Docker Permission denied - ruby-on-rails

Question

I am trying to create an rails application through docker.
my docker-compose.yml file is :
mysql:
image: mysql:5.6.34
ports:
- "3006:3006"
volumes_from:
- dbdata
environment:
- MYSQL_ROOT_PASSWORD=root
- MYSQL_DATABASE=dev
dbdata:
image: tianon/true
volumes:
- /var/lib/mysql
app:
build: .
environment:
RAILS_ENV: development
ports:
- '3000:3000'
volumes_from:
- appdata
links:
- "mysql"
appdata:
image: tianon/true
volumes:
- ".:/dock_rails_1"
Dockerfile is :
FROM ruby:2.3.3
RUN apt-get update -qq && apt-get install -y build-essential libpq-dev nodejs mysql-client
RUN mkdir /dock_rails_1
WORKDIR /dock_rails_1
COPY Gemfile /dock_rails_1/Gemfile
COPY Gemfile.lock /dock_rails_1/Gemfile.lock
RUN bundle install
COPY . /dock_rails_1
My Gemfile is :
source 'https://rubygems.org'
gem 'rails', '5.0.0.1'
I have also created the empty Gemfile.lock.
After this run this command in my terminal:
docker-compose run app rails new . --force --database=mysql --skip-bundle
Every thing goes right. But I don't have edit acess to all the files created by docker.
When I am trying to edit the database.yml file created by docker it is telling permission denied.
Please help me why I am unable to edit my files.

Answer 1

Just making a few assumptions here, hope I'm right..
Probably, the user you use inside the container is root
and the file is created under root privileges.
Try to create and use a user with the same uid and gid as in your host machine.
you can find out your hosts uid/gid by running on your host:
cat /etc/passwd | grep $USER
change the containers user to hosts uid and gid in your docker file:
RUN usermod -u my_users_host_uid container_user
RUN groupmod -g my_users_host_gid container_user