How to run a command before CMD in dockerfile?-CodePudding

I have a dockerfile looking like this :

FROM python:3.10-slim
WORKDIR /app
COPY requirements.txt .
RUN pip install -r requirements.txt
ADD . /app
CMD python script.py

(requirements.txt contains "black").

I would like to run black on script.py before running script.py, so that script.py get formatted correctly when the container starts. I dont understand how I am supposed to do this, knowing that I cant use CMD twice . I feel like I'm missing how docker is supposed to be used.

CodePudding user response：

Additionally try not to use ADD, COPY is almost always better, use ADD only if you are copying files from link or copying compressed files.

CodePudding user response：

Solution is here. In my case, it is :

Dockerfile:

FROM python:3.10-slim
WORKDIR /app
COPY requirements.txt .
RUN pip install -r requirements.txt
ADD . /app

ADD start.sh /
RUN chmod  x /start.sh

CMD ["/start.sh"]

start.sh:

#!/bin/bash

black script.py
python script.py