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Use Docker to start Localhost connection from Device to AWS EC2 Instance

I’ve been unable to use Docker to connect to a localhost on an AWS EC2 instance (and I’ve been trying for 4 days now).

I’m running an AWS Linux EC2 Instance, where I’ve already installed all the dependencies, uploaded the 1 python script with the helper functions that utilize these dependencies (, and the FastAPI script ( My directory is called r_app, and it looks like: __pycache__ Dockerfile leptonica-1.75.1 photo_1.jpg

I am trying to setup this FastAPI script for production testing purposes, and it has only 1 API call. I want to get my 1 API POST call (that utilizes my helper functions) running and available for access on my brower’s localhost (so connecting to the EC2 Instance).
Inside of

from fastapi import FastAPI, File, UploadFile, Form
from pydantic import BaseModel

import numpy as np
import cv2
from helper_functions import process_image 
app = FastAPI()'/file')
def _file_upload(
        my_file: UploadFile = File(...),
        width: int = Form(...),
        height: int = Form(...),

    image_bytes =
    decoded = cv2.imdecode(np.frombuffer(image_bytes, np.uint8), -1)
    pg_image = cv2.resize(decoded, (width, height))
    new_dict = process_image() 
    return {
        "name": my_file.filename,
        "new_dict": new_dict

I entered the following in my Dockerfile:

FROM ubuntu:18.04
CMD ["ubuntu", ""]

(I have no COPY or RUN statements since I have already manually included all the neccessary dependencies and files in my EC2 instance)

But after I build the image container, and when I run this in the command line

docker run -t -i -p 80:80 getting_started
I get the error
docker: Error response from daemon: OCI runtime create failed: container_linux.go:380: starting container process caused: exec: "ubuntu": executable file not found in $PATH: unknown.

Any help or suggestions is appreciated; thanks so much for helping me clear this roadblock!

Are you sure about the Dockerfile?

Neither any file ( is copied into the image, nor is “ubuntu” an existing command in the container…