The document discusses patterns and best practices for building microservices architectures using .NET Core and API gateways. It covers common microservices patterns like API gateways, cross-cutting concerns, communication, and service discovery. It also provides an overview of the Ocelot API gateway for .NET Core, including features like routing, authentication, and integration challenges. Lessons learned from building microservices applications in the past four years are also briefly discussed.

1. Enterprise
Microservices
(with api gateways, .net core and micro ORMs)
Krishnanand Sivaraj for BDotNet UG

2. Monolith Microservices

3. Common Patterns
● API gateway
● Cross cutting concerns
● Communication
● Service Discovery
● Reliability
● Data Management
● Observability
● Deployment

4. Patterns
● API gateway

6. Api Gateways

7. Ocelot
● Api Gateway for .net core
● Open-source
● Nuget

8. Ocelot Features
● Routing
● Request Aggregation
● Authentication
● Authorization
● Rate Limiting
● Caching
● Logging
● Tracing
● Service Discovery

9. Demo
● Watch me make a live api gateway on twitch.tv (in future)
● Showing ReRoutes
● Explaining upstream and downstream parameters
● Showing global configurations
● Explaining challenges with integrating swagger

10. Challenges with Ocelot and solution
● Swagger integration
● https://github.com/Burgyn/MMLib.SwaggerForOcelot

11. Patterns
● APIs
● Cross cutting concerns
● Communication
● Service Discovery
● Reliability
● Data Management
● Observability
● Deployment

12. Patterns
● Cross cutting concerns
○ Externalized configuration – creating configurations for environment
○ Logging – how we log errors with trace information
○ Health checks - Microsoft.AspNetCore.Diagnostics.HealthChecks ,
https://github.com/xabaril/beatpulse
○ Authentication – passing access tokens, bearer tokens

13. Patterns
● Cross cutting concerns

14. Patterns
● APIs
● Cross cutting concerns
● Communication
● Service Discovery
● Reliability
● Data Management
● Observability
● Deployment

15. Patterns
● Communication

16. Patterns
● APIs
● Cross cutting concerns
● Communication
● Service Discovery
● Reliability
● Data Management
● Observability
● Deployment

17. Patterns
● APIs
● Cross cutting concerns
● Communication
● Service Discovery
● Reliability
● Data Management
● Observability
● Deployment

18. Patterns
● Reliability
○ YouTube videos have a retry attempts for their apis (demo).
○ Is REST dying? gRPC

19. Patterns
● APIs
● Cross cutting concerns
● Communication
● Service Discovery
● Reliability
● Data Management
● Observability
● Deployment

20. Lessons learnt (from the past 4yrs)
● Not decomposing based on business model
● Not considering DevOps from the initial phase of development
● Keeping test automation at the last phase
● .net core vs .net standard
● Too many client libraries against bare-bone REST

21. Microservices Assessment Platform
● https://platform.microservices.io

22. MicroORM (Dapper)
● To be continued..

23. References
● Microservices.io
● .net’s eshoponcontainers
● https://www.c-sharpcorner.com/members/catcher-wong

24. Krishnanand Sivaraj
● Lead Software Engineer , Deloitte, Managed Services & Products (Thoughts are my own)
● Blog: https://devkrishnanandsivaraj.wordpress.com
● Twitch: https://www.twitch.tv/dreamproductshq
● Twitter: https://twitter.com/krishnanandsiva
Thank You