docker python3 deployment fail-CodePudding

I deployed a docker container with this Dockerfile for my Django-rest-application:

FROM python:3
ENV PYTHONUNBUFFERED 1
RUN mkdir /app
WORKDIR /app
COPY requirements.txt /app/
COPY . /app/
RUN /usr/local/bin/python -m pip install --upgrade pip
RUN pip install -r requirements.txt

However, docker doesn't install python3 on my virtual machine, instead it install python2. Is there a way to make sure the docker install the correct python?

Thanks,

CodePudding user response：

Short answer

Python 3 is deployed within your image instance not in your virtual machine.

How to check python 3 is well used in your image :

Docker run

docker run --rm python:3 /bin/bash -c "python --version && pip --version"
# Python 3.10.0
# pip 21.2.4 from /usr/local/lib/python3.10/site-packages/pip (python 3.10)

Simple dockerfile

FROM python:3

ENV PYTHONUNBUFFERED 1

RUN python --version
RUN pip --version

Output, please see both python version and pip version

Sending build context to Docker daemon  41.47kB
Step 1/4 : FROM python:3
---> 618fff2bfc18
Step 2/4 : ENV PYTHONUNBUFFERED 1
---> Running in 421cfb4445ad
Removing intermediate container 421cfb4445ad
---> acc0f2c36571
Step 3/4 : RUN python --version
---> Running in 399632a39d32
Python 3.10.0
Removing intermediate container 399632a39d32
---> 3f78b14a2645
Step 4/4 : RUN pip --version
---> Running in 5b541e3ff5a0
pip 21.2.4 from /usr/local/lib/python3.10/site-packages/pip (python 3.10)

Your dockerfile

FROM python:3

ENV PYTHONUNBUFFERED 1

WORKDIR /app

COPY . .

RUN pip install --upgrade pip && pip install -r requirements.txt

How to use it with docker run
```
docker run <image id/name>
```

For more information :

docker run :https://docs.docker.com/engine/reference/commandline/run/
dockerfile : https://docs.docker.com/engine/reference/builder/

CodePudding user response：

If you want to check the version of Python inside your image you can do:

$ docker run -it <image_name_or_hash> bash

when you are 'inside', run

python --version