Example with custom authentication and authorization with echo go web framework

server.go

package main

import (
	"fmt"
	"github.com/dgrijalva/jwt-go"
	"github.com/labstack/echo"
	"github.com/labstack/echo/middleware"
	"net/http"
	"time"
)

type User struct {
	Username string `json:"username"`
	Password string `json:"password"`
}

func login(c echo.Context) error {
	user := User{}
	if err := c.Bind(&user); err != nil {
		return echo.NewHTTPError(http.StatusBadRequest, err.Error())
	}

	if user.Username != "jon" || user.Password != "shhh!" {
		return echo.ErrUnauthorized
	}

	token, err := createToken("John snow", []string{"admin"})
	if err != nil {
		return err
	}

	return c.JSON(http.StatusOK, map[string]string{
		"token": token,
	})
}

func createToken(name string, roles []string) (string, error) {
	token := jwt.New(jwt.SigningMethodHS256)
	claims := token.Claims.(jwt.MapClaims)
	claims["name"] = name
	claims["roles"] = roles
	claims["exp"] = time.Now().Add(time.Hour * 24 * 10).Unix()
	t, err := token.SignedString([]byte("secret"))
	return t, err
}

func accessible(c echo.Context) error {
	return c.String(http.StatusOK, "Accessible")
}

func restricted(c echo.Context) error {
	user := c.Get("user").(*jwt.Token)
	claims := user.Claims.(jwt.MapClaims)
	name := claims["name"].(string)
	roles := claims["roles"].([]interface{})
	return c.String(http.StatusOK,
		fmt.Sprintf("Welcome %s, you have roles: %v\n", name, roles))
}

func SkipperFn(skipURLs []string) func(echo.Context) bool {
	return func(context echo.Context) bool {
		for _, url := range skipURLs {
			if url == context.Request().URL.String() {
				return true
			}
		}
		return false
	}
}

func main() {
	e := echo.New()

	// Middleware
	e.Use(middleware.Recover())
	e.Use(middleware.Logger())
	e.Use(middleware.JWTWithConfig(middleware.JWTConfig{
		SigningKey: []byte("secret"),
		Skipper:    SkipperFn([]string{"/api/v1/login", "/"}),
	}))

	// Login route
	e.POST("/api/v1/login", login)
	e.GET("/", accessible)

	e.GET("/api/v1/me", restricted)

	e.Logger.Fatal(e.Start(":8000"))
}