added docker as a runtime option

Dockerfile

@@ -0,0 +1,17 @@
+# official python image 
+FROM python:3.9-slim 
+
+# setting working dir
+WORKDIR /localfiletransfer
+
+# copy flask app in to the container
+COPY . /localfiletransfer
+
+# installing requirements
+RUN pip install --no-cache-dir -r requirements.txt
+
+# exposing port 5000
+EXPOSE 5000
+
+# command to run the app
+CMD [ "python3", "app.py" ]

app.py

@@ -55,16 +55,10 @@ def download_file(filename):
     return response
 
 def get_ip():
-    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
     try:
-        # doesn't even have to be reachable
-        s.connect(('10.255.255.255', 1))
-        IP = s.getsockname()[0]
-    except Exception:
-        IP = '127.0.0.1'
-    finally:
-        s.close()
-    return IP
+        return socket.gethostbyname("host.docker.internal")    # Host IP For macOS and Windows
+    except:
+        return socket.gethostbyname(socket.gethostname())  # Host IP For Linux
 
 def generate_qr_code(url):
     qr = qrcode.QRCode(

docker-compose.yml

@@ -0,0 +1,22 @@
+version: '3.9'
+
+services:
+
+  web_windows: # service for Windows/Mac
+    build: .
+    volumes:
+      - ./uploads:/localfiletransfer/uploads
+      - ./downloads:/localfiletransfer/downloads
+    ports:
+      - "5000:5000" # Required for macOS/Windows to expose the container port
+    profiles:
+      - "windows_mac" # Profile name for macOS/Windows
+
+  web_linux: # service for Linux
+    build: .
+    volumes:
+      - ./uploads:/localfiletransfer/uploads
+      - ./downloads:/localfiletransfer/downloads
+    network_mode: "host" # Linux host network mode
+    profiles:
+      - "linux" # Profile name for Linux