Access error on master.key

[Samuel Grave Silva]

Hello Everyone!
I'm doing the Agile Web Development with Rails 7 book, and I'm in the part they deploy a docker image with passenger.
I followed the instructions at the book, but I'm receiving the following error:

depot-web-1 | [ E 2023-11-07 13:05:21.1378 48/Tr age/Cor/App/Implementation.cpp:221 ]: Could not spawn process for application /home/app/depot: The application encountered the following error: Permission denied @ rb_sysopen - /home/app/depot/config/master.key (Errno::EACCES)

Tried to change the owner of the file, without success too :(

root@94418ca40230:/home/app/depot/config# chown -R app: master.key
chown: changing ownership of 'master.key': Read-only file system

Here's my docker-compose file:

version: "3.8"

services:

db:

image: postgres:14

volumes:

- pgdata:/var/lib/postgresql/data

environment:

POSTGRES_PASSWORD: password

web:

build: .

volumes:

- ./log:/home/app/depot/log

secrets:

- source: master_key

target: /home/app/depot/config/master.key

ports:

- "8001:80"

depends_on:

- db

secrets:

master_key:

file: ./config/master.key

volumes:

pgdata:

and here my Dockerfile:

FROM phusion/passenger-full:latest

RUN rm /etc/nginx/sites-enabled/default

RUN rm -f /etc/service/nginx/down

RUN rm -f /etc/service/redis/down

ADD config/nginx.conf /etc/nginx/sites-enabled/depot.conf

USER app

RUN mkdir /home/app/depot

WORKDIR /home/app/depot

ENV RAILS_ENV=production

ENV BUNDLE_WITHOUT="development test"

RUN bash -lc 'rvm --default use ruby-3.2.2'

COPY --chown=app:app Gemfile Gemfile.lock .

RUN bundle install

COPY --chown=app:app . .

RUN SECRET_KEY_BASE=`bin/rails secret` \

bin/rails assets:precompile

USER root

CMD ["/sbin/my_init"]

I'm using Ruby 3.2.2 and Rails 7.1

Thanks for help :)