Added minimal Docker setup (#347)

backend/Dockerfile

@@ -0,0 +1,4 @@
+FROM yiisoftware/yii2-php:7.2-apache
+
+# Create a symlink for apache (if `/var/www/html` is available)
+RUN rm -rf /var/www/html && ln -s /app/backend/web/ /var/www/html || true

docker-compose.yml

@@ -0,0 +1,38 @@
+version: '3.2'
+
+services:
+
+  frontend:
+    build: frontend
+    ports:
+      - 20080:80
+    volumes:
+      # Re-use local composer cache via host-volume
+      - ~/.composer-docker/cache:/root/.composer/cache:delegated
+      # Mount source-code for development
+      - ./:/app
+
+  backend:
+    build: backend
+    ports:
+      - 21080:80
+    volumes:
+      # Re-use local composer cache via host-volume
+      - ~/.composer-docker/cache:/root/.composer/cache:delegated
+      # Mount source-code for development
+      - ./:/app
+
+  mysql:
+    image: mysql:5.7
+    environment:
+      - MYSQL_ROOT_PASSWORD=verysecret
+      - MYSQL_DATABASE=yii2advanced
+      - MYSQL_USER=yii2advanced
+      - MYSQL_PASSWORD=secret
+
+  #pgsql:
+  #  image: postgres:9.5
+  #  environment:
+  #    - POSTGRES_DB=yii2advanced
+  #    - POSTGRES_USER=yii2advanced
+  #    - POSTGRES_PASSWORD=secret

docs/guide/start-installation.md

@@ -280,3 +280,41 @@ That's all. You just need to wait for completion! After that you can access proj
 * frontend: http://y2aa-frontend.test
 * backend: http://y2aa-backend.test
 
+
+### Installing using Docker
+
+Install the application dependencies
+
+    docker-compose run --rm backend composer install
+
+Initialize the application by running the `init` command within a container
+
+    docker-compose run --rm backend /app/init
+
+Add a database service like and adjust the components['db'] configuration in `common/config/main-local.php` accordingly.
+    
+        'dsn' => 'mysql:host=mysql;dbname=yii2advanced',
+        'username' => 'yii2advanced',
+        'password' => 'secret',
+
+> Docker networking creates a DNS entry for the host `mysql` available from your `backend` and `frontend` containers.
+
+> If you want to use another database, such a Postgres, uncomment the corresponding section in `docker-compose.yml` and update your database connection.
+
+>         'dsn' => 'pgsql:host=pgsql;dbname=yii2advanced',
+
+For more information about Docker setup please visit the [guide](http://www.yiiframework.com/doc-2.0/guide-index.html).
+
+Run the migrations
+
+    docker-compose run --rm backend yii migrate
+           
+Start the application
+
+    docker-compose up -d
+    
+Access it in your brower by opening
+
+- frontend: http://127.0.0.1:20080
+- backend: http://127.0.0.1:21080
+

frontend/Dockerfile

@@ -0,0 +1,4 @@
+FROM yiisoftware/yii2-php:7.2-apache
+
+# Create a symlink for apache (if `/var/www/html` is available)
+RUN rm -rf /var/www/html && ln -s /app/frontend/web/ /var/www/html || true