Deploying Finovara on Docker and fixing a critical bug.

I recently decided to move my Spring Boot app Finovara to Docker.

At first it was just supposed to be a small improvement to the setup.
In reality, it turned into a debugging session that took way longer than I expected.

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Why I even bothered with Docker

There were a few reasons behind this:

• I wanted more control over the environment
• I needed a separate database (finovara-test) for automated tests
• I was tired of manually setting everything up locally
• and I wanted something closer to a real production setup

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Initial setup

I started with a simple PostgreSQL container and connected my app to it.

Here’s a simplified version of what I used:

services:
  finovara-db:
    image: postgres:15
    container_name: finovara-db
    restart: always
    environment:
      POSTGRES_DB: finovara
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: ${DB_PASSWORD}
    ports:
      - "5432:5432"
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U postgres"]
      interval: 5s
      retries: 10

Dockerfile:

FROM eclipse-temurin:21-jdk
WORKDIR /app
COPY target/*.jar app.jar
ENTRYPOINT ["java", "-jar", "app.jar"]

Everything started without issues.
Database was running, app connected, no errors.

So I thought I was done.

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The moment things got weird

I made some changes in the app, rebuilt everything, ran it again and nothing changed.

• same responses
• same data
• same behavior

At this point I was pretty sure I messed something up.

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What I thought vs what it actually was

My first guess was Docker caching.
Seemed like the obvious explanation.

But after digging a bit more, it turned out to be something else entirely.

The app was connecting to a completely different database than I expected.

Everything looked correct:

• same DB name
• same user
• same config

So from the outside it looked like everything was fine, but I was basically working on one database and checking another.

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Fixing it

The fix wasn’t one single thing, more like a combination of small adjustments:

• I changed the password in my .env file
• I changed the port, because something else was already using 5432
• I cleaned up and adjusted the docker-compose config
• and most importantly, I actually verified which database the app connects to

After that, everything finally made sense again and changes started showing up immediately.

Thanks for reading and visit my github!

M4rc1nek / finovara-backend

Backend service for a personal finance management application

Finovara

Backend platform for a personal finance management application, built with Java 25 and Spring Boot 4 as a set of microservices.

About the Project

Finovara is a personal finance platform designed to help users take full control of their money. The backend exposes a secure REST API that powers tracking of income and expenses, budget management, savings goals, shared accounts and financial reporting.

The platform is built as a set of independent services, each responsible for a separate area of the domain, so that individual parts of the system can be developed, deployed and scaled on their own. Security is a central concern: authentication is based on JWT, sessions are tracked per device, and user activity is recorded in an audit log.

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Key Features

Accounts and Security

• Authentication and Authorization - stateless JWT security built on Spring Security, with an access and refresh token flow.
• Device and Session Tracking…

View on GitHub