ondrejsika / golang-training

Ondrej Sika (sika.io) | [e-mail]

Golang Training

Course

Install Go

• https://go.dev/doc/install

Mac

brew install golang

Setup Go Project

mkdir hello-world

cd hello-world

VS Code Setup

Install Go extension

• https://marketplace.visualstudio.com/items?itemName=golang.Go

Optional extensions

• https://marketplace.visualstudio.com/items?itemName=EditorConfig.EditorConfig

For monorepo support add to settings.json

"gopls": {
    "experimentalWorkspaceModule": true,
}

editorconfig

Create .editorconfig file

root = true
[*]
indent_style = space
indent_size = 2
charset = utf-8
trim_trailing_whitespace = true
insert_final_newline = true
end_of_line = lf
max_line_length = off
[Makefile]
indent_style = tab
[*.go]
indent_style = tab

Create .editorconfig file using slu

slu ft ec --go

gitignore

Create simple .gitignore where hello-world is the output binary, which is the package name.

# Global
.DS_Store

# Editor
.vscode

# Go
/hello-world
/hello-world.exe
/dist

or using slu ft gitignore --go --go-package hello-world

go mod init

go mod init hello-world

or

go mod init github.com/ondrejsika/hello-world

main.go

Create main.go file

package main

import "fmt"

func main() {
  fmt.Println("Hello World")
}

go run

go run main.go

or

go run .

go build

Build

go build

and run

./hello-world

or on windows

./hello-world.exe

Build to custom name

go build -o dist/hello

You can build single file using go build example-server.go and output will be example-server

Cross Platform Build

GOOS=linux GOARCH=amd64 go build -o dist/hello-linux-amd64
GOOS=darwin GOARCH=arm64 go build -o dist/hello-darwin-arm64
GOOS=windows GOARCH=amd64 go build -o dist/hello-windows-amd64.exe

A Tour of Go

https://go.dev/tour/list

Offline Tour

Install

go install golang.org/x/website/tour@latest

Run

~/go/bin/tour

Go By Example

https://gobyexample.com/

Go Install

go install github.com/sikalabs/hello-world-server@latest

CLI with Cobra

• https://github.com/spf13/cobra

Examples

• Simple Example - https://github.com/ondrejsika/golang-examples/tree/master/cobra_example_simple
• Quick Start Example - https://github.com/ondrejsika/golang-examples/tree/master/cobra_example

Configuration with Viper

• Viper with only environment variables - https://github.com/ondrejsika/golang-examples/tree/master/viper_env_only
• Simple Viper example - https://github.com/ondrejsika/golang-examples/tree/master/viper_example
• Cobra and Viper - https://github.com/ondrejsika/golang-examples/tree/master/viper_and_cobra_example_advanced

Build Optiopns

For smaller binaries

go build --ldflags "-s -w"

Trim paths

go build --trimpath

Final production build

go build --trimpath --ldflags "-s -w"

Goreleaser

• https://goreleaser.com/
• https://github.com/goreleaser/goreleaser

Install Goreleaser

• https://goreleaser.com/install/

Install Goreleaser using Go

go install github.com/goreleaser/goreleaser@latest

Install Goreleaser on Mac

brew install goreleaser

Create .goreleaser.yaml

gorleaser init

or here is my example of .goreleaser.yaml

project_name: hello-world

before:
  hooks:
    - rm -rf dist
    - go mod tidy
    - git push
    - git push --tags

builds:
  - env:
      - CGO_ENABLED=0
    goos:
      - linux
      - windows
      - darwin
    flags:
      - -trimpath
    ldflags:
      - -s
      - -w
      - -X hello-world/version.Version=v{{.Version}}

snapshot:
  name_template: "{{ incminor .Version }}-dev"

archives:
  - format: tar.gz
    name_template: "{{ .ProjectName }}_v{{ .Version }}_{{ .Os }}_{{ .Arch }}"
    format_overrides:
      - goos: windows
        format: zip

checksum:
  name_template: "{{ .ProjectName }}_checksums.txt"
  algorithm: sha256

For custom Gitlab, you have to add gitlab_urls section

gitlab_urls:
  api: https://gitlab.sikalabs.com/api/v4/
  download: https://gitlab.sikalabs.com

Goreleaser Build

Snapshot

goreleaser build --snapshot --rm-dist

Release build

git tag v0.1.0

goreleaser build --rm-dist

Goreleaser Release

goreleaser release --rm-dist

or just

goreleaser

Download the release from Github using slu on Mac

slu install-any-bin \
  --url https://github.com/ondrejsika/example-for-golang-training/releases/download/v0.1.0/hello-world_v0.1.0_darwin_arm64.tar.gz \
  --name hello-world \
  --bin-dir .

or on Linux

slu install-any-bin \
  --url https://github.com/ondrejsika/example-for-golang-training/releases/download/v0.1.0/hello-world_v0.1.0_linux_amd64.tar.gz \
  --name hello-world \
  --bin-dir .

Logging

• https://github.com/rs/zerolog
• https://github.com/sirupsen/logrus

Logging with Zerolog

• https://github.com/ondrejsika/golang-examples/tree/master/zerolog_example

Writing Docs

• https://go.dev/blog/godoc

Example

• https://gitlab.sikalabs.com/go/hello-from-gitlab-demo
• https://pkg.go.dev/gitlab.sikalabs.com/go/hello-from-gitlab-demo

godoc server

Install

go install golang.org/x/tools/cmd/godoc@latest

Run

~/go/bin/godoc -http=:8080

Private Modules

Set GOPRIVATE env variable

export GOPRIVATE=gitlab.sikalabs.com,gitlab.sikademo.com

export GOPRIVATE='*'

Use ssh keys instead of https on gitlab.sikalabs.com

git config --global url."[e-mail]:".insteadOf "https://gitlab.sikalabs.com/"

or use .netrc file

machine gitlab.sikalabs.com
login token
password glpat-rKKSwt8izeXUGGWu7PEV

Example

go get -u gitlab.sikalabs.com/go/hello-from-gitlab-private

// main.go

package main

import "gitlab.sikalabs.com/go/hello-from-gitlab-private"

func main() {
	hello.HelloFromGitlab()
}

Thank you! & Questions?

That's it. Do you have any questions? Let's go for a beer!

Ondrej Sika

• email: [e-mail]
• web: https://sika.io
• twitter: @ondrejsika
• linkedin: /in/ondrejsika/
• Newsletter, Slack, Facebook & Linkedin Groups: https://join.sika.io

Do you like the course? Write me recommendation on Twitter (with handle @ondrejsika) and LinkedIn (add me /in/ondrejsika and I'll send you request for recommendation). Thanks.

Wanna to go for a beer or do some work together? Just book me :)

Resources

• Example Project - https://github.com/ondrejsika/example-for-golang-training
• Golang Examples - https://github.com/ondrejsika/golang-examples
• My Golang Projects
  • slu - CLI utils - https://github.com/ondrejsika/slu
  • gobble - Ansible alternative in Go - https://github.com/ondrejsika/gobble
  • tergum - Backup tool - https://github.com/ondrejsika/slu

Training Sessions

2023-05-29

• https://github.com/golang-training-examples/example1
• https://gitlab.sikalabs.com/go/hello-world