 'latest' you will need to tag the pulled image to 'dvd-spring-server:latest' in order for the script to work properly

To run the project on Minikube, you can use either the provided python scripts or create the cluster manually. Make sure you have python 3, minikube and kubectl installed and properly configured on your machine. You will also need to install the MySQL Operator and have the 'awk' cli utility installed ( this process will be automated in the future, the awk utility is required for the deletion script to function ).

For info on how to install the MySQL Operator refer to its official GitHub repository:

https://github.com/mysql/mysql-operator

• Clone the repository to your local machine: git clone https://github.com/ttomtsis/DVDApplication
• Navigate to the 'kubernetes' folder in the project directory
• Run the setup.py file. This script initializes a minikube cluster with a REST server, and an InnoDB Cluster with 3 databases
• Get the minikube IP address. Keep this window open.
• Access the application's endpoints at the given IP address
• If you want to remove all traces of the application run the delete.py script

Open a terminal inside the 'kubernetes' folder and follow the sequence of steps provided below:

1. Create the config map kubectl apply -f ./configs/dvd-conf.yaml
2. Create the secret kubectl apply -f ./database/db-secret.yaml
3. Create the persistent volume and claim the InnoDB cluster will use for backups kubectl apply -f ./database/innodb-backup.yaml
4. Create the InnoDB cluster kubectl apply -f ./database/innodb-cluster.yaml
5. Initialize the InnoDB cluster kubectl apply -f ./database/init-cluster.yaml
6. Wait for the cluster's creation
7. Create the rest server's service kubectl apply -f ./rest-server/rest-server-service.yaml
8. Create the rest server's deployment kubectl apply -f ./rest-server/rest-server-deployment.yaml
9. Wait for the rest server to fully initialize ( When using a native image this won't take more than 1 second )
10. Use minikube to expose the rest server minikube service rest-server-service

DVD CRUD Operations

• GET /api/dvds - Retrieves a list of all DVDs.
• GET /api/dvds?name=dvdName - Retrieves a list of DVDs that match the specified title.
• GET /api/dvds/{dvdID} - Retrieves details about a specific DVD.
• POST /api/dvds - Adds a new DVD to the database.
• PUT /api/dvds/{dvdID} - Updates the quantity and genre of an existing DVD.
• DELETE /api/dvds/{dvdID} - Deletes a DVD from the database.

Actuator

NOTE: If the server is running as a native image or executable, only the /server/health and /server/logs endpoints are available.

• GET /server - Provides a list of all actuator endpoints
• GET /server/info - Returns basic information about the application
• GET /server/mappings - Provides an exhaustive list and description of all the endpoints
• GET /server/logs - Returns the contents of the servers logfile
• GET /server/beans - Returns an exhaustive list and description of the application's beans
• GET /server/health - Return the server's running state
• GET /server/health/{*path} - Provides information for the specified custom health metric
• GET /server/env - Provides a list of all spring configured properties
• GET /server/env/{toMatch} - Returns information about the specified property
• GET /server/loggers - Provides a list of all available loggers
• GET /server/loggers/{name} - Returns the logging level of a specific logger
• POST /server/loggers/{name} - Change the configuredLevel of the specified logger
• GET /server/metrics - Provides a list of the supported application metrics
• GET /server/metrics/{MetricName} - Returns the value of the specified metric