ModuleNotFoundError: No module named 'app'

[anravi]

FROM <using centos8>
USER root
RUN dnf -y update && \
    dnf -y install gcc && \
    dnf -y groupinstall "Development Tools" && \
    dnf -y install python3 && \
    dnf -y install python3-devel && \
    pip3 install fastapi && \
    pip3 install uvicorn

EXPOSE 8080
COPY ./app /app
CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "8080"]

from fastapi import FastAPI
app = FastAPI()

@app.get("/")
def read_root():
    return {"Hello": "World"}

@app.get("/items/{item_id}")
def read_item(item_id: int, q: str = None):
    return {"item_id": item_id, "q": q}

exception container log:

Traceback (most recent call last):
  File "/usr/local/bin/uvicorn", line 11, in <module>
    sys.exit(main())
  File "/usr/local/lib/python3.6/site-packages/click/core.py", line 829, in __call__
    return self.main(*args, **kwargs)
  File "/usr/local/lib/python3.6/site-packages/click/core.py", line 782, in main
    rv = self.invoke(ctx)
  File "/usr/local/lib/python3.6/site-packages/click/core.py", line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/local/lib/python3.6/site-packages/click/core.py", line 610, in invoke
    return callback(*args, **kwargs)
  File "/usr/local/lib/python3.6/site-packages/uvicorn/main.py", line 331, in main
    run(**kwargs)
  File "/usr/local/lib/python3.6/site-packages/uvicorn/main.py", line 354, in run
    server.run()
  File "/usr/local/lib/python3.6/site-packages/uvicorn/main.py", line 382, in run
    loop.run_until_complete(self.serve(sockets=sockets))
  File "uvloop/loop.pyx", line 1456, in uvloop.loop.Loop.run_until_complete
  File "/usr/local/lib/python3.6/site-packages/uvicorn/main.py", line 389, in serve
    config.load()
  File "/usr/local/lib/python3.6/site-packages/uvicorn/config.py", line 288, in load
    self.loaded_app = import_from_string(self.app)
  File "/usr/local/lib/python3.6/site-packages/uvicorn/importer.py", line 23, in import_from_string
    raise exc from None
  File "/usr/local/lib/python3.6/site-packages/uvicorn/importer.py", line 20, in import_from_string
    module = importlib.import_module(module_str)
  File "/usr/lib64/python3.6/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 994, in _gcd_import
  File "<frozen importlib._bootstrap>", line 971, in _find_and_load
  File "<frozen importlib._bootstrap>", line 941, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "<frozen importlib._bootstrap>", line 994, in _gcd_import
  File "<frozen importlib._bootstrap>", line 971, in _find_and_load
  File "<frozen importlib._bootstrap>", line 953, in _find_and_load_unlocked
ModuleNotFoundError: No module named 'app'

[tiangolo]

Hey @anravi , please follow the template, review all the checks, etc.

Anyway, you would probably have to make /app your working directory in your Dockerfile:

WORKDIR /app/

You could probably also use the official Docker image: https://github.com/tiangolo/uvicorn-gunicorn-fastapi-docker

[github-actions[bot]]

Assuming the original issue was solved, it will be automatically closed now. But feel free to add more comments or create new issues.

[jhaggle]

I get the same error.
Make /app your working directory in the Dockerfile does not change this.

[tiangolo]

@jhaggle that might be related to a lot of different ways your Python is not finding the app module.

For example, if the directory /app already exists in the image, then doing:

COPY ./app /app

will actually copy ./app into the container at /app/app instead of /app.

But again, that will depend on each case and each Dockerfile.

You can probably follow the instructions of the official Docker images and/or copy or replicate what they do.

Otherwise, if you have a minimal, self-contained example that reproduces your error, please create a new issue following all the steps in the issue template.