RESTful APIs in ASP.NET Core

APIs are everywhere, in fact; for most things today one could say “there’s an API for that”. Microsoft’s ASP.NET Core is a brand new web framework, completely open sourced and cross platform; for building scalable- & cloud ready web applications.

In this interactive talk we go on a journey to discover some of the features ASP.NET Core offers for building practical RESTful APIs like Logging, Middleware, Routing, Configuration, Dependency Injection, Hosting and Servers. All hands on deck, it’s going to get messy!

Transcript

1. RESTful APIs with ASP.NET Core
2. Hello! Fanie Reynders Husband & Father, Engineer, MVP, Cloud Technology Evangelist @FanieReynders http://reynders.co
3. http://reynders.co
4. http://sdncast.nl
5. https://meetup.com/dutchdotnet
6. API Application Programming Interface
7. “ An Application Programming Interface is a protocol intended to be used as an interface by software components to communicate with each other.
8. REST Representational State Transfer
9. /this/does/not/mean/rest { “neither” : “does this” }
10. /getAllProfiles /getProfile?id=2 /createProfile /deleteProfile?id=4 /updateProfile?name=eddy
11. /getAllProfiles /getProfile?id=2 /getProfileWithFriends?id=2 /searchProfileByName?name=frank /createProfile /deleteProfile?id=4 /updateProfile?name=eddy
12. /getAllProfiles /getAllProfilesJson /getAllProfilesCsv /getProfile?id=2 /getProfile?id=2&json=1 /getProfileWithFriends?id=2 /getProfileWithFriends?id=2&json=1 /searchProfileByName?name=frank /searchProfileByName?name=frank&json=1 /createProfile /deleteProfile?id=4 /updateProfile?name=eddy
13. REST vs RPC Resources Server Functions
14. “ Representational State Transfer is a style of architecture based on a set of principles that describe how networked resources are defined and addressed
16. ASP.NET Core http://get.asp.net
17. ASP.NET Core OSS X-Plat Modular On prem or cloud .NET Core & 4.x Fast Your fav editor
18. Hosting Middleware DI Configuration Logging Application Frameworks ASP.NET Core
19. .NET Framework 4.6 Full .NET Framework .NET Core 1.x Modular libraries & runtime Optimized for server & cloud ASP.NET 4.6 System.Web ASP.NET Core 1.x Web Forms MVC Web API MVC Web Pages
20. Thou shalt be RESTful
21. Client-Server ✉
22. public class Program { public static void Main(string[] args) { var host = new WebHostBuilder() .UseKestrel() .Configure(app => app.Run(async context => await context.Response.WriteAsync("Hello World!"))) .Build(); host.Run(); } }
23. Layered System ✉
24. Request Response Kestrel Middleware 1 Middleware 2 Middleware 3 Middleware 1 Middleware 2 Middleware 3 Middleware 1 Middleware 2 ASP.NET Core Middleware
25. Uniform Interface Media types Methods Resource identifier syntax
26. /getAllProfiles /getAllProfilesJson /getAllProfilesCsv /getProfile?id=2 /getProfile?id=2&json=1 /getProfileWithFriends?id=2 /getProfileWithFriends?id=2&json=1 /searchProfileByName?name=frank /searchProfileByName?name=frank&json=1 /createProfile /deleteProfile?id=4 /updateProfile?name=eddy
27. GET • Accept: • application/json • text/csv • /profiles • /profiles?{name} • /profiles/{id} • /profiles/{id}/friends POST • Accept: • application/json • /profiles • { … } PUT • Accept: • application/json • /profiles/{id} • { … } DELETE • Accept: • application/json • /profiles/{id}
28. Stateless ✉
29. HATEOAS Hypermedia as the Engine of Application State
30. “ HATEOAS is a constraint of the REST stateless application which allows a REST client to have no prior knowledge about how to interact with the server beyond a generic understanding of hypermedia provided by the API.
31. GET /people/2 HTTP/1.1 Host: api.awesome.io Accept: application/json { "_links": [ { "rel": "self", "href": "http://api.awesome.io/people/2" }, { "rel": "update-person", "href": "http://api.awesome.io/people/2", "method": "PUT" }, { "rel": "remove-person", "href": "http://api.awesome.io/people/2", "method": "DELETE" } ], "name": "Joe", "surname": "Soap" }
32. Cacheable ✉
33. GET /languages HTTP/1.1 Host: api.awesome.io Accept: application/json HTTP/1.1 200 OK Content-Type: application/json Cache-Control: max-age=3600 Content-Length: 88 Etag: "6d82cbb050ddc7fa9cbb659014546e59" { "languageCodes": [ {"da":"Danish"}, {"no":"Norwegian"}, {"en":"English"} ] }
34. GET /languages HTTP/1.1 Host: api.awesome.io Accept: application/json If-None-Match: "6d82cbb050ddc7fa9cbb659014546e59" HTTP/1.1 304 Not Modified Etag: "6d82cbb050ddc7fa9cbb659014546e59"
35. Code On Demand* ✉
38. Don’t just call your API “RESTful”
39. Client- Server Layered System Uniform Interface Stateless Cacheable Code On Demand
40. https://www.visualstudio.com https://code.visualstudio.com https://get.asp.net https://docs.microsoft.com/aspnet/core
41. Thanks! Any questions? You can find me at @FanieReynders & fanie@reynders.co