scaling-docker-example

This project demonstrates a scale out of a java web application using Docker, Tomcat as the java application server and Nginx to handle the incoming requests and redirect to one of the java webapp replic;

The project is divided in three modules;

• dac-exemplo-shared that will contain all the shared classes between the modules below;
• dac-exemplo-jse that is a jse application that communicates to the database to list the persisted clients;
• dac-exemplo-web that is a web application that communicates to the database to list the persisted clients;

Requirements

• JDK8
• Maven
• Docker
• Docker-Compose

Make sure you have the softwares above installed on your machine.

Deploying

• First of all, you need to create the network cliente-default defined in the docker-compose.yaml file. Do that by running the command sudo docker network create cliente-default
• You need to compile the source code and install these applications in your maven local repository. You can do this by running the command: mvn install
• Now you have to create all the images defined in the dockerfiles. You can do this by running the command: sudo docker-compose build
• Now let's scale our container based on the web application image. Let's create 5 replics. To do that run the command: sudo docker-compose scale web=5
• Finally, run the command sudo docker-compose up -d to start our containers;

Accessing the java webapp

After complete the steps above, you can access the java webapp by the address: http://localhost:83/exemplo-primeira-aula/cliente

PS: If the port 83 is being used by some service in your machine, just replace the port in the file docker-compose.yaml