This document discusses strategies for modernizing a legacy monolithic application, including using strangler patterns to gradually refactor the monolith into microservices. It outlines approaches like using an API gateway to front the legacy system and new services, as well as methodologies like twelve-factor apps. Key techniques mentioned include feature toggles and service discovery with Eureka.

3. ✔
✔ (customizing)
✔ , 5
✔ (Amazon Web Service)

4. legacy.php {
HTML
+= CSS
+= JAVASCRIPT
+= PHP
+= SQL
}

6. STRANGLER FACADE
LEGACY
MODERN
STRANGLER FACADE
MODERN
LEGACY
MODERN
STRANGLER FACADE

7.


Backend
Frontend

8. Embedded servlet containers(undertow.io)
jOOQ 3.xSpring MVC 4.x
Spring Boot 1.5.x, Spring Framework 4.x, Spring Cloud AWS 1.2.x

BackendAWS Elastic Beanstalk / JVM(Java 1.8)
Presentation Application
Business (Domain)
Data Access

9. 
Backend
Frontend


10.


Backend
Frontend

11. RPC Stub RPC Server
SHARED
LIBRARY

12. HTTP Client HTTP Server
- (RESOURCE) - URI
- (Verb) - HTTP Method
- (Representations)

13. TWELVE-FACTOR APP METHODOLOGY

14. .
.
.
.
, , .
(Codebase): .
(Dependencies): .
(Config): .
(Backing services): .
, , (Build, Release, Run): , .
(Processes): .
(Port binding): .
(Concurrency): .
(Disposability): .
/ (Dev/Prod parity): , .
(Logs): .
(Admin Process): (admin/management) .

15. Backend
Frontend

function getUsableMileage(){
if (FeatureToggle::create()->isEnable(FeatureToggle::USE_BE_MILEAGE)) {
// Backend
}
//
return $usable_mileage;
}
https://martinfowler.com/articles/feature-toggles.html


16. 
API GATEWAY
Backend
Frontend


18. Eureka Client
(service discovery)
Ribbon
(load balancer)
Zuul Proxy
(edge service)
Eureka Server
Hystrix Dashboard,
Turbine
Hystrix
(circuit breaker)

19. http://woowabros.github.io/experience/2017/08/21/hystrix-tunning.html

21. http://woowabros.github.io/experience/2018/06/07/vue-story-of-baminchan.html

22. 
API GATEWAY
Backend
Frontend
. .

23. legacy.php {
require_once '/common/config.php';
require '/common/init.php';
include 'header';
include 'view';
include 'footer';
}
Frontend

24. 
API GATEWAY

25. 
API GATEWAY

26. 
API GATEWAY

27. babel(ES6), sass, webpack
Node.js v8.x
http-proxy, requestExpress.js, Handlebars
Vue.js v2.x axios
gradle, babel(ES6), sass, webpack
Java 1.8, Node.js v8.x
Spring Cloud NetflixSpring MVC, Thymeleaf
Vue.js v2.x axios
Spring Boot 1.5.x

28. babel(ES6), sass, webpack
Node.js v8.x
http-proxy, requestExpress.js, Handlebars
Vue.js v2.x axios
gradle, babel(ES6), sass, webpack
Java 1.8, Node.js v8.x
Spring Cloud NetflixSpring MVC, Thymeleaf
Vue.js v2.x axios
Spring Boot 1.5.x

29. babel(ES6), sass, webpack
Node.js v8.x
http-proxy, requestExpress.js, Handlebars
Vue.js v2.x axios
gradle, babel(ES6), sass, webpack
Java 1.8, Node.js v8.x
Spring Cloud NetflixSpring MVC, Thymeleaf
Vue.js v2.x axios
Spring Boot 1.5.x

30. https://github.com/arawn/continual-improve-legacy-web

31. ORDER
SYSTEM
[ WEB ]
USER-SERVICE
API GATEWAY
PRODUCT
SYSTEM
SCM
SYSTEM
EXTERNAL
SYSTEMS
MDM
SYSTEM[ WEB ]
BACK-OFFICE

