This sample application is archived. See https://github.com/lagom/lagom-samples for more example projects showcasing Lagom usage.
Lagom is a Swedish word meaning just right, sufficient. Microservices are about creating services that are just the right size, that is, they have just the right level of functionality and isolation to be able to adequately implement a scalable and resilient system.
Lagom focuses on ensuring that your application realises the full potential of the Reactive Manifesto, while delivering a high productivity development environment, and seamless production deployment experience.
This is a sample Java auction system using the Lagom Framework. A Scala version of the auction system is also available.
When you run the online auction, you access the interface with a browser. You can create user accounts and items for auction. Once the items are available, you can bid.
To download and run the online auction example you will need:
To use the online auction's search facility, you will also need Elasticsearch, which acts as the search database. You can run the example without Elasticsearch, but the search will not work.
To install sbt, refer to the content for your operating system (OS):
Download Elasticsearch server. For example, use a console that supports the curl
and tar
commands and enter the following commands one at a time:
curl -L -O https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.0.2.tar.gz
tar -xvf elasticsearch-5.0.2.tar.gz
To run the online auction example on your local machine:
Clone the online auction github repository to your local machine.
Open a terminal, change into the Elasticsearch bin
directory and start Elastic search. For example:
cd elasticsearch-5.0.2/bin
elasticsearch
Open another terminal and change to the top-level directory of the cloned online auction repository. For example:
cd online-auction-java
Run the sample app using the command sbt runAll
.
Open a browser and enter:
localhost:9000
To simulate an auction, you'll need to create at least two users and one item. Once created, you can bid on the item. By using different browsers, you can log in as different users and bid on the same item.
This project uses Lightbend Orchestration for Kubernetes to simplify deployment to Kubernetes.
Refer to KUBERNETES.md for more information on this process.
To get a better understanding of what can be done at each step of the application, inline instructions are displayed on the web UI. To disable these instructions, go to application.conf in the web-gateway micro-service and set online-auction.instruction.show to false.
The auction system is the sum of 5 micro-services and a web gateway:
user-service
as reference on how to create a secure user management micro-service.Check the docs for each service for details on the commands and queries it serves as well as events the service emits and events it consumes from the Message Broker.
Hello World seed: For a simple, gentler, introduction to Lagom with Java, have a look at the Hello World Lagom archetype using Maven or Giter8 lagom template with sbt.
Getting help: If you have any troubles and need help, feel free to ask in the Gitter channel