main.go

package main

import (
	"fmt"
	"net/http"
)

// This code can be found at: https://git.io/JvuTw

func main() {
	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Add("Content-Type", "text/html")
		fmt.Fprintf(w, `
			<form action="/upload" method="POST" enctype="multipart/form-data">
				<input type="file" name="file">
				<input type="submit">
			</form>
		`)
	})

	http.HandleFunc("/upload", func(w http.ResponseWriter, r *http.Request) {
		file, _, err := r.FormFile("file")
		if err != nil {
			http.Error(w, fmt.Sprintf("file error: %v", err), http.StatusBadRequest)
			return
		}

		// 1. Return the size of the uploaded image (as plain text).
		// 2. Add a JSON response that returns the size of the uploaded file.
		//    Tip: use ioutil.ReadAll to read the file into a []byte.
		// 3. Add the MD5 of the image to the response
		//    Tip: https://golang.org/pkg/crypto/md5/#Sum
		// 4. Add the image dimensions to the output.
		//    Tip: https://golang.org/pkg/image/png/
	})

	err := http.ListenAndServe(":8080", nil)
	if err != nil {
		panic(err)
	}
}