Golang Upload -> Resize -> Return modified image

curl.sh

curl -F "file=@input.jpg" http://localhost:8080/upload --output result.jpg

server.go

package main

import (
    "fmt"
    "io/ioutil"
    "net/http"
    "os"

    "github.com/h2non/bimg"
)

func uploadFile(w http.ResponseWriter, r *http.Request) {
    fmt.Println("File Upload Endpoint Hit")

    // Parse our multipart form, 10 << 20 specifies a maximum
    // upload of 10 MB files.
    r.ParseMultipartForm(10 << 20)
    // FormFile returns the first file for the given key `myFile`
    // it also returns the FileHeader so we can get the Filename,
    // the Header and the size of the file
    file, handler, err := r.FormFile("file")
    if err != nil {
        fmt.Println("Error Retrieving the File")
        fmt.Println(err)
        return
    }
    defer file.Close()

    byteContainer, err := ioutil.ReadAll(file)

    newImage, err := bimg.NewImage(byteContainer).Resize(320, 240)
    if err != nil {
        fmt.Fprintln(os.Stderr, err)
    }

    w.Header().Set("Content-Type", handler.Header["Content-Type"][0])

    w.Write(newImage)
}

func setupRoutes() {
    http.HandleFunc("/upload", uploadFile)
    http.ListenAndServe(":8080", nil)
}

func main() {
    fmt.Println("Hello World")
    setupRoutes()
}