Why Go?

Go is becoming a popular language of choice for building apps and APIs. This talk will cover some of the top reasons why you might want consider Go:
- Simplicity
- Concurrency
- Performance

We will cover how Go differs from other languages and some of “the Go way” of doing things. Lastly we will discuss how we’ve used Go in production to build APIs in a micro service, gRPC world!

Transcript

1. Why Prairie Dev Con, June 2019 @markstgodard ?
3. Agenda • What is Go? • Why use Go? • How we use Go at
4. A Brief History
5. { Background 1997 C / C++
6. { Background 2003 2014
7. { Background 2015 2017
8. { Background 2017 2019
9. { Background 2017 2019
10. What is Go?
11. What is Go? is a modern, general purpose programing language
12. What is Go? • Created by Google (2007) ◦ Rob Pike, Ken Thompson, Rob Griesemer • Open Source (2009) • Statically typed • Compiles to an executable ◦ GOOS=linux GOARCH=amd64 • Garbage collected • Syntactically similar to C
13. What is Go? • Simple • Predictable • Concurrency • Performance • Productive
14. Who is using Go? https://github.com/golang/go/wiki/GoUsers
15. Demo Hello World
16. What is Go? • Technically not OO • Functions and Structs • Interfaces • Concurrency model ◦ Goroutines, channels • Pointers • Pass by value • First class functions
17. Funcs & Structs
18. Functions
19. Functions
20. Structs
21. Pointer receiver
22. Methods
23. What is NOT in Go? • No inheritance • No constructors or destructors • No overloading functions • No operator overloading • No generics (yet) • No exceptions
24. Things I like about ❤
25. Interfaces
26. Go interfaces • Interfaces are implicit • Types do not have to explicitly “implement” • Duck typing • Compile time
27. Go interfaces
28. Go interfaces
29. Go interfaces
30. Go interfaces
31. Go interfaces
32. Go interfaces • More than just a convenience • Loosely coupled • Favour thinner interfaces ◦ Compose interfaces • Define interfaces where they are used ◦ Next example... • Unit testability
34. Go interfaces • Example define interface close to where used
35. Go interfaces • Example define interface close to where used
38. Concurrency
39. Go concurrency • Concurrency built into the language • Goroutines ◦ Function that can run concurrently with other funcs • Channels ◦ How goroutines can communicate and synchronize execution ◦ Can be buffered or unbuffered
40. Goroutines
41. Goroutines
42. Go concurrency
43. Go concurrency
44. Go concurrency
45. Go concurrency
46. Go concurrency
47. Go concurrency
48. go fmt ✨
49. Go fmt • go fmt • Part of the go toolchain • Automatic code formatting ◦ Integrates with most editors, IDEs • Simplifies reading, writing code • Uncontroversial ◦ No more debates
50. go test
51. Go test • go test ◦ Unit testing is built into the language • Part of the standard library testing package • Basic but there are frameworks that extend • For info on how Bold does unit testing: ◦ https://medium.com/boldly-going/unit-testing-in-go-wit h-ginkgo-part-1-ce6ff06eb17f
52. go vet
53. Go vet • go vet ◦ Static testing is built into the toolchain ◦ https://golang.org/cmd/vet/ • Linting • Unsafe or suspicious code • Great lint aggregators ◦ golangci-lint ◦ https://golangci.com/
54. Things that may initially feel strange about
55. Things that may seem weird at first... • No inheritance or objects ◦ Composition over inheritance ◦ Embedded types but not subclassing • Go is not really a OO, but ◦ Types, methods and interfaces ◦ Encapsulation
56. Things that may seem weird at first... • Order of variables and types ◦ variable < - > type
57. Things that may seem weird at first... • Packages ◦ Favours putting “like things” together in packages ◦ Organize around responsibility • Habits of splitting by layer ◦ models, services, controllers, ... • Does not allow cycles between packages
58. Things that may seem weird at first... • Naming ◦ Favours short names ◦ Packages, variables • The greater the distance between declaration and use, longer the name • Idiomatic Go-isms ◦ ok, err • What is in a name? (Andrew Gerrand)
59. Things that may seem weird at first... • Multiple returns ◦ Go supports multiple return types ◦ Almost always 2 or less ◦ 2nd being of type error • Returning early ◦ Within a func, returning when an error ◦ No dogmatic “single return” • Example...
60. Things that may seem weird at first...
61. Things that may seem weird at first... • Frameworks ◦ Go standard library ◦ http package for HTTP handlers • There are some useful frameworks and libs ◦ gorilla: http routing, dispatching ◦ squirrel: fluent SQL building • Recommend looking at stdlib first
62. +
63. How Bold uses Go • Historically mostly PHP • Started adopting Go ~2016/2017 • PHP / Laravel ◦ Unnecessary overhead for a simple API • Workloads ◦ Background / async jobs ◦ REST APIs ◦ gRPC services
64. How Bold uses Go • Microservices ◦ Decompose based on capability • Unit Tests ◦ ginkgo • Build ◦ Docker images • Deploy ◦ Kubernetes
65. Docker image
66. Docker image (local dev w/ hot reloading)
67. docker-compose (local dev w/ hot reloading)
68. How Bold uses Go api gateway API 1 API 2 API 3 API 4 API (n) https gRPC
69. Kubernetes Node 1 Node 2 Node 3 API api gateway API api gateway API API API API API API API API API API API API
70. In Summary
71. Summary • Go is a great general purpose language • Simple, easy to learn • Concurrency model • Unit testing • Looking for frameworks? ◦ Rails (ruby), Laravel (php) • Lots of great resources online to learn...
72. Resources • A Tour of Go ◦ https://tour.golang.org • Go by Example ◦ https://gobyexample.com • Go Playground ◦ https://play.golang.org • Boldly Going (our technical blog) ◦ https://medium.com/boldly-going
73. Questions? @markstgodard