10 - Asyncio Subprocess & Websockets

Author: codingforentrepreneurs

client.py

@@ -7,10 +7,10 @@
 async def connect_to_ws(msg):
     async with websockets.connect(websocket_endpoint) as ws:
         await ws.send(msg)
-        async for message in ws:
-            print(message)
-            await asyncio.sleep(10)
-            await ws.close()
+        # async for message in ws:
+        #     print(message)
+            # await asyncio.sleep(10)
+        #   await ws.close()
 
 if __name__=="__main__":
     msg = 'nothing here'

index.py

@@ -2,21 +2,44 @@
 import websockets
 import json
 
-async def webhook_handler(websocket, path):
-    print(websocket, path)
+
+async def call_cli_command(cmd):
+    '''
+    python client.py '{"cell_data": "print(\"hello world\")"}'
+    python client.py '{"cell_data": "print(134243 * 234234)"}'
+    python client.py '{"cell_data": "!pip freeze"}'
+    '''
+    command_args = ['python', '-c', cmd] # ['python', '-c', 'print("hello world")'] 
+    if cmd.startswith("!"): # !pip install fastapi
+        command_args = cmd[1:].split()
+    proc = await asyncio.create_subprocess_exec(
+        *command_args,
+        stdout=asyncio.subprocess.PIPE,
+        stderr=asyncio.subprocess.PIPE,
+    )
+    stdout, stderr = await proc.communicate()
+    return stdout.decode("utf-8"), stderr.decode("utf-8")
+
+
+async def websocket_handler(websocket, path):
+    # print(websocket, path)
     async for message in websocket:
         data = {}
         try:
             data = json.loads(message)
         except:
             pass
-        print(data.get('data'))
-        await websocket.send(json.dumps({"this": "awesome"}))
+        # print(data.get('cell_data'))
+        cell_data = data.get("cell_data")
+        if cell_data != None:
+            stdout, stderr = await call_cli_command(cell_data)
+            print(stdout, stderr)
+        # await websocket.send(json.dumps({"this": "awesome"}))
         # print(message)
     # pass
 
 
-server = websockets.serve(webhook_handler, 'localhost', 8765)
+server = websockets.serve(websocket_handler, 'localhost', 8765)
 
 loop = asyncio.get_event_loop()
 loop.run_until_complete(server)

reference_examples/subproc.py

@@ -0,0 +1,8 @@
+import subprocess
+
+process = subprocess.Popen(['pip', 'freeze'], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+
+stdout, stderr = process.communicate()
+
+print(stdout.decode('utf-8'))
+# print(stderr.decode('utf-8'))