update instruction for running docker in vagrant

README.md

@@ -23,7 +23,7 @@ Check out [Swagger-Spec](https://github.com/OAI/OpenAPI-Specification) for addit
     - [Building](#building)
     - [Docker](#docker)
       - [Build and run](#build-and-run-using-docker)
-      - [Build a Node.js server stub](#build-a-nodejs-server-stub)
+      - [Run docker in Vagrant](#run-docker-in-vagrant)
       - [Public Docker image](#public-docker-image)
     - [Homebrew](#homebrew)
   - Generators
@@ -104,19 +104,21 @@ mvn package
 
 ```
 git clone https://github.com/swagger-api/swagger-codegen
-
 cd swagger-codegen
-
 ./run-in-docker.sh mvn package
  ```
 
-#### Build a Node.js server stub
 
+
+#### Run Docker in Vagrant
+Prerequisite: install [Vagrant](https://www.vagrantup.com/downloads.html) and [VirtualBox](https://www.virtualbox.org/wiki/Downloads).
  ```
-./run-in-docker.sh generate \
-  -i http://petstore.swagger.io/v2/swagger.json \
-  -l nodejs \
-  -o samples/server/petstore/nodejs
+git clone git@github.com:wizardbyron/swagger-codegen.git
+cd swagger-codegen
+vagrant up
+vagrant ssh
+cd /vagrant
+sudo ./run-in-docker.sh mvn package
  ```
 
 #### Public Docker image