Open Source Ecosystems

= Digital Library

This project implements a basic digital library with searching books via ISBN and inventory management (add/delete book) functions using link:https://spring.io/projects/spring-modulith[Spring Modulith,window=_blank] and ReactJS. This application uses link:https://openlibrary.org/[Open Library,window=_blank] as book info database. The project supports Java SDK 21.

See Medium article: https://medium.com/@selcuk.sert/modular-monoliths-with-spring-modulith-96361f3167c9[Modular Monoliths with Spring Modulith ]

[cols="a,a"] |=== | image:docs/images/ui-1.png[ui-1] | image:docs/images/ui-2.png[ui-2] |===

== Architecture

The project is compatible with docker and comprises of modules and services that underpins a typical Spring Modulith based application:

image:docs/models/arch.png[arch]

=== Traefik

Serves as edge router for docker-compose setup.

=== Neo4J

Serves as event registry for digilib modulith. It includes Neo4J browser for data browsing on graph DB.

=== Kafka

Serves as message broker for event externalization. Kafdrop is used as event browser.

=== PostgreSQL

Serves as relational database to store book inventory. PgAdmin is used as DB viewer.

=== Zipkin

Is used to capture and view micrometer spans originated by digilib modulith for telemetry and tracing.

== Start-up Modes

The project comes with two different modes based on docker-compose:

One for link:docker/docker-compose.yml[development] to activate mandatory external services for development with opening required ports for IDE,
The other one for link:docker/docker-compose.yml[production] complementing previous one with serving full-stack application inside docker-compose setup.

The link:docker/start.sh[start script] (based on zsh) has the following options:

[source,shell]

start.sh -h

[source,text]

Start script for digilib app

Syntax: start.sh [-h|p|d]
options:
h Prints this Help.
p Start in production mode.
d Start in developer mode.
u Uninstall setup.

The start script also generates (under certificates folder) and registers a self-signed certificate (public certificate and private key) to enable TLS on Traefik edge router. The digilib.crt should be imported into trusted CA list for seamless browsing.

See link:docker/.env[environment file] for credentials and parameters used in docker-compose setup.

=== URLs

Some DNS entries should be added with IP of node that hosts Traefik deployment. For local deployments a typical hosts file content for digilib would be: