senseiwu / microservices

Training examples

microservices - DRAFT

service-registration

generate service skeleton

goto: http://start.spring.io/ and in field Search for dependencies type:

Cloud Boostrap, Web, Eureka Server

add configuration

eureka:
  instance:
    hostname: localhost
  client:
    registerWithEureka: false
    fetchRegistry: false

server:
  port: 1111

edit main class

add annotation to make this service discovery server

@EnableEurekaServer

account-service

generate service skeleton

goto http://start.spring.io/ and add dependencies (see Search for dependencies field):

Client Config, Cloud Bootstrap, Eureka Discovery

add configuration

spring:
  application:
    name: account-service

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:1111/eureka/

server:
  port: 2222

edit main class

add annotation to make this service discoverable be Eureka

@EnableDiscoveryClient

Circuit braker

Warm up: https://spring.io/guides/gs/circuit-breaker/

FAQ

EMERGENCY! EUREKA MAY BE INCORRECTLY CLAIMING INSTANCES ARE UP WHEN THEY'RE NOT. RENEWALS ARE LESSER THAN THRESHOLD AND HENCE THE INSTANCES ARE NOT BEING EXPIRED JUST TO BE SAFE

• spring-cloud/spring-cloud-netflix#1195
• spring-cloud/spring-cloud-netflix#1322

Could not autowire field:RestTemplate in Spring boot application

• http://stackoverflow.com/questions/36151421/could-not-autowire-fieldresttemplate-in-spring-boot-application

Microservices - RestTemplate UnknownHostException

• http://stackoverflow.com/questions/37159662/microservices-resttemplate-unknownhostexception

rest POST

Bean must have default constructor and setters, otherwise it can't find proper constructor - find out why.

Post JSON to spring REST webservice

• http://www.leveluplunch.com/java/tutorials/014-post-json-to-spring-rest-webservice/

Links

• Microservices: http://www.martinfowler.com/articles/microservices.html
• Microservices: http://www.martinfowler.com/microservices/
• Microservices with spring: https://spring.io/blog/2015/07/14/microservices-with-spring
• Microservice Registration and Discovery with Spring Cloud and Netflix's Eureka: https://spring.io/blog/2015/01/20/microservice-registration-and-discovery-with-spring-cloud-and-netflix-s-eureka
• Microservices: http://microservices.io/
• Spring Boot Reference Guide: http://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/
• Spring Cloud Netflix: http://cloud.spring.io/spring-cloud-netflix/spring-cloud-netflix.html
• Ribbon: http://cloud.spring.io/spring-cloud-netflix/spring-cloud-netflix.html#spring-cloud-ribbon
• Service Registration and Discovery: https://spring.io/guides/gs/service-registration-and-discovery/
• Building REST services with Spring: https://spring.io/guides/tutorials/bookmarks/
• Edit wiki guide: https://help.github.com/categories/writing-on-github/

Licence

MIT License

Copyright (c) [2016] [Tomasz Kozlowski]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.