How to add symbolic link or alias to dockerfile? - docker

Question

I have the following dockerfile:
FROM python:3.10-alpine
LABEL Name=my_app
WORKDIR /app
RUN addgroup --gid 1000 -S my_app && \
adduser --uid 1000 -D -S my_app -G my_app -s /sbin/nologin
COPY --chown=1000:1000 pyproject.toml README.rst src ./
RUN apk add --no-cache --virtual=.build-deps build-base libffi-dev curl openssl-dev && \
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y && \
source $HOME/.cargo/env && \
pip install --upgrade pip && pip install --no-cache-dir ./ && \
apk del .build-deps && \
rustup self uninstall -y
RUN chown -R 1000:1000 /app
USER my_app
It is working and I am capable to run inside of this container the following command: my_app run --checks all path_name. Because some reason I need to change my_app key phrase to my_app_2 key phrase. So I would able to run the following command: my_app_2 run --checks all path_name. I cannot change underling files outside of dockerfile because of some server configuration. What changes in dockerfile could I make?
I tried to add:
RUN ln -s /usr/local/bin/my_app /usr/local/bin/my_app_2
But getting an error during build prosses::
=> ERROR [7/7] RUN ln -s /usr/local/bin/my_app /usr/local/bin/my_app 0.3s
------
> [7/7] RUN ln -s /usr/local/bin/my_app /usr/local/bin/my_app_2:
#0 0.256 ln: /usr/local/bin/my_app_2: Permission denied
------
failed to solve: executor failed running [/bin/sh -c ln -s /usr/local/bin/my_app /usr/local/bin/my_app_2]: exit code: 1
Also I tried to swap my_app_2 and my_app:
RUN ln -s /usr/local/bin/my_app_2 /usr/local/bin/my_app
But getting another error during build prosses:
=> ERROR [7/7] RUN ln -s /usr/local/bin/my_app_2 /usr/local/bin/my_app 0.5s
------
> [7/7] RUN ln -s /usr/local/bin/my_app_2 /usr/local/bin/my_app:
#0 0.516 ln: /usr/local/bin/my_app: File exists
------
failed to solve: executor failed running [/bin/sh -c ln -s /usr/local/bin/my_app_2 /usr/local/bin/my_app]: exit code: 1
Third attempt. I added:
RUN echo "alias my_app_2='my_app'" >> ~/.bashrc
Built was successful but when I run
my_app_2 run --checks all my_path_here
I am getting:
sh: my_app_2: not found

Answer 1

Run the command while you are still root. Unprivileged users can't modify arbitrary files on the filesystem:
FROM python:3.10-alpine
LABEL Name=my_app
WORKDIR /app
RUN addgroup --gid 1000 -S my_app && \
adduser --uid 1000 -D -S my_app -G my_app -s /sbin/nologin
COPY --chown=1000:1000 pyproject.toml README.rst src ./
RUN apk add --no-cache --virtual=.build-deps build-base libffi-dev curl openssl-dev && \
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y && \
source $HOME/.cargo/env && \
pip install --upgrade pip && pip install --no-cache-dir ./ && \
apk del .build-deps && \
rustup self uninstall -y
# run other steps as root here
RUN ln -s /usr/local/bin/my_app /usr/local/bin/my_app_2
RUN chown -R 1000:1000 /app
USER my_app
# you are no longer root here