Hacky Zuul filter which validates the request endpoint, sets host depending on API version and shows how to override static HttpServletRequest paths using an HttpServletRequestWrapper (routing really should be done in separate route filter)

Zuul-SPINE.groovy

package scripts.preProcess

import com.netflix.zuul.ZuulFilter
import com.netflix.zuul.context.Debug
import com.netflix.zuul.context.RequestContext
import org.apache.commons.lang.StringUtils
import org.apache.http.MethodNotSupportedException
import org.codehaus.groovy.util.StringUtil

import javax.servlet.http.HttpServletRequest
import javax.servlet.http.HttpServletRequestWrapper
import java.util.regex.Pattern

/**
 * Created by jesse on 20/03/2014.
 */

class SpineApiFilter extends ZuulFilter{

    def apis = new HashSet(['bonus','player'])
    private String api

    @Override
    String filterType() {
        return 'pre'
    }

    @Override
    int filterOrder() {
        return 1
    }

    @Override
    boolean shouldFilter() {
        return true
    }

    @Override
    Object run() {
        try{
            String[] uriBits = RequestContext.getCurrentContext().getRequest().getRequestURI().split("/")
            api = uriBits.getAt(1)

            Debug.addRequestDebug("VALIDATING:: " + uriBits.toString())
        }catch (IndexOutOfBoundsException e){
            Debug.addRequestDebug("SPINE API:: No Endpoint Specified")
            return null
        }

        if(apis.contains(api)){
            Debug.addRequestDebug("SPINE API:: Valid API Requested")
        }else{
            Debug.addRequestDebug("SPINE API:: Invalid API Requested")
            RequestContext.getCurrentContext().setRouteHost(new URL("http://www.google.co.uk/404"))
            return null
        }

        Debug.addRequestDebug("API REQUEST:: URI: " + RequestContext.getCurrentContext().getRequest().getRequestURI())
        Debug.addRequestDebug("API REQUEST:: Path: " + RequestContext.getCurrentContext().getRequest().getPathInfo())

        try{
            "$api"(RequestContext.getCurrentContext().getRequest())
        }catch (Exception e){
            Debug.addRequestDebug("couldn't find dynamic routing method for " + api)
        }
        return null
    }

    void bonus(HttpServletRequest req) {

        def path = req.getPathInfo().split("/")
        Debug.addRequestDebug("BONUS API REQUEST:: Path - " + path.toString())
        if(path[1]=="v3"){
            RequestContext.getCurrentContext().setRouteHost(new URL("https://a1-qa01-btv3.cloudapp.net"))
            Debug.addRequestDebug("BONUS API REQUEST:: API Version 3 - Changing Origin Route")
        }else if(path[1]=="v2"){
            RequestContext.getCurrentContext().setRouteHost(new URL("https://a1-qa01-btv2.cloudapp.net"))
            Debug.addRequestDebug("BONUS API REQUEST:: API Version 2 - Changing Origin Route")
        }else{
            Debug.addRequestDebug("BONUS API REQUEST:: API Version Unknown")
        }

        HttpServletRequestWrapper wrappedRequest = new HttpServletRequestWrapper(req){
            private HttpServletRequest request = req;

            public String getPathInfo(){
                return new String(
                        request.getPathInfo().replaceFirst(new Pattern(/\/bonus\/v\d\//,0),'/help')
                )
            }
            public String getRequestURI(){
                return new String(
                        request.getRequestURI().replaceFirst(new Pattern(/\/bonus\/v\d\//,0),'/help')
                )
            }
            public StringBuffer getRequestURL(){
                return new StringBuffer(
                        request.getRequestURL().toString().replaceFirst(new Pattern(/\/bonus\/v\d\//,0),'/help')
                )
            }
        }
        RequestContext.getCurrentContext().setRequest(wrappedRequest)
    }

    void player(HttpServletRequest req){

        RequestContext.getCurrentContext().setRouteHost(new URL("https://qa01-sgp.bedegaming.net:18201"))

        HttpServletRequestWrapper wrappedRequest = new HttpServletRequestWrapper(req){
            private HttpServletRequest request = req;

            public String getPathInfo(){
                return new String(
                        request.getPathInfo().replaceFirst('/player','/Player/help')
                )
            }
            public String getRequestURI(){
                return new String(
                        request.getRequestURI().replaceFirst('/player','/Player/help')
                )
            }
            public StringBuffer getRequestURL(){
                return new StringBuffer(
                        request.getRequestURL().toString().replaceFirst('/player','/Player/help')
                )
            }
        }
        RequestContext.getCurrentContext().setRequest(wrappedRequest)
    }

}