Docker/docker-compose enhancements

The following enhancements have been made to docker/docker-compose

* Fixed bug when building the image.
* docker-compose up starts the server
* Scaffolding inside the container respect the ownership of the files
outside it
* Volumes are tagged as 'delegated' in order to improve performance for
mac/windoze users.
* bundler stores packages in a volume. This whay new packages can be
added without rebuilding the image:

```bash
docker-compose run app bundle install
```

.gitignore

@@ -33,3 +33,6 @@
 
 public/sitemap.xml
 public/system/
+
+# Ignore vim swap files
+*.swp

Dockerfile

@@ -1,8 +1,17 @@
-# # Select ubuntu as the base image
-FROM coreapps/ruby2.3
+FROM ruby:2.3.6
 
 # Install essential Linux packages
-RUN apt-get update -qq && apt-get install -y build-essential libpq-dev postgresql-client nodejs imagemagick
+RUN apt-get update -qq && apt-get install -y build-essential libpq-dev postgresql-client nodejs imagemagick sudo
+
+# Files created inside the container repect the ownership
+RUN adduser --shell /bin/bash --disabled-password --gecos "" consul \
+  && adduser consul sudo \
+  && echo '%sudo ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers
+
+RUN echo 'Defaults secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/local/bundle/bin"' > /etc/sudoers.d/secure_path
+RUN chmod 0440 /etc/sudoers.d/secure_path
+
+COPY scripts/entrypoint.sh /usr/local/bin/entrypoint.sh
 
 # Define where our application will live inside the image
 ENV RAILS_ROOT /var/www/consul

docker-compose.yml

@@ -1,5 +1,7 @@
-# service configuration for our database
-database:
+version: '3'
+services:
+  # service configuration for our database
+  database:
 
     # use the preferred version of the official Postgres image
     # see https://hub.docker.com/_/postgres/
@@ -9,18 +11,21 @@ database:
     volumes:
       - docker-example-postgres:/var/lib/postgresql/data
 
-# service configuration for our dockerized Rails app
-app:
+  # service configuration for our dockerized Rails app
+  app:
 
     # use the Dockerfile next to this file
     build: .
+    entrypoint: /usr/local/bin/entrypoint.sh
+    command: bundle exec rails s -p 3000 -b '0.0.0.0'
+    working_dir: /var/www/consul
 
     # rely on the RAILS_ENV value of the host machine
     # environment:
     #RAILS_ENV: $RAILS_ENV
 
     # makes the app container aware of the DB container
-  links:
+    depends_on:
       - database
 
     # expose the port we configured Unicorn to bind to
@@ -28,4 +33,8 @@ app:
       - "3000:3000"
     # map our application source code, in full, to the application root of our container
     volumes:
-    - .:/var/www/consul
+      - .:/var/www/consul:delegated
+      - bundle:/usr/local/bundle:delegated
+volumes:
+  docker-example-postgres: {}
+  bundle: {}

scripts/entrypoint.sh

@@ -0,0 +1,17 @@
+#!/bin/sh -x
+
+USER_UID=$(stat -c %u /var/www/consul/Gemfile)
+USER_GID=$(stat -c %g /var/www/consul/Gemfile)
+
+export USER_UID
+export USER_GID
+
+usermod -u "$USER_UID" consul 2> /dev/null
+groupmod -g "$USER_GID" consul 2> /dev/null
+usermod -g "$USER_GID" consul 2> /dev/null
+
+chown -R -h "$USER_UID" "$BUNDLE_PATH"
+chgrp -R -h "$USER_GID" "$BUNDLE_PATH"
+
+/usr/bin/sudo -EH -u consul "$@"
+