Unable to send json request when using fastapi - json

Question

I have error in the following code when I try to send a request with json data in it, is it because it only works synchronously, so does not work in fastapi which work asynchronously? If that is the case, what is the simplest way to send a request with json data in it?
import time
from fastapi import Request, FastAPI, BackgroundTasks
import multiprocessing as mp
import uvicorn
import requests
import json
def printmessage(job):
time.sleep(5)
print(job)
if __name__ == 'webhook_fastapi':
url = 'http://127.0.0.1:8000/webhook'
data = { 'text': 'hello'}
r = requests.post(url, data=json.dumps(data), headers={'Content-Type': 'application/json'})
print("Request Sent!")
app = FastAPI()
#app.post("/webhook")
async def webhook(request : Request, background_tasks: BackgroundTasks):
print("WEBHOOK RECEIVED")
job="doctor"
background_tasks.add_task(printmessage,job)
print('done')
return 'WEBHOOK RECEIVED'
if __name__ == '__main__':
print("PROGRAM LAUNCH...")
print("WEBHOOK RECEIVE READY...")
background_tasks = BackgroundTasks()
job="doctor"
background_tasks.add_task(printmessage,job)
uvicorn.run("webhook_fastapi:app", reload=False)
OUTPUT:
__main__
PROGRAM LAUNCH...
WEBHOOK RECEIVE READY...
webhook_fastapi
Traceback (most recent call last): File
"C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\urllib3\connection.py",
line 169, in _new_conn
conn = connection.create_connection( File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\urllib3\util\connection.py",
line 96, in create_connection
raise err File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\urllib3\util\connection.py",
line 86, in create_connection
sock.connect(sa) ConnectionRefusedError: [WinError 10061] No connection could be made because the target machine actively refused
it
During handling of the above exception, another exception occurred:
Traceback (most recent call last): File
"C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\urllib3\connectionpool.py",
line 699, in urlopen
httplib_response = self._make_request( File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\urllib3\connectionpool.py",
line 394, in _make_request
conn.request(method, url, **httplib_request_kw) File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\urllib3\connection.py",
line 234, in request
super(HTTPConnection, self).request(method, url, body=body, headers=headers) File
"C:\Users\User\AppData\Local\Programs\Python\Python39\lib\http\client.py",
line 1279, in request
self._send_request(method, url, body, headers, encode_chunked) File
"C:\Users\User\AppData\Local\Programs\Python\Python39\lib\http\client.py",
line 1325, in _send_request
self.endheaders(body, encode_chunked=encode_chunked) File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\http\client.py",
line 1274, in endheaders
self._send_output(message_body, encode_chunked=encode_chunked) File
"C:\Users\User\AppData\Local\Programs\Python\Python39\lib\http\client.py",
line 1034, in _send_output
self.send(msg) File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\http\client.py",
line 974, in send
self.connect() File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\urllib3\connection.py",
line 200, in connect
conn = self._new_conn() File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\urllib3\connection.py",
line 181, in _new_conn
raise NewConnectionError( urllib3.exceptions.NewConnectionError: <urllib3.connection.HTTPConnection object at 0x0000013C0E494310>:
Failed to establish a new connection: [WinError 10061] No connection
could be made because the target machine actively refused it
During handling of the above exception, another exception occurred:
Traceback (most recent call last): File
"C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\requests\adapters.py",
line 439, in send
resp = conn.urlopen( File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\urllib3\connectionpool.py",
line 755, in urlopen
retries = retries.increment( File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\urllib3\util\retry.py",
line 574, in increment
raise MaxRetryError(_pool, url, error or ResponseError(cause)) urllib3.exceptions.MaxRetryError: HTTPConnectionPool(host='127.0.0.1',
port=8000): Max retries exceeded with url: /webhook (Caused by
NewConnectionError('<urllib3.connection.HTTPConnection object at
0x0000013C0E494310>: Failed to establish a new connection: [WinError
10061] No connection could be made because the target machine actively
refused it'))
During handling of the above exception, another exception occurred:
Traceback (most recent call last): File
"c:\Users*\webhook_fastapi.py", line 40, in
uvicorn.run("webhook_fastapi:app", reload=False) File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\uvicorn\main.py",
line 463, in run
server.run() File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\uvicorn\server.py",
line 60, in run
return asyncio.run(self.serve(sockets=sockets)) File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\asyncio\runners.py",
line 44, in run
return loop.run_until_complete(main) File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py",
line 642, in run_until_complete
return future.result() File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\uvicorn\server.py",
line 67, in serve
config.load() File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\uvicorn\config.py",
line 458, in load
self.loaded_app = import_from_string(self.app) File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\uvicorn\importer.py",
line 21, in import_from_string
module = importlib.import_module(module_str) File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\importlib_init_.py",
line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level) File "", line 1030, in _gcd_import File
"", line 1007, in _find_and_load File
"", line 986, in _find_and_load_unlocked
File "", line 680, in _load_unlocked
File "", line 850, in
exec_module File "", line 228, in
_call_with_frames_removed File "c:\Users*\webhook_fastapi.py", line 19, in
r = requests.post(url, data=json.dumps(data), headers={'Content-Type': 'application/json'}) File
"C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\requests\api.py",
line 117, in post
return request('post', url, data=data, json=json, **kwargs) File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\requests\api.py",
line 61, in request
return session.request(method=method, url=url, **kwargs) File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\requests\sessions.py",
line 542, in request
resp = self.send(prep, **send_kwargs) File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\requests\sessions.py",
line 655, in send
r = adapter.send(request, kwargs) File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\requests\adapters.py",
line 516, in send
raise ConnectionError(e, request=request) requests.exceptions.ConnectionError:
HTTPConnectionPool(host='127.0.0.1', port=8000): Max retries exceeded
with url: /webhook (Caused by
NewConnectionError('<urllib3.connection.HTTPConnection object at
0x0000013C0E494310>: Failed to establish a new connection: [WinError
10061] No connection could be made because the target machine actively
refused it')) PS C:\Users*>

Answer 1

There is no server running when you're trying to make your request. uvicorn is importing your code, and you're apparently trying to make a request while the code is being imported.
uvicorn can't launch the API and bind to the port before it has finished importing the code and the ASGI application has been set up and properly configured.