add dockerfile

README.org

@@ -87,6 +87,22 @@
     | =cloudName= | Name of the raincloud             | =str= | =raincloud=   | =bobsCloud=          |
     | =basePath=  | Base path of the raincloud        | =str= |               | =/var/lib/raincloud= |
 
+*** Docker
+
+    A self-contained =Dockerfile=, based on [[https://www.alpinelinux.org/][Alpine Linux]], is available in the repository.
+    You can use it to build a /raincloud/ image locally with the following command:
+
+    : $ docker build -t raincloud:latest -f Dockerfile
+
+    A container of the image exposes raincloud at port =8000= and uses the base directory =/var/www/raincloud=.
+    Use dockers =-p= and =-v= flag to map the port on your host and to mount a base directory:
+
+    : $ docker run -p <local_port>:8000 -v <path_to_local_base_directory>:/var/www/raincloud raincloud:latest
+
+    If you want to change the cloud name you can pass the =cloud_name= environment variable to the container:
+
+    : $ docker run -p <local_port>:8000 -v <path_to_local_base_directory>:/var/www/raincloud -e "cloud_name=podcloud" raincloud:latest
+
 ** Configuration
 
    /raincloud/ provides two configuration options which can be passed to =raincloud.create_app()=: