Add Dockerfile and instructions

Dockerfile

@@ -0,0 +1,11 @@
+FROM docker.io/library/node:9.2
+
+ADD . /pegaswitch
+WORKDIR /pegaswitch
+
+RUN npm install
+RUN npm install pty.js
+
+EXPOSE 53 53/udp 80 8100
+
+CMD node start.js --ip $IP_ADDR

README.md

@@ -28,6 +28,23 @@ Usage
 
 It should no longer be necessary to run `usefulscripts/SetupNew.js`, since PegaSwitch will now do it automatically.
 
+## Through Docker
+### Building
+The container image is based on the official `nodejs:9.2` image.
+To build the docker container image simply run:
+
+`docker build -t reswitched/pegaswitch .`
+
+
+### Running
+To run the docker container container first you have to figure out your
+local network IP address.
+
+1. Run `ip a`
+2. Run `docker run -ti -p 53:53/udp -p 53:53 -p 80:80 -p 8100:8100 --env TERM --env IP_ADDR={your IP address from the prior command} reswitched/pegaswitch`
+
+If you fail to set the `IP_ADDR` variable the container will not start.
+
 Documentation
 =============