无法在Docker上运行Flask（ModuleNotFoundError）

Question

我一直试图在Docker上运行我的Python API（使用Flask），但是一直遇到这个问题：

ModuleNotFoundError: No module named 'flask'

在具有Docker 19.03.1版本的Mac OS X（10.14.5）上运行此版本，版本74b1e89。

我的Dockerfile看起来像这样：

FROM pytorch/pytorch:1.1.0-cuda10.0-cudnn7.5-runtime

RUN apt-get update && apt-get install -y python3
RUN apt-get install -y python3-pip
RUN apt-get install -y build-essential
RUN python3 --version
RUN pip3 --version

COPY . /app
WORKDIR /app

RUN pip3 install -r requirements.txt
RUN pip3 install flask # just to be sure Flask gets installed
RUN which flask
RUN ls -alh

ENTRYPOINT ["python3"]
CMD ["api.py"]

请注意，我正在扩展PyTorch docker映像，因为我的API将使用PyTorch运行ML模型。 我尝试从其他图像（例如ufoym/deepo但存在相同的Flask错误。

我剥离了api.py文件，使其看起来像这样（在本地运行它没有问题）：

from flask import Flask, request, jsonify
#import classifier # commented out for now because I just want the API to work first

app = Flask(__name__)

@app.route('/', methods=['GET', 'POST'])
def process():
    # TODO
    return 'test'

if __name__ == '__main__':
    app.run(debug=True, host='0.0.0.0')

