Hexagonal architecture for dummies (and spring developer) @youen-chene
@saagie_io
Why hexagonal architecture?
@youen-chene
@saagie_io
Hexagonal/DDD Speaker (Jérome)
DDD & Hexagonal will save the world. 40mn to 1h57 before showing some code. No framework. Manual Bean & IoC instanciation.
@youen-chene
@saagie_io
Java/Kotlin Developer (Pierre)
No framework? it’s not real world stuff. What’s the value versus a layer architecture? Looks complicated.
@youen-chene
@saagie_io
“Parce que quand on est grand on arrête de mettre des couches” Cédric Champeau LCC#154
@youen-chene
@saagie_io
@youen_chene CTO @saagie_io Activiste : @normandyjug @codeursenseine @devoxx4kidsfr @n_w_x
Data Fabric
Data Governance
GDPR
Container Management Spark
Datanodes
Python
Keras Spring Boot
CPU
GPU
App/Dataviz
HTML, JS, CSS
Browser Server Controller
Controller
Service
DAO
Service
DAO
Service
DAO
DAO
HTML, JS, CSS
Browser Server Controller
Controller
Service
DAO = Business Rule
Service
DAO
Service
DAO
DAO
HTML, JS, CSS
Browser Server Controller
Controller
Service
DAO = Business Rule
Service
DAO
Service
DAO
DAO
HTML, JS, CSS
Browser Server Controller
Controller
Service
DAO = Piece of Business Rule
Service
DAO
Service
DAO
DAO
HTML, JS, CSS
Browser Server Controller
Controller
Service
DAO = Piece of Business Rule
Service
DAO
Service
DAO
DAO
if ($job->getCategory() == "dataviz" || $job->getCapsuleCode() == CapsuleInstance::JUPITER_CODE) { $notebookConfig = $this->managerConfig->getCapsules()->getNotebook(); return $notebookConfig->getMesostag(); } else if ($job!=null && $job->getCapsuleCode() == CapsuleInstance::SQOOP_CODE) { return "hdfs-master"; } else { return "hdfs"; }
Tackling Complexity in the Heart of Software Eric Evans 2003
@youen-chene
@saagie_io
Sexy Allistair Schema
@youen-chene
@saagie_io
Sister’ Architecture
@youen-chene
@saagie_io
Simple Hexagonal Architecture with Spring Boot
@youen-chene
@saagie_io
Let’s start by the domain
Domain
@youen-chene
@saagie_io
Let’s start by the domain
Domain
Rule 1 : no framework or lib dependency!!!!!!! @youen-chene
@saagie_io
Let’s start by the domain
Domain
Rule 2 : external call the inside @youen-chene
@saagie_io
One simple Rule
Domain
No Infra Code in the domain @youen-chene
@saagie_io
Back the domain
Domain
@youen-chene
@saagie_io
@youen-chene
@saagie_io
@youen-chene
@saagie_io
Let’s start by the domain
@youen-chene
@saagie_io
Hexagonal I/O
@youen-chene
@saagie_io
Accessing the Domain : (1) Primary Port
Classes, Functions, Methods, Service External Infrastructure call the inside
Domain Domain
(Ex: API Controller, Batch)
@youen-chene
@saagie_io
Accessing the Domain : (1) Primary Port
Classes, Functions, Methods, Service External Infrastructure call the inside
Domain Domain
(Ex: API Controller, Batch)
@youen-chene
@saagie_io
Accessing the Infrastructure Code : (2) Secondary Port
Interface
Domain Domain
Interface Implementation
Accessing/Pushing Data
@youen-chene
DB, Kafka, Rabbit, External API
@saagie_io
Accessing the Infrastructure Code : (2) Secondary Port
Interface
Domain Domain
Interface Implementation
Accessing/Pushing Data
@youen-chene
DB, Kafka, Rabbit, External API
@saagie_io
Co
nt r Ad AP olle r I ap te r
go on M DB er t ap Ad
Bo Spr ot ing Ap p
Infrastructure Code : With Adapters
Ba
tc
h
Ex ter AP nal A I d ap ter
h tc r Ba pte a Ad
Domain Domain Domain
@youen-chene
@saagie_io
Ports
Primary Port Driving Port Input Port
@youen-chene
Secondary Port Domain Domain Domain
Driven Port Output Port
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C o AP Ad ntro I ap lle te r r
Dirty technical shit
go on M DB er t ap Ad
Bo Spr ot ing Ap p
Infrastructure Code : With Adapters
Domain Domain Domain
Ba
tc
h
Ex ter AP nal A I d ap ter
h tc r Ba pte a Ad
Clean rule
@youen-chene
@saagie_io
Infrastructure Code : @Repository Spring Secondary Adapter MongoDB Adapter go on M B er D t ap
