gotoolbox

README

gotoolbox

A kitchen sink of Go tools that I've found useful. Uses only the standard library, no external dependencies.

contents

• super lightweight http server library
• exponential backoff retry
• working with JSON
• working with the file system
• working with slices
• working with CLIs

example usage

go get github.com/jritsema/gotoolbox

utilities

package main

import "github.com/jritsema/gotoolbox"

func main() {

	s := []string{"a", "b", "c"}
	if gotoolbox.SliceContainsLike(&s, "b") {
		fmt.Println("b exists")
	}

	err := gotoolbox.Retry(3, 1, func() error {
		return callBrittleAPI()
	})
	if err != nil {
		fmt.Println("callBrittleAPI failed after 3 retries: %w", err)
	}

	f := "config.json"
	if !gotoolbox.IsDirectory(f) && gotoolbox.FileExists(f) {
		config, err := gotoolbox.ReadJSONFile(f)
		if err != nil {
			fmt.Println("error reading json file: %w", err)
		}
	}

	value := gotoolbox.GetEnvWithDefault("MY_ENVVAR", "true")

	command := exec.Command("docker", "build", "-t", "foo", ".")
	err = gotoolbox.ExecCmd(command, true)
	if err != nil {
		fmt.Println("error executing command: %w", err)
	}

	var data interface{}
	err = gotoolbox.HttpGetJSON("https://api.example.com/data.json", &data)
	err = gotoolbox.HttpPostJSON("https://api.example.com/data.json", data, http.StatusOK)
}

web package

package main

import (
	"embed"
	"html/template"
	"net/http"
	"github.com/jritsema/gotoolbox/web"
)

var (
	//go:embed all:templates/*
	templateFS embed.FS
	html *template.Template
)

type Data struct {
	Hello string `json:"hello"`
}

func index(r *http.Request) *web.Response {
	return HTML(http.StatusOK, html, "index.html", Data{Hello: "world"}, nil)
}

func api(r *http.Request) *web.Response {
	return web.DataJSON(http.StatusOK, Data{Hello: "world"}, nil)
}

func main() {
	html, _ = web.TemplateParseFSRecursive(templateFS, ".html", true, nil)
	mux := http.NewServeMux()
	mux.Handle("/api", web.Action(api))
	mux.Handle("/", web.Action(index))
	http.ListenAndServe(":8080", mux)
}

development

Choose a make command to run

vet vet code
test run unit tests
build build a binary
autobuild auto build when source files change
start build and run local project

Documentation

Index

• func ExecCmd(cmd *exec.Cmd, output bool) error
• func FileExists(filename string) bool
• func GetEnvWithDefault(key, defaultValue string) string
• func HttpGetJSON(url string, result interface{}) error
• func HttpPostJSON(url string, o interface{}, httpStatusCodeToCheck int) error
• func HttpPutJSON(url string, o interface{}) error
• func IsDirectory(path string) (bool, error)
• func ReadJSONFile(fileName string) (map[string]string, error)
• func Retry(attempts int, sleep time.Duration, fn func() error) error
• func SliceContains(s *[]string, e string) bool
• func SliceContainsInt(i *[]int, e int) bool
• func SliceContainsLike(s *[]string, e string) bool
• type Stop

Functions

func ExecCmd

func ExecCmd(cmd *exec.Cmd, output bool) error

ExecCmd executes a command and waits

func FileExists

func FileExists(filename string) bool

FileExists returns true if a file exists

func GetEnvWithDefault

func GetEnvWithDefault(key, defaultValue string) string

GetEnvWithDefault returns the value of an enviornment variable or a default value if the environment variables is not set

func HttpGetJSON

func HttpGetJSON(url string, result interface{}) error

HttpGetJSON fetches the contents of the given URL and decodes it as JSON into the given result, which should be a pointer to the expected data. returns an error if http response code is not 200

func HttpPostJSON

func HttpPostJSON(url string, o interface{}, httpStatusCodeToCheck int) error

HttpPostJSON encodes a struct as JSON and HTTP POSTs it to the specified endpoint returns an error if http response code does not match specified

func HttpPutJSON

func HttpPutJSON(url string, o interface{}) error

HttpPutJSON encodes a struct as JSON and HTTP PUTs it to the specified endpoint returns an error if http response code is not 200

func IsDirectory

func IsDirectory(path string) (bool, error)

IsDirectory returns true if a path is a directory

func ReadJSONFile

func ReadJSONFile(fileName string) (map[string]string, error)

ReadJSONFile reads JSON from a file

func Retry

func Retry(attempts int, sleep time.Duration, fn func() error) error

Retry retries a function with exponential backoff return a Stop error to abort

func SliceContains

func SliceContains(s *[]string, e string) bool

SliceContains returns true if a slice contains a string

func SliceContainsInt

func SliceContainsInt(i *[]int, e int) bool

SliceContainsInt returns true if a slice contains an int

func SliceContainsLike

func SliceContainsLike(s *[]string, e string) bool

SliceContainsLike returns true if a slice contains a string that contains another string

Types

type Stop

type Stop struct {
	// contains filtered or unexported fields
}

Stop represents a stop error