Distributed version of the Spring PetClinic Sample Application built with Spring Cloud

This microservices branch was initially derived from AngularJS version to demonstrate how to split sample Spring application into microservices. To achieve that goal we used Spring Cloud Netflix technology stack.

Starting services locally without Docker

Every microservice is a Spring Boot application and can be started locally using IDE or mvn spring-boot:run command. Please note that supporting services (Config and Discovery Server) must be started before any other application (Customers, Vets, Visits and API). Tracing server and Admin server startup is optional. If everything goes well, you can access the following services at given location:

• Discovery Server - http://localhost:8761
• Config Server - http://localhost:8888
• AngularJS frontend (API Gateway) - http://localhost:8080
• Customers, Vets and Visits Services - random port, check Eureka Dashboard
• Tracing Server (Zipkin) - http://localhost:9411
• Admin Server (Spring Boot Admin) - http://localhost:9090

You can tell Config Server to use your local Git repository by using local Spring profile and setting GIT_REPO environment variable, for example: -Dspring.profiles.active=local -DGIT_REPO=/projects/spring-petclinic-microservices-config

Start script

All services including the inspectIT Java Agent can be started with a start script:

Windows

Open a CMD and execute the script with the directory of the Java Agent: start_all_with_inspectIT.bat \path\to\Java\Agent. Additionally you can also set the InspectIT CMR host by passing in a second argument: start_all_with_inspectIT.bat \path\to\Java\Agent localhost. If no CMR host is provided localhost is used by default. The services can be stopped by closing the CMD.

Linux

Open a Terminal and execute the script with the directory of the Java Agent: start_all_with_inspectIT.sh \path\to\Java\Agent. Additionally you can also set the InspectIT CMR host by passing in a second argument: start_all_with_inspectIT.sh \path\to\Java\Agent localhost. If no CMR host is provided localhost is used by default. The services can be stopped by executing the following script: stop_all.sh

macOS

The macOS users need to first perform following commands (see vishnubob/wait-for-it#15) in order to solve the problem of missing timeout function on their OS:

brew install coreutils
alias timeout=gtimeout

Aside from this, the instructions should be same as for Linux users.

Starting services locally with docker-compose

In order to start entire infrastructure using Docker, you have to build images by executing mvn clean install -PbuildDocker from a project root. Once images are ready, you can start them with a single command docker-compose up. Containers startup order is coordinated with wait-for-it.sh script. After starting services it takes a while for API Gateway to be in sync with service registry, so don't be scared of initial Zuul timeouts. You can track services availability using Eureka dashboard available by default at http://localhost:8761.

JMeter load test

A JMX JMeter file for the Petclinic can be found inside the jmeter directory and is called pet_clinic_load_test.jmx. The JMX file can be parameterized with the following parameters and their default values inside the brackets:

• JHOST - The host of the system under test (localhost)
• JPORT - The port of the system under test (8080)
• JUSERS - The number of users (3)
• JRAMPUP - The rampup time in seconds (10)
• JINFLUXDB_HOST - The influx database host (localhost)
• JLOOPCOUNT - The number of iterations (30)
• JDURATION - The duration of the test in seconds (100)
• JDELAY - The delay of the thread creation in seconds (10000)

To start a JMeter load test use the following command:

jmeter -t jmx_file -n -JHOST="localhost" -JPORT="8080" -JUSERS=3

Understanding the Spring Petclinic application with a few diagrams

See the presentation here

You can then access petclinic here: http://localhost:8080/

In case you find a bug/suggested improvement for Spring Petclinic Microservices

Our issue tracker is available here: https://github.com/spring-petclinic/spring-petclinic-microservices/issues

Database configuration

In its default configuration, Petclinic uses an in-memory database (HSQLDB) which gets populated at startup with data. A similar setup is provided for MySql in case a persistent database configuration is needed. Note that whenever the database type is changed, the data-access.properties file needs to be updated and the mysql-connector-java artifact from the pom.xml needs to be uncommented.

You may start a MySql database with docker:

docker run -e MYSQL_ROOT_PASSWORD=petclinic -e MYSQL_DATABASE=petclinic -p 3306:3306 mysql:5.7.8

Looking for something in particular?

Spring Cloud components	Resources
Configuration server	Config server properties and Configuration repository
Service Discovery	Eureka server and Service discovery client
API Gateway	Zuul reverse proxy and Routing configuration
Docker Compose	Spring Boot with Docker guide and docker-compose file
Circuit Breaker	TBD
Graphite Monitoring	TBD

Front-end module	Files
Node and NPM	The frontend-maven-plugin plugin downloads/installs Node and NPM locally then runs Bower and Gulp
Bower	JavaScript libraries are defined by the manifest file bower.json
Gulp	Tasks automated by Gulp: minify CSS and JS, generate CSS from LESS, copy other static resources
Angular JS	app.js, controllers and templates

Contributing

The issue tracker is the preferred channel for bug reports, features requests and submitting pull requests.

For pull requests, editor preferences are available in the editor config for easy use in common text editors. Read more and download plugins at http://editorconfig.org.