Reload Failing with: ERROR: Application startup failed. Exiting.

[doctrino]

Wave SDK Version, OS

0.25.2 Windows

Actual behavior

Running a starter template wave init -> App with header + navigation

While running app, wave run app if I save changes in the app.py the application shuts down,
with the message Error: Application startup failed. Exiting

Full traceback

WARNING: StatReload detected changes in 'app.py'. Reloading... INFO: Started server process [24748] INFO: Waiting for application startup. ERROR: Traceback (most recent call last): File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\anyio\_core\_sockets.py", line 164, in try_connect stream = await asynclib.connect_tcp(remote_host, remote_port, local_address) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\anyio\_backends\_asyncio.py", line 1691, in connect_tcp await get_running_loop().create_connection( File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\asyncio\base_events.py", line 1073, in create_connection raise exceptions[0] File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\asyncio\base_events.py", line 1058, in create_connection sock = await self._connect_sock( ^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\asyncio\base_events.py", line 964, in _connect_sock await self.sock_connect(sock, address) File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\asyncio\selector_events.py", line 633, in sock_connect return await fut ^^^^^^^^^ File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\asyncio\selector_events.py", line 668, in _sock_connect_cb raise OSError(err, f'Connect call failed {address}') ConnectionRefusedError: [Errno 10061] Connect call failed ('127.0.0.1', 10101) The above exception was the direct cause of the following exception: Traceback (most recent call last): File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpcore\_exceptions.py", line 10, in map_exceptions yield File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpcore\backends\asyncio.py", line 111, in connect_tcp stream: anyio.abc.ByteStream = await anyio.connect_tcp( ^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\anyio\_core\_sockets.py", line 222, in connect_tcp raise OSError("All connection attempts failed") from cause OSError: All connection attempts failed During handling of the above exception, another exception occurred: Traceback (most recent call last): File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpx\_transports\default.py", line 60, in map_httpcore_exceptions yield File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpx\_transports\default.py", line 353, in handle_async_request resp = await self._pool.handle_async_request(req) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpcore\_async\connection_pool.py", line 253, in handle_async_request raise exc File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpcore\_async\connection_pool.py", line 237, in handle_async_request response = await connection.handle_async_request(request) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpcore\_async\connection.py", line 86, in handle_async_request raise exc File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpcore\_async\connection.py", line 63, in handle_async_request stream = await self._connect(request) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpcore\_async\connection.py", line 111, in _connect stream = await self._network_backend.connect_tcp(**kwargs) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpcore\backends\auto.py", line 29, in connect_tcp return await self._backend.connect_tcp( ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpcore\backends\asyncio.py", line 109, in connect_tcp with map_exceptions(exc_map): File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\contextlib.py", line 155, in __exit__ self.gen.throw(typ, value, traceback) File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpcore\_exceptions.py", line 14, in map_exceptions raise to_exc(exc) httpcore.ConnectError: All connection attempts failed The above exception was the direct cause of the following exception: Traceback (most recent call last): File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\starlette\routing.py", line 677, in lifespan async with self.lifespan_context(app) as maybe_state: File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\starlette\routing.py", line 566, in __aenter__ await self._router.startup() File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\starlette\routing.py", line 654, in startup await handler() File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\h2o_wave\server.py", line 297, in _register raise exception File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\h2o_wave\server.py", line 281, in _register await self._wave.call( File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\h2o_wave\server.py", line 232, in call return await self._http.post( ^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpx\_client.py", line 1845, in post return await self.request( ^^^^^^^^^^^^^^^^^^^ File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpx\_client.py", line 1530, in request return await self.send(request, auth=auth, follow_redirects=follow_redirects) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpx\_client.py", line 1617, in send response = await self._send_handling_auth( ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpx\_client.py", line 1645, in _send_handling_auth response = await self._send_handling_redirects( ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpx\_client.py", line 1682, in _send_handling_redirects response = await self._send_single_request(request) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpx\_client.py", line 1719, in _send_single_request response = await transport.handle_async_request(request) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpx\_transports\default.py", line 352, in handle_async_request with map_httpcore_exceptions(): File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\contextlib.py", line 155, in __exit__ self.gen.throw(typ, value, traceback) File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-virtual-env-py3.11\Lib\site-packages\httpx\_transports\default.py", line 77, in map_httpcore_exceptions raise mapped_exc(message) from exc httpx.ConnectError: All connection attempts failed ERROR: Application startup failed. Exiting.

