Python Gunicorn导入错误：没有名为app的模块

我编写了一个dockerfile，正在运行

docker build-t测试。

但我在最后一行得到了这个错误

Step 15/16 : WORKDIR "/API"
 ---> Using cache
 ---> c09969ab4023
Step 16/16 : RUN gunicorn -b localhost:5000 app
 ---> Running in 69c1859e7ba5
[2019-10-15 11:34:17 +0000] [7] [INFO] Starting gunicorn 19.9.0
[2019-10-15 11:34:17 +0000] [7] [INFO] Listening at: http://127.0.0.1:5000 (7)
[2019-10-15 11:34:17 +0000] [7] [INFO] Using worker: sync
[2019-10-15 11:34:17 +0000] [11] [INFO] Booting worker with pid: 11
[2019-10-15 11:34:17 +0000] [11] [ERROR] Exception in worker process
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/gunicorn/arbiter.py", line 583, in spawn_worker
    worker.init_process()
  File "/usr/local/lib/python2.7/dist-packages/gunicorn/workers/base.py", line 129, in init_process
    self.load_wsgi()
  File "/usr/local/lib/python2.7/dist-packages/gunicorn/workers/base.py", line 138, in load_wsgi
    self.wsgi = self.app.wsgi()
  File "/usr/local/lib/python2.7/dist-packages/gunicorn/app/base.py", line 67, in wsgi
    self.callable = self.load()
  File "/usr/local/lib/python2.7/dist-packages/gunicorn/app/wsgiapp.py", line 52, in load
    return self.load_wsgiapp()
  File "/usr/local/lib/python2.7/dist-packages/gunicorn/app/wsgiapp.py", line 41, in load_wsgiapp
    return util.import_app(self.app_uri)
  File "/usr/local/lib/python2.7/dist-packages/gunicorn/util.py", line 350, in import_app
    __import__(module)
ImportError: No module named app
[2019-10-15 11:34:17 +0000] [11] [INFO] Worker exiting (pid: 11)
[2019-10-15 11:34:17 +0000] [7] [INFO] Shutting down: Master
[2019-10-15 11:34:17 +0000] [7] [INFO] Reason: Worker failed to boot.
The command '/bin/sh -c gunicorn -b localhost:5000 app' returned a non-zero code: 3

我怎么知道我做错了什么，因为我调试失败了，而且我没有docker的经验，实际上只是个初学者。我怀疑它可能是我所在的错误目录，或者不是？虽然我确信

cdapi/

是正确的，但我应该在这里

具有依赖项（如Caffe）的python项目的my Dockerfile：

FROM ubuntu:18.04
RUN apt-get update -y && apt-get install -y python-pip python-virtualenv tesseract-ocr poppler-utils

#Install dependencies:
COPY requirements.txt .
RUN pip install -r requirements.txt

ENV DEBIAN_FRONTEND=noninteractive

RUN apt-get update && apt-get install -y --no-install-recommends \
        build-essential \
        cmake \
        git \
        wget \
        libatlas-base-dev \
        libboost-all-dev \
        libgflags-dev \
        libgoogle-glog-dev \
        libhdf5-serial-dev \
        libleveldb-dev \
        liblmdb-dev \
        libopencv-dev \
        libprotobuf-dev \
        libsnappy-dev \
        protobuf-compiler \
        python-dev \
        python-numpy \
        python-pip \
        python-setuptools \
        python-scipy && \
    rm -rf /var/lib/apt/lists/*

ENV CAFFE_ROOT=/opt/caffe
WORKDIR $CAFFE_ROOT

# FIXME: use ARG instead of ENV once DockerHub supports this
# https://github.com/docker/hub-feedback/issues/460
ENV CLONE_TAG=1.0

RUN git clone -b ${CLONE_TAG} --depth 1 https://github.com/BVLC/caffe.git . && \
#    pip install --upgrade pip && \
    cd python && for req in $(cat requirements.txt) pydot; do pip install $req; done && cd .. && \
    mkdir build && cd build && \
    cmake -DCPU_ONLY=1 .. && \
    make -j"$(nproc)"

ENV PYCAFFE_ROOT $CAFFE_ROOT/python
ENV PYTHONPATH $PYCAFFE_ROOT:$PYTHONPATH
ENV PATH $CAFFE_ROOT/build/tools:$PYCAFFE_ROOT:$PATH
RUN echo "$CAFFE_ROOT/build/lib" >> /etc/ld.so.conf.d/caffe.conf && ldconfig

#WORKDIR /workspace

#Run
WORKDIR "/API"
RUN gunicorn -b localhost:5000 app

---

通过在

运行之前添加：
复制API/API
，解决了这一问题
WORKDIR“/API”

在

运行之前添加：
复制API/API
WORKDIR“/API”