Rapid API Development in Go Josh Michielsen 

About Me → Snr Software Engineer, Platform Engineering @ Condé Nast (@condenasteng) → K8s, AWS, Go → Cyclist → Photographer → Dog Lover! @jmickey_ jmichielsen jmickey mickey.dev [email protected] 

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Third Party Libraries A look at some popular 3rd party libraries that make API development easier. Conclusion What Makes Go Unique? Briefly explore what makes Go different from other languages. Language Introduction A quick dive into the basics of the Go Programming Language. Web & APIs in Go Jumping right into some code, I will demo how to utilise the Go standard library to create a simple web server and API. 01 AGENDA 02 03 05 04 

What Makes Go Unique 01 

Features → Clear and concise syntax → Simple concurrency model → Strong built-in tooling → Compiled into a single statically linked binary → Robust standard library → Faster than Python 

Projects That Use Go → Kubernetes → Hashicorp Toolkit → Prometheus → Docker 

Language Introduction 02 

package main import "fmt" func main() { friend := "DDD East Anglia" fmt.Printf("Hello, %s", friend) } Package declaration. Main pkg produces a binary. Import statements. Function declaration. Main pkg must have function main. Variable. Will infer the type based on the right side of :=. Print a string using the ‘fmt’ package. 

Some Examples → Lets jump into VS Code and “go” though some examples. Links to these code samples and other are provided at the end of the slide deck. 

Concurrency → “Goroutines” are lightweight threads that provide a simple concurrency primitive. → “Channels” allow for communication between Goroutines. → Goroutines are launched using the go keyword. 

package main import ( "fmt" "time" ) func say(s string) { for i := 0; i < 5; i++ { time.Sleep(100 * time.Millisecond) fmt.Println(s) } } func main() { go say("world") say("hello") } world hello hello world world hello hello world world hello Via ‘A Tour of Go’ - https://tour.golang.org/concurrency/1 Goroutines 

package main import "fmt" func main() { messages := make(chan string) go func() { messages <- "ping" } msg := <-messages fmt.Println(msg) } Channels Via ‘Go by Example’ - https://gobyexample.com/channels Make a channel. Channels are typed. The <- operator sends the string to the channel. Receive from the channel and assign to a variable. 

Compilation → Go compiles code into a single binary. → Binaries can be statically linked. → Cross-platform compilation is built-in. → Supports various architectures. CGO_ENABLED=0 go build GOOS=windows go build GOARCH=arm go build http://bit.ly/go-build-values 

Web & APIs 03 

Examples → Simple Web Server → JSON Response → Middleware → Dynamic Routing → Gorilla Mux 3rd Party Library Link to the repo with the examples is provided at on the final slide of the presentation. 

Third Party Libraries 05 

Gorilla Toolkit → Toolkit of libraries that simplify web application and API development. https://www.gorillatoolkit.org/ HttpRouter → Performant & light HTTP router with QoL improvements over net/http. https://github.com/julienschmidt/httprouter Go Kit Micro → Another popular microservices “runtime”. https://github.com/micro/micro → Popular microservices framework. https://github.com/go-kit/kit 

Conclusion 06 

→ Go is a fast, powerful language that provides a simple and concise syntax. → Web development and API development is possible with nothing but the standard library. → Cross-platform compilation allows you to run your applications almost anywhere. → Most 3rd party libraries simply add a nicer UX over the standard HTTP implementation. 

VSCode Go Plugin → Great Visual Studio Code Go plugin. https://marketplace.visualstudio.com/items?itemNa me=ms-vscode.Go Go by Example → Fantastic Go language tutorial with annotated code samples. https://gobyexample.com/ Go in Action How to Write Go Code → Getting started guide by the language developers/designers. https://golang.org/doc/code.html → Highly coveted Go book. https://www.manning.com/books/go-in-action 

http://bit.ly/go-samples Thanks for Listening! @jmickey_ jmichielsen jmickey mickey.dev [email protected]