如何使用 python 请求将 OpenCV 图像发送到 Go 端点

Question

Here is the code for my camera script

import cv2
import requests
from datetime import datetime
from time import sleep

def sendImage(frame):
    imencoded = cv2.imencode(".jpg", frame)[1]
    now = datetime.now()
    seq = now.strftime("%Y%m%d%H%M%S")
    file = {'file': (seq+'.jpg', imencoded.tobytes(), 'image/jpeg')}
    response = requests.post("https://noeldev.site/cam", files=file, timeout=5)
    return response

def takeImage():
    cap = cv2.VideoCapture(0)
    ret, frame = cap.read()
    print(sendImage(frame))
    cap.release()


while 1:
    takeImage()
    sleep(5)

and my Go Server

package main

import (
    "fmt"
    "log"
    "net/http"

    "github.com/gorilla/mux"
)

func imgHandler(w http.ResponseWriter, r *http.Request) {
    fmt.Println("recieved request!")

    r.ParseMultipartForm(10 << 20)

    file, handler, err := r.FormFile("myFile")

    if err != nil {
        fmt.Println("error!")
        return
    }

    defer file.Close()
    fmt.Println(handler.Filename)
}

func getHandler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "Hello World API!")
}

func main() {
    r := mux.NewRouter()

    r.HandleFunc("/", imgHandler).Methods("POST")
    r.HandleFunc("/", getHandler).Methods("GET")

    http.Handle("/", r)

    log.Fatal(http.ListenAndServe(":3004", nil))
}

I have no idea why I keep on getting an error on my FormFile function. My end goal is to have a secure connection to an endpoint so that I can send images from my raspberry pi to my server and have it saved locally. How can I do this so I send files to my Go endpoint using the python requests library. I've already seen solutions that involve using elements on a html page that works.

Answer 1

In Python you call the field file where in Go you try to access myFile . The change to the Go code was:

file, handler, err := r.FormFile("file")

To find this out, I've changed the debug line to print the error as well:

if err != nil {
    fmt.Printf("error: %s\n", err)
    return
}

(In general, use log.Printf in servers:)