33. ORDER
SYSTEM
[ WEB ]
USER-SERVICE
API GATEWAY
PRODUCT
SYSTEM
SCM
SYSTEM
EXTERNAL
SYSTEMS
MDM
SYSTEM[ WEB ]
BACK-OFFICE

34. ORDER
SYSTEM
PRODUCT
SYSTEM
SCM
SYSTEM
EXTERNAL
SYSTEMS
MDM
SYSTEM
local.baeminchan.com
dev.baeminchan.com
test.baeminchan.com
staging.baeminchan.com
production.baeminchan.com

35. local.baeminchan.com
dev.baeminchan.com
test.baeminchan.com
staging.baeminchan.com
production.baeminchan.com
Application
Code
https://12factor.net/config

36. └── resources
├── application.yml #
├── application-local.yml #
├── application-dev.yml #
├── application-test.yml #
├── application-staging.yml #
├── application-production.yml #
└── application-ec2.yml # AWS EC2
> java -jar application.jar --spring.profiles.active=dev,ec2
+ OS environment variables (AWS Elastic Beanstalk) {
export DB_USERNAME="order_service"
export DB_PASSWORD="7%wo9;ttArRYMfYp"
}
https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-external-config.html

37. AWS Elastic Beanstalk
{ WEB UI }
AWS EC2
{ SSH }
AWS LAMBDA
{ WEB UI }
WEB
APP
BATCH
APP
SERVERLESS
APP

38. https://projects.spring.io/spring-cloud/

39. SERVICE#1 Config Server

SERVICE#2
SERVICE#3
Config Repository
Config Client
Config Client
Config Client

40. SERVICE#1 Config Server

Config Repository
Config Client
└── resources
├── application.yml # Spring Boot
└── bootstrap.yml # Spring Cloud
> service#1.jar
spring:
application.name: application
cloud.config.uri: https://config.arawn.io

41. Service discovery and configuration management with Apache Zookeeper.
Service discovery and configuration management with Hashicorp Consul.
Centralized external configuration management backed by a git repository. The
configuration resources map directly to Spring `Environment` but could be used
by non-Spring applications if desired.

42. Consul Server
(Cluster)
Consul Server
(Cluster)
SERVICE#1 Consul Server
(Cluster)

SERVICE#2
SERVICE#3
Git Repository
Consul Client
Consul Client
Consul Template
Jenkins
application.yml
https://www.consul.io
DNS
(load
balancer)

43. https://github.com/hashicorp/consul-template
Consul Server
(Cluster)
Consul Server
(Cluster)
SERVICE#1 Consul Server
(Cluster)

SERVICE#2
SERVICE#3
Git Repository
Consul Client
Consul Client
Consul Template
Jenkins
application.yml
DNS
(load
balancer)

44. datasource:
username: '{cipher}65794a6492kfc627782d59534d4845355167'
password: '{cipher}6575f2d938928525976712e6d7a679616641'
AWS
Key Management Service
AWS LAMBDA
Consul Server
(Cluster)
SERVICE#1

Git Repository
Consul Client Jenkins
application.yml
DNS
(load
balancer)

45. ORDER
SYSTEMUSER SERVICE
API GW
PRODUCT
SYSTEM
SCM
SYSTEM
EXTERNAL
SYSTEMS
MDM
SYSTEMBACK-OFFICE
SCM
SYSTEM

46. ORDER
SYSTEMUSER SERVICE
API GW
PRODUCT
SYSTEM
SCM
SYSTEM
EXTERNAL
SYSTEMS
MDM
SYSTEMBACK-OFFICE
SCM
SYSTEM

48. ✔ (strangler patterns)
✔ (strangler application)
✔ Refactoring a Monolith into Microservices
✔ API
✔ Pattern: API Gateway / Backend for Front-End
✔ Netflix Zuul : Importance of Reverse Proxy in Microservices Architecture
✔ Cloud Native Java
✔ The Twelve-Factor app (12 )