tiergarten-carmina

I present here a microservice-oriented demo of basic ZooKeeper functions. A dashboard allows to stop and start containerized instances of a service. This version uses Docker containers.

Here are the prerequisites for running the complete application:

A recent Linux version (I used Ubuntu 16.04)

A recent Apache Maven version installed (I used 3.3.9)

A recent Docker version installed (I used 17.12.1-ce)

1. Preparation

1.1 Images creation

In each of subdirectories: customer-server config-server eureka-server zuul-server

run the command: [sudo] mvn clean package docker:build.

It creates all Spring images. The non Spring image zookeeper will be pulled from a Docker repository.

1.2 JAR file creation

In subdirectory cluster-monitor run the command mvn clean package. This creates the JAR file needed for running cluster-monitor as a non containerized Spring Boot application.

2. Running the application

2.1 Running containers

To start the application go to docker subdirectory and run the command: [sudo] docker-compose up.

All running Spring containers can be seen on Eureka port 8761.

2.2 Running cluster-monitor

Wait for all containers to be up and running then in subdirectory cluster-monitor run the command mvn spring-boot:run. Note that cluster-monitor itself is not containerized.

Then connect to dashboard on localhost:8089 by clicking connect. It will return a display like:

Start some new containers by clicking Launch a new container. Wait to see the new container Ids appear like on this screen shot:

Then open a new browser window and enter this URI:

localhost:5555/api/customer/allCustomersWithContainer

It will return a display like:

Note that for each update the container Id changes in a round-robin way. Customer-server is a dummy server that display always the same response except for container Id.

To stop a container click the Stop.

Note that all customer server processes created keep running even if cluster-monitor itself is terminated.