Expected behavior

Application reloads with new changes

Steps To Reproduce

1. wave init -> App with header + navigation
2. Start up app wave run app
3. Do a change in app.py and save.
4. Then, you should see the error above.

[mturoci]

Hi @doctrino.

Can you properly visit the app in the browser after the initial wave run (without changes)?

Connect call failed ('127.0.0.1', 10101)

This indicates your Wave server is not reachable or running. Can you verify a waved process is running on port 10101? Assuming you did not change the default port.

Another thing that might help isolate the problem is running the app within a regular virtual env instead of poetry.

[doctrino]

@mturoci Thank you so much for you response.

I attempted a fresh virtual env environment, no poetry, with the same result.

I did some reading, and I think it has do with localhost vs 127.0.0.1. On Windows it seems like Docker maps the 127.0.0.1 to some Docker stuff, as I have the following line in my hosts file

127.0.0.1 kubernetes.docker.internal

Furthermore, when I start up the app I am told to use localhost:10101:

2023/05/06 18:27:38 # ┌──────────────────────────────────────┐
2023/05/06 18:27:38 # │  Running at http://localhost:10101/  
2023/05/06 18:27:38 # └──────────────────────────────────────┘

Shouldn't the reload trigger h2o-wave to connect to localhost:10101 instead of 127.0.0.1:10101?

[mturoci]

On Windows it seems like Docker maps the 127.0.0.1 to some Docker stuff,

Hold on. Are you running within a docker? If so, a further description of your setup will be needed.

/etc/hosts 127.0.0.1 kubernetes.docker.internal

IMO, this is the root problem as your Wave app tries to connect to kubernetes.docker.internal:10101 instead of localhost:10101.

Shouldn't the reload trigger h2o-wave to connect to localhost:10101 instead of 127.0.0.1:10101

localhost is just an alias for 127.0.0.1 by default. However, since your 127.0.0.1 is mapped to kubernetes.docker.internal, you can try setting H2O_WAVE_ADDRESS=http://localhost:10101 env variable (from the default http://127.0.0.1:10101). Assuming there is no localhost mapping in /etc/hosts, it could resolve your problem. What do you see when you visit http://localhost:10101 in your browser (after the app crash)?

[doctrino]

Hold on. Are you running within a docker? If so, a further description of your setup will be needed.

No I am not running within docker, but I have docker installed which apparently has captured 127.0.0.1.

Yes, I agree that /etc/hosts 127.0.0.1 kubernetes.docker.internal the problem. But I wonder if H20 Wave can have the flexibility to not require /etc/hosts 127.0.0.1 localhost.

I tried running with H2O_WAVE_ADDRESS=http://localhost:10101, but the app still crashes upon change, and it seems the application is still trying to connect to 127.0.0.1:10101 as I get the error: ConnectionRefusedError: [Errno 10061] Connect call failed ('127.0.0.1', 10101). When I visit http://localhost:10101 in the browser after crash I get This site cannot be reached, see screenshot below.

Traceback

^CINFO:     Shutting down
INFO:     Waiting for application shutdown.
INFO:     Application shutdown complete.
INFO:     Finished server process [13508]
INFO:     Started server process [6400]
INFO:     Waiting for application startup.
ERROR:    anyio._backends._asyncio.ExceptionGroup: 2 exceptions were raised in the task group:
----------------------------
Traceback (most recent call last):
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\anyio\_core\_sockets.py", line 164, in try_connect
    stream = await asynclib.connect_tcp(remote_host, remote_port, local_address)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\anyio\_backends\_asyncio.py", line 1691, in connect_tcp
    await get_running_loop().create_connection(
  File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\asyncio\base_events.py", line 1073, in create_connection
    raise exceptions[0]
  File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\asyncio\base_events.py", line 1058, in create_connection
    sock = await self._connect_sock(
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\asyncio\base_events.py", line 964, in _connect_sock
    await self.sock_connect(sock, address)
  File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\asyncio\selector_events.py", line 633, in sock_connect
    return await fut
           ^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\asyncio\selector_events.py", line 668, in _sock_connect_cb
    raise OSError(err, f'Connect call failed {address}')
ConnectionRefusedError: [Errno 10061] Connect call failed ('::1', 10101, 0, 0)
----------------------------
Traceback (most recent call last):
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\anyio\_core\_sockets.py", line 164, in try_connect
    stream = await asynclib.connect_tcp(remote_host, remote_port, local_address)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\anyio\_backends\_asyncio.py", line 1691, in connect_tcp
    await get_running_loop().create_connection(
  File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\asyncio\base_events.py", line 1073, in create_connection
    raise exceptions[0]
  File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\asyncio\base_events.py", line 1058, in create_connection
    sock = await self._connect_sock(
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\asyncio\base_events.py", line 964, in _connect_sock
    await self.sock_connect(sock, address)
  File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\asyncio\selector_events.py", line 633, in sock_connect
    return await fut
           ^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\asyncio\selector_events.py", line 668, in _sock_connect_cb
    raise OSError(err, f'Connect call failed {address}')
ConnectionRefusedError: [Errno 10061] Connect call failed ('127.0.0.1', 10101)


