Docker [railsエラー]

Question

dockerの環境構築をしています。
しかし、下記のエラーにハマってなかなか解決できていない状況です。
railsの設定で何かしらエラーが起きている原因た管理者権限が付与されていない？のが原因だと思いますが、原因がわかる方いますでしょうか？

bundler: failed to load command: rails (/usr/local/bundle/bin/rails)
web_1  | Errno::EPERM: Operation not permitted @ rb_sysopen - /aaaa/Gemfile
web_1  |   /usr/local/lib/ruby/gems/2.5.0/gems/bundler-1.16.6/lib/bundler/dsl.rb:528:in `read'
web_1  |   /usr/local/lib/ruby/gems/2.5.0/gems/bundler-1.16.6/lib/bundler/dsl.rb:528:in `contents'
web_1  |   /usr/local/lib/ruby/gems/2.5.0/gems/bundler-1.16.6/lib/bundler/dsl.rb:558:in `to_s'
web_1  |   /usr/local/lib/ruby/gems/2.5.0/gems/bundler-1.16.6/lib/bundler/setup.rb:12:in `message'
web_1  |   /usr/local/lib/ruby/gems/2.5.0/gems/bundler-1.16.6/lib/bundler/setup.rb:12:in `rescue in <top (required)>'
web_1  |   /usr/local/lib/ruby/gems/2.5.0/gems/bundler-1.16.6/lib/bundler/setup.rb:9:in `<top (required)>'
web_1  |   /usr/local/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:59:in `require'
web_1  |   /usr/local/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:59:in `require'

FROM ruby:2.5.1
RUN apt-get update && apt-get install -y \
    build-essential \
    nodejs
WORKDIR /aaaa
COPY Gemfile Gemfile.lock /aaaa/
RUN gem install bundler && bundle install 
COPY . /aaaa

version: '3'

volumes:
  mysql-data:

services:
  db:
    image: mysql:5.7
    environment:
      MYSQL_USER: root
    cap_add:
      - SYS_ADMIN
    security_opt:
      - seccomp:unconfined
    ports:
      - "4306:3306"
    volumes:
      - ./db/mysql/volumes:/var/lib/mysql

  web:
    build: .
    command: bash -c "rm -f tmp/pids/server.pid && bundle exec rails s -p 3000 -b '0.0.0.0'"
    ports:
      - '3000:3000'
    volumes:
      - '.:/aaaa'
    tty: true           
    stdin_open: true
    depends_on:
      - db

# MySQL. Versions 5.1.10 and up are supported.
#
# Install the MySQL driver
#   gem install mysql2
#
# Ensure the MySQL gem is defined in your Gemfile
#   gem 'mysql2'
#
# And be sure to use new-style password hashing:
#   https://dev.mysql.com/doc/refman/5.7/en/password-hashing.html
#
default: &default
  adapter: mysql2
  encoding: utf8
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  username: root
  password: 
  host: db
  # socket: /tmp/mysql.sock

development:
  <<: *default
  database: KStargram_development

# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
  <<: *default
  database: KStargram_test

# As with config/secrets.yml, you never want to store sensitive information,
# like your database password, in your source code. If your source code is
# ever seen by anyone, they now have access to your database.
#
# Instead, provide the password as a unix environment variable when you boot
# the app. Read http://guides.rubyonrails.org/configuring.html#configuring-a-database
# for a full rundown on how to provide these environment variables in a
# production deployment.
#
# On Heroku and other platform providers, you may have a full connection URL
# available as an environment variable. For example:
#
#   DATABASE_URL="mysql2://myuser:mypass@localhost/somedatabase"
#
# You can use this database configuration with:
#
#   production:
#     url: <%= ENV['DATABASE_URL'] %>
#
production:
  # <<: *default
  adapter: postgresql
  encoding: unicode
  database: aaaa_production
  username: aaaa
  password: <%= ENV['AAAA_DATABASE_PASSWORD'] %>
  pool: 5

Answer 1

推測なのですが、
WORKDIR /aaaaの一行の前に
RUN mkdir /aaaaが抜けてるように見えます。

WORKDIRはDocker上で作業のディレクトリを指定する命令ですが、
そもそもその作業をするディレクトリが作られていないのでは？と考えました。

見当違いでしたら申し訳ないです；；