app.py: introduce free tier

app.py

@@ -7,6 +7,8 @@ Voice Conversion service interactive demo
 import glob
 import logging
 import os
+import socket
+from typing import Dict
 
 import gradio as gr
 
@@ -14,6 +16,25 @@ from vc_service_request import vc_service_request
 
 script_dir = os.path.dirname(os.path.abspath(__file__))
 counter = 0
+# dict to limit max numer of usages per user without API key
+# clears up on demo restart, but thats ok for now
+users: Dict[str, int] = {}
+FREE_TIER = 3
+
+
+def get_ip(request: gr.Request) -> str:
+    """
+    returns user IP from request
+    as in https://huggingface.co/spaces/radames/gradio-request-get-client-ip/blob/main/app.py
+    """
+    client_ip = request.client.host
+    local_ip = socket.gethostbyname(socket.gethostbyname(""))
+    headers = request.kwargs['headers']
+    if headers and 'x-forwarded-for' in headers:
+        x_forwarded_for = headers['x-forwarded-for']
+        client_ip = x_forwarded_for.split(' ')[0] if x_forwarded_for else ""
+    return client_ip
+
 
 def main():
     logging.basicConfig(level=logging.INFO)
@@ -56,7 +77,10 @@ def main():
             """
         )
         gr.Markdown(badges)
-
+        with gr.Row():
+            apikey = gr.Textbox(label="API key", placeholder="Enter API key or leave empty for a free tier")
+        with gr.Row():
+            apisecret = gr.Textbox(label="API secret", placeholder="Enter API secret or leave empty for a free tier")
         with gr.Row():
             with gr.Column(variant="panel"):
                 src_audio_mic = gr.Audio(source="microphone", label="Record your voice")
@@ -81,7 +105,7 @@ def main():
         with gr.Row():
             result_audio = gr.Audio()
 
-        def voice_conversion(src_from_mic_, src_from_file_, tgt_from_file_):
+        def voice_conversion(src_from_mic_, src_from_file_, tgt_from_file_, api_key_, api_secret_, request_: gr.Request):
             """
             helper function which checks where source come from
             """
@@ -93,15 +117,28 @@ def main():
             tgt_ = tgt_from_file_
             if not src_ or not tgt_:
                 logging.warning("source or target are not provided")
+                gr.Warning("Source or target audio are not provided")
                 return
-            global counter
-            logging.info(f"Making conversion request: [{counter}]")
+            global counter, users
+            ip_ = get_ip(request_)
+            past_requests_ = users.get(ip_, 0)
+            free_tier_ = False
+            if not api_key_ or not api_secret_:
+                free_tier = True
+                api_key_ = os.environ["api_key"]
+                api_secret_ = os.environ["api_secret"]
+            if free_tier and past_requests_ >= FREE_TIER:
+                gr.Warning("Free tier exceeded, please reach out to get your API key")
+                logging.info(f"Free tier exceeded for {ip_}")
+                return None
+            logging.info(f"Total number of requests: {counter}. {past_requests_} for {ip_}")
             counter += 1
-            return vc_service_request(src_, tgt_)
+            users[ip_] = past_requests_ + 1
+            return vc_service_request(src_, tgt_, api_key_, api_secret_)
 
         convert_btn.click(
             voice_conversion,
-            inputs=[src_audio_mic, src_audio_file, tgt_audio_file],
+            inputs=[src_audio_mic, src_audio_file, tgt_audio_file, apikey, apisecret],
             outputs=result_audio,
         )