Container-Automat Factory

A generator for examples of service-oriented applications

Container-Automat is a generator of service-oriented applications for demonstration purposes that are based on Deterministic Finite Automata (abbreviated DFA).

The DFA is used to simulate the application logic of a service-oriented application. In addition to the application-specific components, the application also contains a message broker, a database, and optional components for logging the processing of requests. So relatively complex conglomerates of services are possible.

The idea behind the Container-Automat project is to be able to easily generate sample applications

• to explore the interaction of services in Docker containers.
• in order to gain experience with a message broker or a database.
• that can serve as a starting point for showcases or prototypes.

Quickstart

Step 1: Build a Docker image for the factory application.

container-automat> builddocker-container-automat-factory.cmd

Step 2: Run a Docker container with the factory application.

container-automat> rundocker-container-automat-factory.cmd

Step 3: Open the factory UI in a browser with the following URL.

http://localhost:9999/v1/dfa-editor.html

Note: There are corresponding .sh files for Linux for the Windows .cmd files mentioned.

Features of generated applications

• The application as a whole implements the DFA.
• For each state of the DFA there is a service, which is implemented in Java with Spring Boot.
• Requests are received in the form of input strings for the DFA via a REST interface.
• For state transitions, commands are sent to the service of the target state using a message broker.
• Processing can be logged using events also sent via the message broker.
• Optionally, these events can be processed with Elasticsearch, Logstash, and Kibana.
• Information about requests and processing steps is stored in a database.
• Both the message broker and the database can be selected from several systems.
• The message broker, the database, and the optional ELK services are started in Docker containers.
• The Java programs for the states of the DFA can be started both locally and in Docker containers.
• The entire application can be executed as a cluster with Docker Compose.

Requirements

• Docker
• Java JDK 21
• Spring Boot 3.2.3
• Maven 3.9.6

Building and launching the Factory with Docker

The Dockerfile container-automat-factory.dockerfile in the root directory of the factory project can be used to create a Docker image that contains a Java runtime and the factory application.

To start the Docker build process, the project directory contains both a CMD file for the Windows command prompt and an SH file for the Linux shell.

# Build the Docker image of the factory under Windows.
container-automat> builddocker-container-automat-factory.cmd

# Build the Docker image of the factory under Linux.
container-automat$ ./builddocker-container-automat-factory.sh

This is a multi-stage Docker build process in which a Maven base image is used in the first stage to build the application directly from the Java source, so that neither Maven nor a JDK needs to be available on the local system.

Once the build process is complete, a Docker container with the factory app can be started by calling the following CMD file under Windows or SH file under Linux. (These files are also located in the root directory of the project.)

# Start a Docker container with the factory under Windows.
container-automat> rundocker-container-automat-factory.cmd

# Start a Docker container with the factory under Linux.
container-automat$ ./rundocker-container-automat-factory.sh

The HTML UI of the factory application can then be called up locally under port 9999 in a browser with the following URL:

http://localhost:9999/v1/dfa-editor.html

The following commands can be used to stop and restart the Docker container with the factory app:

docker stop container-automat-factory
docker start container-automat-factory

For details on how Docker containers work in general, please refer to the Docker documentation or relevant literature.

Documentation

The factory source code contains only a few comments. Essentially, it should speak for itself. More information about the use of the Container-Automat Factory, about the examples of deterministic finite automata it contains, and about the Container-Automat project in general can be found on the project website at:

www.container-automat.de

License

The Container-Automat Factory is open source software licensed under the Apache License, Version 2.0. You may obtain a copy of the license at:

https://www.apache.org/licenses/LICENSE-2.0