Microservices-Sample-using-SpringBoot-SpringCloud-Eureka-and-Zuul

Spring Cloud project shows how to create simple microservices with Spring Boot, Spring Cloud, Eureka (Discovery Server) and Zuul (API gateway, Proxy, Load balancer)

Table of contents

• Architecture
• Technologies
• Getting Started
• Sample Requests
• About me
• Acknowledgments

Architecture

The project follows the microservices architectural style as in the next diagram

We have three independent microservices (User, Site, Organization), which register themself in service discovery (Eureka Server), and communicate with each other by declarative REST client (Open Feign). The whole system is hidden behind API gateway (Zuul).

Technologies

This project is created using the following technologies:

1. Java 8

2. Spring Boot in cloud-native development:

   • Spring Cloud Netflix Eureka – Registration and Discovery service for all microservices
   • Spring Cloud Netflix Zuul – API Gateway service that provides dynamic routing, and load balancer
   • Spring Cloud Netflix Feign – Declarative REST client

3. Spring Boot in microservices development:

   • Spring Web
   • Spring Data JPA
   • Spring Devtools
   • Spring Actuator
   • H2 In-Memory database

4. Maven Dependency Management

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes. See deployment for notes on how to deploy the project on a live system.

Prerequisites

You need to install the following software:

• Java JDK 1.8+
• Maven 3.0+

Developing Steps

The steps to be taken in order to create working microservices-based system using Spring Cloud:

Step 1. Creating service discovery with Spring Cloud Netflix Eureka

Step 2. Building the microservices using Spring Boot, Spring Cloud and communication between them with Spring Cloud Open Feign:

• User microservice
• Site microservice
• Organization microservice

Step 3. Creating API gateway using Spring Cloud Netflix Zuul

Step 4. Running and testing applications

Setup

To run this project, install it locally as follow:

1. Clone the application

   git clone https://github.com/SayedBaladoh/Microservices-Sample-using-SpringBoot-SpringCloud-Eureka-and-Zuul.git

2. Change the servers' port for the applications as per you want

   Each application will start at the server on the port as specified in the previous architecture diagram by default. If you want to change the default port for the discovery service and the microservices

   • open src/main/resources/application.properties file
   • change server.port property

   For the API Gateway service you can change the default port

   • open src/main/resources/application.yml file
   • change server.port property

3. Run the service registry and discovery application

   You can run the discovery service by typing the following command

   cd discovery-service
   mvn spring-boot:run

   The server will start on port 8761 by default, So once you have successfully started application you'll be able to visit the Eureka dashboard under address http://localhost:8761.

   If you changed the port in src/main/resources/application.properties file, use your custom port http://localhost:port.

4. Run the User microservice application

   You can run the user microservice by typing the following command

   cd user-service
   mvn spring-boot:run

   The user microservice will start on port 8081 by default, So you'll be able to visit the user microservice under address http://localhost:8081.

   If you changed the port in src/main/resources/application.properties file, use your custom port http://localhost:port.

   But we will use the address of Zuul API Gateway as a routing address for all microservice requests.

5. Run the Site microservice application

   You can run the site microservice by typing the following command

   cd site-service
   mvn spring-boot:run

   The site microservice will start on port 8082 by default, So you'll be able to visit the site microservice under address http://localhost:8082.

   If you changed the port in src/main/resources/application.properties file, use your custom port http://localhost:port.

   But we will use the address of Zuul API Gateway as a routing address for all microservice requests.

6. Run the Organization microservice application

   You can run the organization microservice by typing the following command

   cd organization-service
   mvn spring-boot:run

   The organization microservice will start on port 8083 by default, So you'll be able to visit the organization microservice under address http://localhost:8083.

   If you changed the port in src/main/resources/application.properties file, use your custom port http://localhost:port.

   But we will use the address of Zuul API Gateway as a routing address for all microservice requests.

7. Run the API gateway application

   You can run the Zuul API gateway service by typing the following command

   cd gateway-service
   mvn spring-boot:run

   The server will start on port 8080 by default, So once you have successfully started application you'll be able to visit API gateway under address http://localhost:8080.

   If you changed the port in src/main/resources/application.yml file, use your custom port http://localhost:port.

