proxy.go

package main

import (
	"fmt"
	"github.com/gin-gonic/gin"
	"io/ioutil"
	"net/http"
)

func getImage(c *gin.Context) {
	targetURL := c.Query("q")
	if targetURL == "" {
		c.String(http.StatusBadRequest, "?q=<target url> is required")
		return
	}

	client := &http.Client{}
	req, err := http.NewRequest("GET", targetURL, nil)
	if err != nil {
		c.String(http.StatusInternalServerError, err.Error())
		return
	}
	req.Header.Set("User-Agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 11_1_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36")

	resp, err := client.Do(req)
	if err != nil {
		c.String(http.StatusInternalServerError, err.Error())
		return
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		c.String(http.StatusBadRequest, fmt.Sprintf("status code is %d", resp.StatusCode))
		return
	}

	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		c.String(http.StatusInternalServerError, err.Error())
		return
	}

	contentType := http.DetectContentType(body)

	c.Data(http.StatusOK, contentType, body)
}