Dockerfile not recognized when trying to create it - docker

Question

I am trying to build a Docker image from a dockerfile command I received from the previous developer:
bash-5.1$ ls
data_collection demo.py examples requirements.txt start.py
demonstrateur.ipynb Dockerfile README.md serious_game test
bash-5.1$ docker build Dockerfile .
Usage: docker build [OPTIONS] PATH | URL | -
Build an image from a Dockerfile
I also tried with
bash-5.1$ docker build -t serious-game:0.0.1 -t serious-game:latest Dockerfile .
and already completely reinstalled docker by following this tutorial but it gave the same error.
Here is my Dockerfile content:
bash-5.1$ cat Dockerfile
FROM nvidia/cuda:10.2-base-ubuntu18.04
MAINTAINER me
EXPOSE 5555
EXPOSE 8886
ENV DEBIAN_FRONTEND noninteractive
ENV WD=/home/serious-game/
WORKDIR ${WD}
# Add git and ssh
RUN apt-get -y update && \
apt-get -y upgrade && \
apt-get -y install git ssh pkg-config python3-pip python3-opencv
# Dépendances python
COPY requirements.txt /requirements.txt
RUN cd / && \
python3 -m pip install --upgrade pip && \
pip3 install -r requirements.txt
CMD ["start.py"]

Answer 1

If you are trying to build an image from a local Dockerfile, given your current bash location is in the same folder where Dockerfile resides - all you have to do is
docker build .

Answer 2

As written in the docs, Docker uses the file named Dockerfile by default. If you want to specify the file you can use the option --file or -f of the docker build command.
In your case you can just use to solve your problem:
docker build -t serious-game:0.0.1 -t serious-game:latest .
But if you want to specify another file named TestDockerfile (example for testing):
docker build -t serious-game:0.0.1 -t serious-game:latest -f TestDockerfile .