   Zuul API Gateway will forward the request to the specific microservice based on its proxy configuration. Such request will also be load balances by ribbon client.

8. Package the applications

   You can also package the applications in the form of a jar file and then run each application like so

   cd service_directory
   mvn clean package
   java -jar target/service_name-0.0.1-SNAPSHOT.jar

   • service_directory: the directory of the service.
   • service_name: the name of the service.

9. Run additional instances from microservices

   You can run more instances of the microservices (User, Site, Organization):

   • Using eclipse just edit run command of your application (Run configurations…) and add VM parameter -DPORT=… or -Dserver.port=….

   • Or using the -Dserver.port=… argument with the command: java -jar target/service_name.jar -Dserver.port=…

   java -jar target/service_name-0.0.1-SNAPSHOT.jar -Dserver.port=8085

Running

To access the applications use the following endpoints

• Eureka Discovery Service

  After running discovery-service, its monitoring console available on 8761 port.

  http://localhost:8761

  

  Now take a look on Eureka monitoring console: We’ve got one instance of Site and Organization microservices running on default ports (8082, 8083) and two instances of user microservice on (8081, 8085) ports registered on discovery server.

• API Gateway and Microservices

  • View info about API Gateway service http://localhost:8080/actuator/info

  • Check Health for API Gateway service http://localhost:8080/actuator/health

  Zuul is configured to be available under its default port 8080 and it forwards requests:

  • From /api/users/ path to user-service
  • From /api/sites/ path to site-service
  • From /api/organizations/ path to organization-service

  When URL http://localhost:8080/api/users/1 is called several times the Zuul make load balanced between two instances of each user microservice instances. Also when we shut down one of microservice instance we can take a look that it is unregistered from Eureka server dashboard.

Sample Requests

CURL GET command samples for different (User, Site, Organization) microservices using Zuul API Gateway address:

User APIs

• Display info about User microservice

   curl -X GET \
   'http://localhost:8080/api/users/actuator/info' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

• Check Health for User microservice

   curl -X GET \
   'http://localhost:8080/api/users/actuator/health' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

• List all users

   curl -X GET \
   'http://localhost:8080/api/users' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

• Find user by Id

   curl -X GET \
   'http://localhost:8080/api/users/1' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

• Filter users by SiteId

   curl -X GET \
   'http://localhost:8080/api/users/site/3' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

• Filter users by OrganizationId

   curl -X GET \
   'http://localhost:8080/api/users/organization/1' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

Site APIs

• Display info about Site microservice

   curl -X GET \
   'http://localhost:8080/api/sites/actuator/info' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

• Check Health for Site microservice

   curl -X GET \
   'http://localhost:8080/api/sites/actuator/health' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

• List all sites

   curl -X GET \
   'http://localhost:8080/api/sites' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

• Find site by Id

   curl -X GET \
   'http://localhost:8080/api/sites/1' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

• Filter sites by OrganizationId

   curl -X GET \
   'http://localhost:8080/api/sites/organization/1' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

• Filter sites with users by OrganizationId

   curl -X GET \
   'http://localhost:8080/api/sites/organization/1/with-users' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

Organization APIs

• Display info about Organization microservice

   curl -X GET \
   'http://localhost:8080/api/organizations/actuator/info' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

• Check Health for Organization microservice

   curl -X GET \
   'http://localhost:8080/api/organizations/actuator/health' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

• List all organizations

   curl -X GET \
   'http://localhost:8080/api/organizations' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

• Find organization by Id

   curl -X GET \
   'http://localhost:8080/api/organizations/1' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

• Find organization with sites by Id

   curl -X GET \
   'http://localhost:8080/api/organizations/1/with-sites' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

• Find organization with sites and users by Id

   curl -X GET \
   'http://localhost:8080/api/organizations/1/with-sites-with-users' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

• Find organization with users by Id

   curl -X GET \
   'http://localhost:8080/api/organizations/1/with-users' \
     -H 'accept: */*' \
     -H 'cache-control: no-cache'

About me

I am Sayed Baladoh - Phd. Senior Software Engineer. I like software development. You can contact me via:

• LinkedIn+
• Mail
• Phone +20 1004337924

Any improvement or comment about the project is always welcome! As well as others shared their code publicly I want to share mine! Thanks!

Acknowledgments

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