python - Docker Build 找不到 pip

Question

尝试关注一些[ 1 ][ 2 ] 通过 AWS am 的简单 Docker 教程并收到以下错误:

> docker build -t my-app-image .                                         
Sending build context to Docker daemon 94.49 MB
Step 1 : FROM amazon/aws-eb-python:3.4.2-onbuild-3.5.1
# Executing 2 build triggers...
Step 1 : ADD . /var/app
 ---> Using cache
Step 1 : RUN if [ -f /var/app/requirements.txt ]; then /var/app/bin/pip install -r /var/app/requirements.txt; fi
 ---> Running in d48860787e63
/bin/sh: 1: /var/app/bin/pip: not found
The command '/bin/sh -c if [ -f /var/app/requirements.txt ]; then /var/app/bin/pip install -r /var/app/requirements.txt; fi' returned a non-zero code: 127

Dockerfile:

# For Python 3.4
FROM amazon/aws-eb-python:3.4.2-onbuild-3.5.1

哪个 pip 返回以下内容:

> which pip                                                             
./bin/pip

相关文件结构:

.
├── Dockerfile
├── bin
│   ├── activate
│   ├── pip
│   ├── pip3
│   ├── pip3.5
│   ├── python -> python3
│   ├── python-config
│   ├── python3
│   ├── python3.5 -> python3
│   .
.

再说一次，Docker 在所有方面都是菜鸟，所以我不确定要采取哪些故障排除步骤。请让我知道我可以提供哪些其他有用的信息。

Answer 1

这里有些奇怪。为什么你的 Dockerfile 旁边有 virtualenv 内容？ The image you are building from在/var/app 上为您创建 virtualenv(在容器内，是吗？)。我相信 ONBUILD 命令会复制它(或其中的一部分)并破坏进程的其余部分，使/var/app/bin/pip 无法运行。

FROM       python:3.4.2 <-- this is the base image, on top of which the following command will be applied

WORKDIR    /var/app <-- this is the working dir (a la 'cd /var/app')

RUN        pip3 install virtualenv <-- using pip3 (installed using base image I presume) to install the virtualenv package
RUN        virtualenv /var/app <-- creating a virtual env on /var/app
RUN        /var/app/bin/pip install --download-cache /src uwsgi <-- using the recently install virtualenv pip to install uwsgi

...

ONBUILD    ADD . /var/app <-- add the contents of the directory where the Dockerfile is built from, I think this is where the corruption happen 
ONBUILD    RUN if [ -f /var/app/requirements.txt ]; then /var/app/bin/pip install -r /var/app/requirements.txt; fi <-- /var/app/bin/pip has beed corrupted

您不应该关心主机上是否有外部可用的/var/app。您只需要(基于 Dockerbuild 文件)在主机上有可用的“requirements.txt”，复制到容器中(或者不复制，如果没有，它将跳过)。