Build REST API with Golang

This talk in GDG DevFest Cordoba 2017

Transcript

1. Build REST API with Golang Esteban Dorado GDG DevFest Cordoba
2. Esteban Dorado @Mr_Esti
4. Pet servers Cattle servers
6. REST API
7. What is REST? • What does it stand for? Representational State Transfer • What is it? A style of software architecture for distributed systems • Who/Where/When? Came about in 2000 doctoral dissertation of Roy Fielding
8. REST Protocol Describes six (6) constraints: 1. Uniform Interface 2. Cacheable 3. Client-Server 4. Stateless 5. Code on Demand 6. Layered System
9. What is RESTful API? A RESTful API is an application program interface (API) that uses HTTP requests to GET, PUT, POST and DELETE data. A RESTful API -- also referred to as a RESTful web service -- is based on REST technology
10. PROs of RESTful API? REST technology is generally preferred to the more robust Simple Object Access Protocol (SOAP) technology because REST leverages less bandwidth, making it more suitable for internet usage.
11. REST - Core Where: URL based Resources: Data, files, methods... How: HTTP What: Up to you
12. Example URIs • GET http://www.example.com/v1/hr/employees/123818237 • POST http://www.example.com/v1/hr/employees • DELETE http://www.example.com/v1/hr/employees/145657723 • PUT http://www.example.com/v1/hr/employees/345875384
13. HTTP methods HTTP Verb CRUD HTTP Codes POST Create 201 (Created), 404 (Not Found), 409 (Conflict) GET Read 200 (OK), 404 (Not Found) PUT Update/Replace 405 (Method Not Allowed), 200 (OK), 204 (No Content), 404 (Not Found) PATCH Update/Modify 405 (Method Not Allowed), 200 (OK), 204 (No Content), 404 (Not Found) DELETE Delete 405 (Method Not Allowed), 200 (OK), 404 (Not Found)
14. Resources in REST? • Resources can be served in different representations: ◦ XML, JSON, HTML, etc. • Content negotiation methods • Headers: ◦ Accept or Content-Type • Query parameters ◦ GET /v1/users/10543?format=json • Uri extension ◦ GET /v1/users/10543.xml
15. Alternatives of REST API http://graphql.org https://grpc.io
17. REST API ¿ ?
19. EXPLORE
20. SIMPLE API https://goreportcard.com/report/github.com/mresti/guidetoprodu ction_api https://github.com/mresti/rest-api-golang/tree/simple_api
21. api.go var ( counter int port = 9000 ) func count(w http.ResponseWriter, r *http.Request) { if r.Method != "GET" { w.WriteHeader(http.StatusMethodNotAllowed) return } counter++ w.Header().Set("Content-Type", "application/json") w.WriteHeader(http.StatusAccepted) w.Write([]byte("{'Message': 'Hello DevFest Granada 2017'}")) }
22. api.go func stats(w http.ResponseWriter, r *http.Request) { if r.Method != "GET" { w.WriteHeader(http.StatusMethodNotAllowed) return } w.Header().Set("Content-Type", "application/json") w.WriteHeader(http.StatusOK) w.Write([]byte(fmt.Sprintf("{'Visits': %d}", counter))) }
23. api.go func main() { http.HandleFunc("/", count) http.HandleFunc("/stats", stats) log.Println("Listening at port ", port) log.Panic( http.ListenAndServe(fmt.Sprintf(":%d", port), nil)) }
27. api.go func main() { http.HandleFunc("/favicon.ico", func(_ http.ResponseWriter, _ *http.Request) {}) http.HandleFunc("/", count) http.HandleFunc("/stats", stats) log.Println("Listening at port ", port) log.Panic( http.ListenAndServe(fmt.Sprintf(":%d", port), nil)) } Add line
28. Let’s build your REST API as a PRO
30. PRO API https://goreportcard.com/report/github.com/mresti/guidetoprodu ction_api https://github.com/mresti/rest-api-golang/tree/professional _api
32. Pipeline: API in golang Build Integration Code Goreports
33. API: .travis.yml sudo: false language: go go: - 1.8.x - 1.9.x - pip matrix: allow_failures: - go: pip fast_finish: true Script: - make # Run format code, run tests and build code - make integrationtest # Run integration tests
34. Capture screen shot on ChromeOS device, and place here. Be sure to hide the bottom task bar that includes your image, open apps, etc. Ideal image size should be 1626x1080. When using those sizes, image position is {x: 147px, y: 63px} Add a CURVED SHADOW to the screen shot https://goreportcard.com/report/github.com/mresti/restful_a pi_golang
35. API: dockerfile FROM golang:1.9.2 ENV PATH /api:$PATH ARG API_PORT ENV PORT $API_PORT WORKDIR /api # Copy binary demo ADD ./api-linux-amd64 /api/demo # Modified files for titan RUN chmod 555 /api/demo # Expose ports EXPOSE $PORT # Run Titan CMD demo -port $PORT
36. API: docker-compose.yml version: "2.1" services: api: build: context: . args: API_PORT: "8081" ports: - "8081:8081"
37. ¿Will we build our gRPC API?
38. Learn API gRPC https://goreportcard.com/report/github.com/mresti/guidetoprodu ction_api https://codelabs.developers.google.com/codelabs/cloud-grpc/ index.html#0
39. Research & Development
40. Beers with friends...
41. Q&A
42. <thank-you> @Mr_Esti