eazybytes/microservices: the code half of a paid Spring course

A code companion for a 20 section Udemy course

eazybytes/microservices is a Java repository that ships the code for a Udemy course titled Master Microservices with Spring Boot, Docker, Kubernetes. The project description calls it code examples, and that is exactly what it is. The teaching itself lives on the course page, linked from the repository home, while the repository holds the services, configuration and manifests that the course talks you through. The stated prerequisite is a good understanding of Java and Spring concepts, with basic Spring Boot and REST knowledge a bonus rather than a requirement. For the right reader, that pairing works: a Java developer who wants to see a service decomposition, a container image build and a Kubernetes manifest done in a specific way. For a reader without a Spring background, the code is readable but the reasoning behind the boundaries is missing.

One directory per course section, with several sections absent

The top level of the checkout is organised by course section: section2, section4, section6, section7, section8, section9, section_10, section_11, section_12, section_13, section_14, section_15, section_16, section_17 and section_20. The README lists twenty sections, and the names map onto the topics described there, so section_10 holds the resilience code, section_13 the RabbitMQ and Spring Cloud Stream work, section_14 the Kafka equivalent, section_15 the Kubernetes orchestration code, section_16 the Helm charts and section_17 the server side service discovery examples. Comparing the two lists is instructive, because the checkout has no directory for section3 on right sizing service boundaries, none for section5 on the 15 factor methodology, none for section18 on deploying into a cloud Kubernetes cluster and none for section19 on the Gateway API, Istio and mTLS.

The Maven command table is the shortest path to a running service

The repository does not install anything the way an application would, so the entry point is the Maven command table in the README. It lists four commands and the effect of each one:

mvn clean install -Dmaven.test.skip=true
mvn spring-boot:run
mvn spring-boot:build-image
mvn compile jib:dockerBuild

The first produces a jar inside the target folder, the second starts a Spring Boot project straight from source, and the last two produce a Docker image. The first use worth doing is to pick a section directory, run the install command to build that service, and then start it with the run command so you can confirm the service comes up before reading further. Note that the skip flag on the install command is deliberate, so a failing test in one service will not block you from exploring the others. The services depend on configuration and on infrastructure such as a database, so a clean start on the first run is not guaranteed, and the compose and container steps come next for that reason.

Three container image paths, two of them without a Dockerfile

The Docker table in the README covers the everyday lifecycle, from building an image to pushing it to a registry and inspecting running containers. A small slice of it:

docker build . -t eazybytes/accounts:s4
docker run -p 8080:8080 eazybytes/accounts:s4
docker image push docker.io/eazybytes/accounts:s4

The interesting part is the three competing ways to produce that image. The Dockerfile path is the familiar one, where docker build reads a file in the source tree. The Buildpacks path runs the spring-boot:build-image Maven goal and the table notes that no Dockerfile is needed. The Google Jib path runs the jib:dockerBuild goal with the same note, and the repository links to the Jib project for the details. The difference in approach is who decides the image layout: a Dockerfile puts the whole layout in the source tree, while the two plugin routes derive it from the build, which is why the course presents them as alternatives to hand written files rather than as one required method. Each of the three produces an image that the same docker run command starts.

Docker Compose is how the multi service picture comes together

Running one service is the easy half. The compose commands in the table are what turn the checkout into a system: docker compose up creates and starts containers based on the given Compose file, docker compose down stops and removes the containers, networks, volumes and images created by up, while start and stop operate on existing containers without recreating or removing them. The separation matters when you are working through a section that needs several services talking to each other, and it is why the course introduces Compose before it moves to Kubernetes, since the same mental model of declared services applies later with Helm. The distinction between up and start is the one that trips people up: a Compose file that you have edited does not take effect on a bare start, because start reuses what already exists.

The toolchain the course walks through, topic by topic

The value of this repository is that it names every moving part instead of assuming them. The link list in the README points at Spring Boot and start.spring.io for scaffolding, at Spring Cloud with its Config, Bus and Netflix components for configuration management and service discovery and registration, and at Spring Cloud Gateway for routing. Resilience is handled through Resilience4j, and the rate limiting section points at a Stripe blog on rate limiters. Data work is split between MySQL inside microservices and the DTO pattern with ModelMapper and MapStruct for mapping. Event driven sections cover RabbitMQ and Apache Kafka with Spring Cloud Functions and Spring Cloud Stream, observability is covered with Grafana, Micrometer and OpenTelemetry, and security with Keycloak. The Kubernetes end of the course uses Helm, a local cluster from Docker Desktop, k9s for cluster work, and the Spring Cloud Kubernetes project, with Istio and mTLS in the Gateway API section. Every one of those is a separate product to install and configure, and the repository keeps code for most of them in the section that introduces each one.

A Postman collection, an Apache-2.0 licence and no release history

Two smaller items sit alongside the service code. At the top level there is Microservices.postman_collection.json, a ready made collection for exercising the endpoints, which is the quickest way to check a service that has just started. The licence is Apache-2.0, so the code can be reused and modified with attribution and under the same notice obligations that the licence itself sets out, and the reader should read the LICENSE file rather than take a summary as legal guidance. The repository publishes no GitHub releases, and the default branch is 4.1.0, which is a course version rather than a library version. The last push was on 2026-10-15. Practically, that means there is no changelog to read and no tag to pin, so the sensible move is to check out the branch that matches the section of the course you are on, and to expect the code to drift from upstream Spring and Docker releases as those move on.

Editorial conclusion

The eazybytes/microservices checkout suits a Java developer who has bought the course and wants the working code beside the walkthrough, or a team that wants a reference implementation of the Spring Cloud and Kubernetes pieces the course covers. It does not suit a reader who wants a self contained guide, since the write-up assumes a good understanding of Java and Spring and the missing section directories leave gaps in the story. Verify three things before you commit to it: that the branch you check out matches the course version you are following, since the default branch is 4.1.0, that the section directory for the topic you need actually exists, and that the Maven and Docker commands in the table run against the version of Spring Boot and Docker you have installed. The last push was on 2026-10-15 and there are no GitHub releases, so treat the branch as the artifact you pin to.

Frequently asked questions

Official sources

1. eazybytes/microservices on GitHub
2. Issues
3. License: Apache-2.0
4. Project website
5. README