构建Docker映像时，得到以下输出：

$ docker build -t flower-image-classifier:latest .
Sending build context to Docker daemon  269.9MB
Step 1/14 : FROM pytorch/pytorch:1.1.0-cuda10.0-cudnn7.5-runtime
 ---> 299bfb9e54db
Step 2/14 : RUN apt-get update && apt-get install -y python3
 ---> Running in f1d7db593022
Get:1 http://archive.ubuntu.com/ubuntu xenial InRelease [247 kB]
Get:2 http://security.ubuntu.com/ubuntu xenial-security InRelease [109 kB]
Get:3 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [109 kB]
Get:4 http://archive.ubuntu.com/ubuntu xenial-backports InRelease [107 kB]
Get:5 http://security.ubuntu.com/ubuntu xenial-security/main amd64 Packages [908 kB]
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Get:7 http://archive.ubuntu.com/ubuntu xenial/restricted amd64 Packages [14.1 kB]
Get:8 http://archive.ubuntu.com/ubuntu xenial/universe amd64 Packages [9827 kB]
Get:9 http://security.ubuntu.com/ubuntu xenial-security/restricted amd64 Packages [12.7 kB]
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Get:13 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages [1292 kB]
Get:14 http://archive.ubuntu.com/ubuntu xenial-updates/restricted amd64 Packages [13.1 kB]
Get:15 http://archive.ubuntu.com/ubuntu xenial-updates/universe amd64 Packages [980 kB]
Get:16 http://archive.ubuntu.com/ubuntu xenial-updates/multiverse amd64 Packages [19.1 kB]
Get:17 http://archive.ubuntu.com/ubuntu xenial-backports/main amd64 Packages [7942 B]
Get:18 http://archive.ubuntu.com/ubuntu xenial-backports/universe amd64 Packages [8532 B]
Fetched 16.0 MB in 9s (1744 kB/s)
Reading package lists...
Reading package lists...
Building dependency tree...
Reading state information...
The following additional packages will be installed:
  dh-python file libmagic1 libmpdec2 libpython3-stdlib libpython3.5-minimal
  libpython3.5-stdlib mime-support python3-minimal python3.5 python3.5-minimal
Suggested packages:
  python3-doc python3-tk python3-venv python3.5-venv python3.5-doc
  binfmt-support
The following NEW packages will be installed:
  dh-python file libmagic1 libmpdec2 libpython3-stdlib libpython3.5-minimal
  libpython3.5-stdlib mime-support python3 python3-minimal python3.5
  python3.5-minimal
0 upgraded, 12 newly installed, 0 to remove and 29 not upgraded.
Need to get 4885 kB of archives.
After this operation, 28.4 MB of additional disk space will be used.
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Get:4 http://archive.ubuntu.com/ubuntu xenial/main amd64 mime-support all 3.59ubuntu1 [31.0 kB]
Get:5 http://archive.ubuntu.com/ubuntu xenial/main amd64 libmpdec2 amd64 2.4.2-1 [82.6 kB]
Get:6 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 libpython3.5-stdlib amd64 3.5.2-2ubuntu0~16.04.5 [2134 kB]
Get:7 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 python3.5 amd64 3.5.2-2ubuntu0~16.04.5 [165 kB]
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Get:9 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 dh-python all 2.20151103ubuntu1.1 [74.1 kB]
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debconf: delaying package configuration, since apt-utils is not installed
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Preparing to unpack .../libmpdec2_2.4.2-1_amd64.deb ...
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Processing triggers for libc-bin (2.23-0ubuntu11) ...
Setting up libpython3.5-minimal:amd64 (3.5.2-2ubuntu0~16.04.5) ...
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Processing triggers for libc-bin (2.23-0ubuntu11) ...
Setting up mime-support (3.59ubuntu1) ...
Setting up libmpdec2:amd64 (2.4.2-1) ...
Setting up libpython3.5-stdlib:amd64 (3.5.2-2ubuntu0~16.04.5) ...
Setting up python3.5 (3.5.2-2ubuntu0~16.04.5) ...
Setting up libpython3-stdlib:amd64 (3.5.1-3) ...
Setting up libmagic1:amd64 (1:5.25-2ubuntu1.2) ...
Setting up file (1:5.25-2ubuntu1.2) ...
Setting up python3 (3.5.1-3) ...
running python rtupdate hooks for python3.5...
running python post-rtupdate hooks for python3.5...
Setting up dh-python (2.20151103ubuntu1.1) ...
Processing triggers for libc-bin (2.23-0ubuntu11) ...
Removing intermediate container f1d7db593022
 ---> 562a488914b2
Step 3/14 : RUN apt-get install -y python3-pip
 ---> Running in 3884de8e3194
Reading package lists...
Building dependency tree...
Reading state information...
The following additional packages will be installed:
  libexpat1 libexpat1-dev libpython3-dev libpython3.5 libpython3.5-dev
  python-pip-whl python3-dev python3-pkg-resources python3-setuptools
  python3-wheel python3.5-dev
Suggested packages:
  python-setuptools-doc
The following NEW packages will be installed:
  libexpat1-dev libpython3-dev libpython3.5 libpython3.5-dev python-pip-whl
  python3-dev python3-pip python3-pkg-resources python3-setuptools
  python3-wheel python3.5-dev
The following packages will be upgraded:
  libexpat1
1 upgraded, 11 newly installed, 0 to remove and 28 not upgraded.
Need to get 40.7 MB of archives.
After this operation, 62.4 MB of additional disk space will be used.
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Get:2 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 libexpat1-dev amd64 2.1.0-7ubuntu0.16.04.4 [115 kB]
Get:3 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 libpython3.5 amd64 3.5.2-2ubuntu0~16.04.5 [1360 kB]
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Get:10 http://archive.ubuntu.com/ubuntu xenial/main amd64 python3-pkg-resources all 20.7.0-1 [79.0 kB]
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Get:12 http://archive.ubuntu.com/ubuntu xenial/universe amd64 python3-wheel all 0.29.0-1 [48.1 kB]
debconf: delaying package configuration, since apt-utils is not installed
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Processing triggers for libc-bin (2.23-0ubuntu11) ...
Setting up libexpat1:amd64 (2.1.0-7ubuntu0.16.04.4) ...
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Setting up libpython3.5:amd64 (3.5.2-2ubuntu0~16.04.5) ...
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Setting up python3.5-dev (3.5.2-2ubuntu0~16.04.5) ...
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Setting up python3-pkg-resources (20.7.0-1) ...
Setting up python3-setuptools (20.7.0-1) ...
