Change directory in docker alpine failing

Question

Trying to build a dockerfile with alpine image and install set of directories. Here is the script below. It works fine until mkdir but does not change to /opt to download the git code.

The git code gets downloaded only to /src. Not sure whey the cd /opt command does not work.

FROM alpine
ADD . /src
WORKDIR /src
RUN apk update
RUN apk add git
RUN mkdir /opt
RUN cd /opt  && git clone --recursive https://github.com/Azure/azure-iot-sdk-python.git 
RUN ls -al 
RUN cd azure-iot-sdk-python && ls -al build_all/linux

Answer 1

The current working directory is reset for every RUN to the value of the last WORKDIR .

So, because of that, this line RUN cd azure-iot-sdk-python && ls -al build_all/linux is doing it from here /src , and your cloned repo is in opt .

So both of this will work:

RUN cd /opt/azure-iot-sdk-python && ls -al build_all/linux

and:

WORKDIR /opt
RUN cd azure-iot-sdk-python && ls -al build_all/linux

Answer 2

Robert是对的，您可以按照Dockerfile最佳实践来避免此问题，并且只有一个RUN，请参阅https://docs.docker.com/engine/userguide/eng-image/dockerfile_best-practices/