Ad
Domain Domain
Port (Interface)
@youen-chene
@saagie_io
Infrastructure Code : @Repository Spring Secondary Adapter MongoDB Adapter
Repository Spring bean Implements Port Kmongo as DAO
Implements method with domain, DAO and DTOs. @youen-chene
@saagie_io
Infrastructure Code : Data Transfer Object (DTO)
Mongo dependency
Boring Mapping
Boring Mapping
@youen-chene
@saagie_io
Back to Spring Boot
Domain Object
Bean @Repository class FeatureRecordsMongoRepository
DTO
KMongo @youen-chene
@saagie_io
Infrastructure Code : Spring Application Primary Adapter
Co AP Ad ntro I ap lle te r r
Bo Spr ot ing Ap p
Spring Boot App
Domain Domain @youen-chene
@saagie_io
Back to Spring Boot @SpringBootApplication class FeaturebrawlApplication
Domain Object
Instanciate
Bean @Repository class FeatureRecordsMongoRepository
DTO
KMongo @youen-chene
@saagie_io
Infrastructure Code : Spring Application Primary Adapter
Spring Boot App
Co AP Ad ntro I ap lle te r r
Bo Spr ot ing Ap p
Spring API Controller Adapter
Domain Domain @youen-chene
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Infrastructure Code : Spring Application Primary Adapter Spring API Controller Adapter
RestController Spring bean Inject FeatureManagement Port
Use FeatureManagement Port
@youen-chene
@saagie_io
API Calls DTO
@SpringBootApplication class FeaturebrawlApplication
Instanciate
@RestController class FeatureSpringRestController
Bean
Domain Object
Instanciate
Bean @Repository class FeatureRecordsMongoRepository
DTO
KMongo @youen-chene
@saagie_io
API Calls DTO
@SpringBootApplication class FeaturebrawlApplication
Instanciate
@RestController class FeatureSpringRestController
Bean
Domain
Domain Object
Instanciate
Bean @Repository class FeatureRecordsMongoRepository
DTO
KMongo @youen-chene
@saagie_io
@youen-chene
@saagie_io
One simple Rule
Domain
No Infra Code in the domain @youen-chene
@saagie_io
Infrastructure Code : Hack all Together
@youen-chene
@saagie_io
Infrastructure Code : Hack all Together
Service Spring bean to expose the primary port as a spring bean bean
@youen-chene
@saagie_io
Infrastructure Code : Hack all Together
So it can be injected by spring here (Rest controller primary adapter)
Service Spring bean to expose the primary port as a spring bean bean
@youen-chene
@saagie_io
Infrastructure Code : Hack all Together
Inject Repository Secondary Adapter.
@youen-chene
@saagie_io
Infrastructure Code : Hack all Together
Inject Repository Secondary Adapter. So it can use the @repository spring bean (repository primary adapter)
@youen-chene
@saagie_io
API Calls DTO
@SpringBootApplication class FeaturebrawlApplication
Instanciate
@RestController class FeatureSpringRestController
Bean
Domain Object
Instanciate
Bean @Service class FeatureManagementSpringHandler Domain Domain Object
Instanciate
Bean @Repository class FeatureRecordsMongoRepository
DTO
KMongo @youen-chene
@saagie_io
It’s a little bit crappy, no?
@youen-chene
@saagie_io
Spring Boot on it’s nominal use case Hexagonal Architecture respected Domain still clean.
@youen-chene
@saagie_io
C o AP Ad ntro I ap lle te r r
Dirty technical shit
go on M DB er t ap Ad
Bo Spr ot ing Ap p
Infrastructure Code : With Adapters
Domain Domain Domain
Ba
tc
h
Ex ter AP nal A I d ap ter
h tc r Ba pte a Ad
Clean rule
@youen-chene
@saagie_io
https://github.com/youenchene/featurebrawl
@youen-chene
@saagie_io
Pros
Cons
Clean Domain/Business Rules
DTOs make it a little heavy
Fast unit test on the domain
Developer need to be trained
Better code scalability
No starter like jHipster
@youen-chene
@saagie_io
One simple Rule
Domain
No Infra Code in the domain @youen-chene
@saagie_io
C o AP Ad ntro I ap lle te r r
Dirty technical shit
go on M DB er t ap Ad
Bo Spr ot ing Ap p
Questions?
Domain Domain Domain
Ba
tc
h
Ex ter AP nal A I d ap ter
h tc r Ba pte a Ad
Clean rule
@youen-chene
@saagie_io