Setting up python3-wheel (0.29.0-1) ...
Processing triggers for libc-bin (2.23-0ubuntu11) ...
Removing intermediate container 3884de8e3194
 ---> 388a6aa0bb5f
Step 4/14 : RUN apt-get install -y build-essential
 ---> Running in 2e8c8dc95d9e
Reading package lists...
Building dependency tree...
Reading state information...
build-essential is already the newest version (12.1ubuntu2).
0 upgraded, 0 newly installed, 0 to remove and 28 not upgraded.
Removing intermediate container 2e8c8dc95d9e
 ---> 3c08d3467777
Step 5/14 : RUN python3 --version
 ---> Running in 027dcf1dc8b6
Python 3.6.8 :: Anaconda, Inc.
Removing intermediate container 027dcf1dc8b6
 ---> 0a8389f2fe13
Step 6/14 : RUN pip3 --version
 ---> Running in 1df781383970
pip 8.1.1 from /usr/lib/python3/dist-packages (python 3.5)
Removing intermediate container 1df781383970
 ---> ad30a1cd5323
Step 7/14 : COPY . /app
 ---> db6769b7ba80
Step 8/14 : WORKDIR /app
 ---> Running in c234276bf1f6
Removing intermediate container c234276bf1f6
 ---> face402e69b6
Step 9/14 : RUN pip3 install -r requirements.txt
 ---> Running in d89df8c75e5a
Collecting Flask==1.1.1 (from -r requirements.txt (line 1))
  Downloading https://files.pythonhosted.org/packages/9b/93/628509b8d5dc749656a9641f4caf13540e2cdec85276964ff8f43bbb1d3b/Flask-1.1.1-py2.py3-none-any.whl (94kB)
Collecting numpy==1.16.4 (from -r requirements.txt (line 2))
  Downloading https://files.pythonhosted.org/packages/bb/ef/d5a21cbc094d3f4d5b5336494dbcc9550b70c766a8345513c7c24ed18418/numpy-1.16.4-cp35-cp35m-manylinux1_x86_64.whl (17.2MB)
Collecting Pillow==6.1.0 (from -r requirements.txt (line 3))
  Downloading https://files.pythonhosted.org/packages/d6/98/0d360dbc087933679398d73187a503533ec0547ba4ffd2115365605559cc/Pillow-6.1.0-cp35-cp35m-manylinux1_x86_64.whl (2.1MB)
Collecting Werkzeug>=0.15 (from Flask==1.1.1->-r requirements.txt (line 1))
  Downloading https://files.pythonhosted.org/packages/d1/ab/d3bed6b92042622d24decc7aadc8877badf18aeca1571045840ad4956d3f/Werkzeug-0.15.5-py2.py3-none-any.whl (328kB)
Collecting itsdangerous>=0.24 (from Flask==1.1.1->-r requirements.txt (line 1))
  Downloading https://files.pythonhosted.org/packages/76/ae/44b03b253d6fade317f32c24d100b3b35c2239807046a4c953c7b89fa49e/itsdangerous-1.1.0-py2.py3-none-any.whl
Collecting click>=5.1 (from Flask==1.1.1->-r requirements.txt (line 1))
  Downloading https://files.pythonhosted.org/packages/fa/37/45185cb5abbc30d7257104c434fe0b07e5a195a6847506c074527aa599ec/Click-7.0-py2.py3-none-any.whl (81kB)
Collecting Jinja2>=2.10.1 (from Flask==1.1.1->-r requirements.txt (line 1))
  Downloading https://files.pythonhosted.org/packages/1d/e7/fd8b501e7a6dfe492a433deb7b9d833d39ca74916fa8bc63dd1a4947a671/Jinja2-2.10.1-py2.py3-none-any.whl (124kB)
Collecting MarkupSafe>=0.23 (from Jinja2>=2.10.1->Flask==1.1.1->-r requirements.txt (line 1))
  Downloading https://files.pythonhosted.org/packages/6e/57/d40124076756c19ff2269678de7ae25a14ebbb3f6314eb5ce9477f191350/MarkupSafe-1.1.1-cp35-cp35m-manylinux1_x86_64.whl
Installing collected packages: Werkzeug, itsdangerous, click, MarkupSafe, Jinja2, Flask, numpy, Pillow
Successfully installed Flask-1.1.1 Jinja2-2.10.1 MarkupSafe-1.1.1 Pillow-6.1.0 Werkzeug-0.15.5 click-7.0 itsdangerous-1.1.0 numpy-1.16.4
You are using pip version 8.1.1, however version 19.2.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
Removing intermediate container d89df8c75e5a
 ---> 95766b1e174e
Step 10/14 : RUN pip3 install flask
 ---> Running in 97e806168780
Requirement already satisfied (use --upgrade to upgrade): flask in /usr/local/lib/python3.5/dist-packages
Requirement already satisfied (use --upgrade to upgrade): itsdangerous>=0.24 in /usr/local/lib/python3.5/dist-packages (from flask)
Requirement already satisfied (use --upgrade to upgrade): Jinja2>=2.10.1 in /usr/local/lib/python3.5/dist-packages (from flask)
Requirement already satisfied (use --upgrade to upgrade): Werkzeug>=0.15 in /usr/local/lib/python3.5/dist-packages (from flask)
Requirement already satisfied (use --upgrade to upgrade): click>=5.1 in /usr/local/lib/python3.5/dist-packages (from flask)
Requirement already satisfied (use --upgrade to upgrade): MarkupSafe>=0.23 in /usr/local/lib/python3.5/dist-packages (from Jinja2>=2.10.1->flask)
You are using pip version 8.1.1, however version 19.2.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
Removing intermediate container 97e806168780
 ---> dd8d93e7b8bc
Step 11/14 : RUN which flask
 ---> Running in 0ac4678d5ecd
/usr/local/bin/flask
Removing intermediate container 0ac4678d5ecd
 ---> e9325cc606ec
Step 12/14 : RUN ls -alh
 ---> Running in e249ecafd7fa
total 1.8M
drwxr-xr-x 6 root root  4.0K Aug  4 14:29 .
drwxr-xr-x 1 root root  4.0K Aug  4 14:30 ..
-rw-r--r-- 1 root root   11K Aug  2 11:15 .DS_Store
drwxr-xr-x 5 root root  4.0K Jul 28 11:45 .git
-rw-r--r-- 1 root root    18 Aug  2 13:52 .gitignore
-rw-r--r-- 1 root root   878 Aug  4 14:27 Dockerfile
-rw-r--r-- 1 root root 1004K Jul 24 12:49 Image Classifier Project.html
-rw-r--r-- 1 root root  690K Jul 24 12:50 Image Classifier Project.ipynb
-rw-r--r-- 1 root root  1.1K Feb  6  2018 LICENSE
-rw-r--r-- 1 root root   686 Aug  2 14:04 README.md
drwxr-xr-x 2 root root  4.0K Aug  4 13:05 __pycache__
-rw-r--r-- 1 root root  1018 Aug  4 14:12 api.py
drwxr-xr-x 2 root root  4.0K Jul 20 12:32 assets
-rw-r--r-- 1 root root  2.2K Feb  6  2018 cat_to_name.json
drwxr-xr-x 2 root root  4.0K Jul 24 12:06 checkpoints
-rw-r--r-- 1 root root   245 Aug  2 21:48 environment.yml
-rw-r--r-- 1 root root   921 Aug  4 09:11 environment0.yml
-rw-r--r-- 1 root root  8.6K Aug  4 13:02 flower_classifier.py
-rw-r--r-- 1 root root  1.1K Aug  2 19:17 predict.py
-rw-r--r-- 1 root root    41 Aug  4 12:54 requirements.txt
-rw-r--r-- 1 root root  1.6K Aug  2 18:58 train.py
Removing intermediate container e249ecafd7fa
 ---> dfe9737330ac
Step 13/14 : ENTRYPOINT ["python3"]
 ---> Running in 57782c4a0d03
Removing intermediate container 57782c4a0d03
 ---> 7e6b0d1d5656
Step 14/14 : CMD ["api.py"]
 ---> Running in 8400de10dc2d
Removing intermediate container 8400de10dc2d
 ---> 33733bebf60d
Successfully built 33733bebf60d
Successfully tagged flower-image-classifier:latest

