HEXAGONAL ARCHITECTURE Victor "Frodo" Martinez June, 2022 Photo by Marcel Strauß

● INTRODUCTION AND THEORETICAL BACKGROUND (20min) ● SHOW ME THE CODE (20min) ● QUESTIONS (5min) TOTAL = 45min AGENDA

! DISCLAIMER

WHY ?

ONCE UPON A TIME… Photo by Brian McGowan

THE NEW SUPER-SECRET MEGA BLAST DISRUPTIVE INNOVATIVE DATA-DRIVEN PROJECT

THE NEW SUPER-SECRET MEGA BLAST DISRUPTIVE INNOVATIVE DATA-DRIVEN PROJECT

LOGIC THE NEW SUPER-SECRET MEGA BLAST DISRUPTIVE INNOVATIVE DATA-DRIVEN PROJECT

LOGIC THE NEW SUPER-SECRET MEGA BLAST DISRUPTIVE INNOVATIVE DATA-DRIVEN PROJECT

LOGIC FLASK CLI THE NEW SUPER-SECRET MEGA BLAST DISRUPTIVE INNOVATIVE DATA-DRIVEN PROJECT

LOGIC FLASK CLI THE NEW SUPER-SECRET MEGA BLAST DISRUPTIVE INNOVATIVE DATA-DRIVEN PROJECT

LOGIC FLASK CLI THE NEW SUPER-SECRET MEGA BLAST DISRUPTIVE INNOVATIVE DATA-DRIVEN PROJECT

LOGIC FLASK CLI PROBLEMS

LOGIC FLASK CLI PROBLEMS TECHNOLOGY-DRIVEN LACK OF DOMAIN COUPLED TO TECHNOLOGY HARD TO CHANGE

MEDICAL ANNECDOTE

YOUR PROJECT IS NOT THE UNDERLYING TECHNOLOGY.

TECHNICAL COMPLEXITY VS BUSINESS COMPLEXITY

TECHNICAL COMPLEXITY DATABASE PERSISTENCE QUEUE PUBLISHING FILE STORAGE CACHE API

BUSINESS COMPLEXITY ESTIMATED DELIVERY TIME GENERATE CONTRACT ORDER A PRODUCT CALC TAXES

HEXAGONAL ARCHITECTURE

HEXAGONAL ARCHITECTURE Allow an application to equally be driven by users, programs, automated test or batch scripts, and to be developed and tested in isolation from its eventual run-time devices and databases. Alistair Cockburn 2005, Ports and Adapters

HEXAGONAL ARCHITECTURE Allow an application to equally be driven by users, programs, automated test or batch scripts, and to be developed and tested in isolation from its eventual run-time devices and databases. Alistair Cockburn 2005, Ports and Adapters Hexagonal Architecture OR Hexagonal Design?

"Atividades relacionadas a arquitetura de software são sempre de design. Entretanto, nem todas atividade de design são sobre arquitetura. O objetivo primário da arquitetura de software é garantir que os atributos de qualidade, restrições de alto nível e os objetivos do negócio, sejam atendidos pelo sistema. Qualquer decisão de design que não tenha relação com este objetivo não é arquitetural. Todas as decisões de design para um componente que não sejam “visíveis” fora dele, geralmente, também não são."- Elemar Jr. https://eximia.co/quais-sao-as-diferencas-entre-arquitetura-e-design-de-software/

LET'S DIVE INTO PORTS & ADAPTERS Photo by Brina Blum

LET'S DIVE INTO PORTS & ADAPTERS Photo by Brina Blum INTERFACES & IMPLEMENTATIONS

LET'S DIVE INTO PORTS & ADAPTERS Photo by Brina Blum PORT ADAPTER INTERFACES & IMPLEMENTATIONS

LET'S DIVE INTO PORTS & ADAPTERS

LET'S DIVE INTO PORTS & ADAPTERS INTERFACES & IMPLEMENTATIONS

LET'S DIVE INTO PORTS & ADAPTERS INTERFACES & IMPLEMENTATIONS SOLID

LET'S DIVE INTO PORTS & ADAPTERS INTERFACES & IMPLEMENTATIONS SOLID DEPENDENCY INVERSION PRINCIPLE

DEPENDENCY INVERSION PRINCIPLE "High level modules should not depend on low level modules; both should depend on abstractions. Abstractions should not depend on details. Details should depend upon abstractions."

DEPENDENCY INVERSION PRINCIPLE "High level modules should not depend on low level modules; both should depend on abstractions. Abstractions should not depend on details. Details should depend upon abstractions." DEPEND ON ABSTRACTIONS, NOT DETAILS.

DEPENDENCY INVERSION PRINCIPLE PORT: DATABASE

DEPENDENCY INVERSION PRINCIPLE ADAPTER: DATABASE

DEPENDENCY INVERSION PRINCIPLE PORT: CONTROLLER

DEPENDENCY INVERSION PRINCIPLE ADAPTER: CONTROLLER

ANATOMY

DOMAIN PORT PORT PORT PORT PORT PORT ADAPTER ADAPTER ADAPTER ADAPTER ADAPTER ADAPTER API DATABASE MESSAGE BROKER AUTH UI NOTIFICATION ANATOMY

CREATE CONTRACT ANATOMY

CREATE CONTRACT DATA PORT ANATOMY

CREATE CONTRACT DATA PORT ADAPTER REST API ANATOMY

CREATE CONTRACT DATA PORT ADAPTER REST API DB PORT ANATOMY

CREATE CONTRACT DATA PORT ADAPTER REST API DB PORT ADAPTER POSTGRES DATABASE ANATOMY

CREATE CONTRACT DATA PORT ADAPTER REST API DB PORT ADAPTER POSTGRES DATABASE STORAGE PORT ANATOMY

CREATE CONTRACT DATA PORT ADAPTER REST API DB PORT ADAPTER POSTGRES DATABASE STORAGE PORT ADAPTER S3 STORAGE ANATOMY

ANATOMY

INPUT ANATOMY

INPUT PROCESSING ANATOMY

INPUT PROCESSING OUTPUT OUTPUT ANATOMY

ADAPTER ADAPTER ADAPTER ADAPTER ADAPTER ADAPTER INPUT ADAPTERS OUTPUT ADAPTERS

DOMAIN PORT PORT PORT PORT PORT PORT ADAPTER ADAPTER ADAPTER ADAPTER ADAPTER ADAPTER API DATABASE MESSAGE BROKER AUTH UI NOTIFICATION WHAT IF WE NEED TO CHANGE THE ADAPTER?

WHAT IF WE NEED TO CHANGE THE ADAPTER? DOMAIN PORT PORT PORT PORT PORT PORT A A A A A FLASK POSTGRES RABBITMQ … SNS A PUBSUB A SQS A REDIS A MONGODB A FIREBASE A A FALCON APPLE A HUG A A A A A … … … … …

IT'S ALL ABOUT S O L I D Figure: Pereira, Matheus. "Capitals of classical antiquity: Understand the difference between the 5 orders" ArchDaily, May 2018, www.archdaily.com/892595/capitals-of-classical-antiquity-understand-the-difference-between-the-5-orders. Accessed 1 June, 2022.

"TALK IS CHEAP. SHOW ME THE CODE." - LINUS TORVALDS https://github.com/victormartinez/ flask-hexagonal