Fixed- You must use Bundler 2 or greater with this lockfile. RUN gem update --system

Author: x1wins

Diff for: Dockerfile

@@ -1,5 +1,4 @@
 FROM ruby:2.6.0
-
 RUN curl -sL https://deb.nodesource.com/setup_8.x | bash - && \
     curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | apt-key add - && \
     echo "deb https://dl.yarnpkg.com/debian/ stable main" | tee /etc/apt/sources.list.d/yarn.list && \
@@ -9,5 +8,15 @@ RUN curl -sL https://deb.nodesource.com/setup_8.x | bash - && \
 RUN mkdir /myapp
 WORKDIR /myapp
 COPY . /myapp
+RUN gem update --system
 RUN bundle install
 RUN yarn install --check-files
+
+# Add a script to be executed every time the container starts.
+COPY entrypoint.sh /usr/bin/
+RUN chmod +x /usr/bin/entrypoint.sh
+ENTRYPOINT ["entrypoint.sh"]
+EXPOSE 3000
+
+# Start the main process.
+CMD ["rails", "server", "-b", "0.0.0.0"]

Diff for: docker-compose.yml

@@ -3,7 +3,7 @@ services:
   db:
     image: postgres:10.10
     volumes:
-      - pgdata:/var/lib/postgresql/data
+      - ./tmp/db:/var/lib/postgresql/data
     ports:
       - "5433:5432"
   web:

Diff for: entrypoint.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+set -e
+
+# Remove a potentially pre-existing server.pid for Rails.
+rm -f /myapp/tmp/pids/server.pid
+
+# Then exec the container's main process (what's set as CMD in the Dockerfile).
+exec "$@"