How to give folder permissions inside a docker container Folder

Question

I am creating a folder inside my Dockerfile and I want to give it a write permission. But I am getting permission denied error when I try to do it

FROM python:2.7 RUN pip install Flask==0.11.1  RUN useradd -ms /bin/bash admin USER admin COPY app /app WORKDIR /app RUN chmod 777 /app CMD ["python", "app.py"]  

My error is

PS C:\Users\Shivanand\Documents\Notes\Praneeth's work\Flask> docker build -t  shivanand3939/test . Sending build context to Docker daemon  209.9kB Step 1/8 : FROM python:2.7 ---> 8a90a66b719a Step 2/8 : RUN pip install Flask==0.11.1 ---> Using cache ---> 6dc114bd7cf1 Step 3/8 : RUN useradd -ms /bin/bash admin ---> Using cache ---> 1cfdb6eea7dc Step 4/8 : USER admin ---> Using cache ---> 27c5e8b09f15 Step 5/8 : COPY app /app ---> Using cache ---> 5d628573b24f Step 6/8 : WORKDIR /app ---> Using cache ---> 351e19a5a007 Step 7/8 : RUN chmod 777 /app ---> Running in aaad3c79e0f4 **chmod: changing permissions of ‘/app’: Operation not permitted The command '/bin/sh -c chmod 777 /app' returned a non-zero code: 1** 

How can I give write permissions to app folder inside my Docker container

Answer 1

I guess you are switching to user "admin" which doesn't have the ownership to change permissions on /app directory. Change the ownership using "root" user. Below Dockerfile worked for me -

FROM python:2.7 RUN pip install Flask==0.11.1  RUN useradd -ms /bin/bash admin COPY app /app WORKDIR /app RUN chown -R admin:admin /app RUN chmod 755 /app USER admin CMD ["python", "app.py"]  

PS - Try to get rid of "777" permission. I momentarily tried to do it in above Dockerfile.