运行容器时，出现以下错误：

$ docker run -p 5000:5000 flower-image-classifier
Traceback (most recent call last):
  File "api.py", line 1, in <module>
    from flask import Flask, request, jsonify
ModuleNotFoundError: No module named 'flask'

我对Docker / Python专家的问题是： 如果pip根据日志清楚地安装了flask怎么可能找不到flask ？

---

请注意，就像这个问题一样，我一开始也尝试从continuumio/miniconda3映像开始： Docker Flask ModuleNotFoundError：没有名为“ flask”的模块

我创建了这个environment.yml ：

name: fic
channels:
  - pytorch
  - defaults
dependencies:
  - flask=1.1.1
  - numpy=1.16.4
  - numpy-base=1.16.4
  - pillow=6.1.0
  - python==3.6.9
  - pytorch=1.1.0
  - torchvision=0.3.0
  - pip:
    - pip==19.2.1
prefix: //anaconda3/envs/fic

然后，我对Dockerfile进行了一些修改，以从该映像扩展，并运行它以使用Conda安装依赖项：

RUN echo "source activate $(head -1 ./environment.yml | cut -d' ' -f2)" > ~/.bashrc
ENV PATH /opt/conda/envs/$(head -1 ./environment.yml | cut -d' ' -f2)/bin:$PATH

不幸的是，每次我构建Docker映像时，它都会下载并提取所有内容，这需要一段时间，并且下载通常会随机失败： CondaError: Downloaded bytes did not match Content-Length 。

当它最终成功构建时，我仍然为Flask遇到了相同的ModuleNotFoundError 。

怎么了 谢谢阅读

Answer 1

您只需指定正确的Python版本，因此只需将入口点更改为：

ENTRYPOINT ["python3.5"]