The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpcore\_exceptions.py", line 10, in map_exceptions
    yield
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpcore\backends\asyncio.py", line 111, in connect_tcp
    stream: anyio.abc.ByteStream = await anyio.connect_tcp(
                                   ^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\anyio\_core\_sockets.py", line 222, in connect_tcp
    raise OSError("All connection attempts failed") from cause
OSError: All connection attempts failed

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpx\_transports\default.py", line 60, in map_httpcore_exceptions
    yield
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpx\_transports\default.py", line 353, in handle_async_request
    resp = await self._pool.handle_async_request(req)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpcore\_async\connection_pool.py", line 253, in handle_async_request
    raise exc
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpcore\_async\connection_pool.py", line 237, in handle_async_request
    response = await connection.handle_async_request(request)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpcore\_async\connection.py", line 86, in handle_async_request
    raise exc
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpcore\_async\connection.py", line 63, in handle_async_request
    stream = await self._connect(request)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpcore\_async\connection.py", line 111, in _connect
    stream = await self._network_backend.connect_tcp(**kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpcore\backends\auto.py", line 29, in connect_tcp
    return await self._backend.connect_tcp(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpcore\backends\asyncio.py", line 109, in connect_tcp
    with map_exceptions(exc_map):
  File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\contextlib.py", line 155, in __exit__
    self.gen.throw(typ, value, traceback)
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpcore\_exceptions.py", line 14, in map_exceptions
    raise to_exc(exc)
httpcore.ConnectError: All connection attempts failed

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\starlette\routing.py", line 677, in lifespan
    async with self.lifespan_context(app) as maybe_state:
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\starlette\routing.py", line 566, in __aenter__
    await self._router.startup()
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\starlette\routing.py", line 654, in startup
    await handler()
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\h2o_wave\server.py", line 297, in _register
    raise exception
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\h2o_wave\server.py", line 281, in _register
    await self._wave.call(
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\h2o_wave\server.py", line 232, in call
    return await self._http.post(
           ^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpx\_client.py", line 1845, in post
    return await self.request(
           ^^^^^^^^^^^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpx\_client.py", line 1530, in request
    return await self.send(request, auth=auth, follow_redirects=follow_redirects)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpx\_client.py", line 1617, in send
    response = await self._send_handling_auth(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpx\_client.py", line 1645, in _send_handling_auth
    response = await self._send_handling_redirects(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpx\_client.py", line 1682, in _send_handling_redirects
    response = await self._send_single_request(request)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpx\_client.py", line 1719, in _send_single_request
    response = await transport.handle_async_request(request)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpx\_transports\default.py", line 352, in handle_async_request
    with map_httpcore_exceptions():
  File "C:\Users\MyUser\AppData\Local\Programs\Python\Python311\Lib\contextlib.py", line 155, in __exit__
    self.gen.throw(typ, value, traceback)
  File "C:\Users\MyUser\AppData\Local\pypoetry\Cache\virtualenvs\my-env-py3.11\Lib\site-packages\httpx\_transports\default.py", line 77, in map_httpcore_exceptions
    raise mapped_exc(message) from exc
httpx.ConnectError: All connection attempts failed

ERROR:    Application startup failed. Exiting.

Screenshot

[mturoci]

I wonder if H20 Wave can have the flexibility to not require /etc/hosts 127.0.0.1 localhost

Wave is just a process listening on a specific address + port, from which both are configurable. All the underlying networking goes through OS so there is no way to bypass /etc/hosts.

My networking knowledge is pretty limited so I might not be able to give you a proper solution, but I would try picking an available private IP address if localhost is already taken up within /etc/hosts and go from there. Another alternative would be to remove your localhost => docker mapping, which seems odd.