How to use authorizer as API gateway

Note: This example demonstrates how to use authorizer in middleware for a go-gin server. But logic remains the same under the hood, where you can get auth token from header and validate it via authorizer SDK

package main

import (
	"net/http"
	"strings"

	"github.com/authorizerdev/authorizer-go"
	"github.com/gin-gonic/gin"
)

func AuthorizeMiddleware() gin.HandlerFunc {
	return func(c *gin.Context) {
		/**
		  for open routes you can add condition here and just return with c.Next()
		  so that it does not validate token for those routes
		*/

		authHeader := c.Request.Header.Get("Authorization")
		tokenSplit := strings.Split(authHeader, " ")

		defaultHeaders := map[string]string{}
		authorizerClient, err := authorizer.NewAuthorizerClient("YOUR_CLIENT_ID", "YOUR_AUHTORIZER_URL", "OPTIONAL_REDIRECT_URL", defaultHeaders)
		if err != nil {
			// unauthorized
			c.AbortWithStatusJSON(401, "unauthorized")
			return
		}

		if len(tokenSplit) < 2 || tokenSplit[1] == "" {
			// unauthorized
			c.AbortWithStatusJSON(401, "unauthorized")
			return
		}

		res, err := authorizerClient.ValidateJWTToken(&authorizer.ValidateJWTTokenInput{
			TokenType: authorizer.TokenTypeIDToken,
			Token:     tokenSplit[1],
		})
		if err != nil {
			// unauthorized
			c.AbortWithStatusJSON(401, "unauthorized")
			return
		}

		if !res.IsValid {
			// unauthorized
			c.AbortWithStatusJSON(401, "unauthorized")
			return
		}

		c.Next()
	}
}

func main() {
	router := gin.New()
	router.Use(AuthorizeMiddleware())

	router.GET("/ping", func(c *gin.Context) {
		c.JSON(http.StatusOK, gin.H{
			"message": "pong",
		})
	})

	router.Run(":8090")
}

CURL command to test go-gin server created in example

Copy JWT ID token from login response of authorizer login mutation / social media login and replace JWT_TOKEN below

curl --location --request GET 'http://localhost:8090/ping' \
--header 'Authorization: Bearer JWT_TOKEN'