X-Forwarded ZuulFilter

gistfile1.txt

import org.eclipse.jetty.http.HttpHeader;
import org.springframework.cloud.netflix.zuul.filters.ProxyRequestHelper;
import org.springframework.stereotype.Component;

import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;

@Component
public class XForwardedHeadersPreFilter extends ZuulFilter
{
    private static final String XFHOST_HEADER = HttpHeader.X_FORWARDED_HOST.toString();
    private static final String XFFOR_HEADER = HttpHeader.X_FORWARDED_FOR.toString();
    private static final String XFPROTO_HEADER = HttpHeader.X_FORWARDED_PROTO.toString();
    private static final String XFPORT_HEADER = "X-Forwarded-Port";

    private static final String[] XF_HEADERS = { XFHOST_HEADER, XFFOR_HEADER, XFPROTO_HEADER, XFPORT_HEADER };

    private ProxyRequestHelper helper = new ProxyRequestHelper();

    @Override
    public int filterOrder()
    {
        return 4;
    }

    @Override
    public String filterType()
    {
        return "pre";
    }

    @Override
    public boolean shouldFilter()
    {
        return true;
    }

    @Override
    public Object run()
    {
        RequestContext ctx = RequestContext.getCurrentContext();
        int port = ctx.getRequest().getServerPort();
        String clientIp = ctx.getRequest().getRemoteAddr();
        String scheme = ctx.getRequest().getScheme();

        ctx.addZuulRequestHeader(XFHOST_HEADER, getHostHeaderValue(ctx, scheme, port));
        ctx.addZuulRequestHeader(XFFOR_HEADER, clientIp);
        ctx.addZuulRequestHeader(XFPROTO_HEADER, scheme);
        ctx.addZuulRequestHeader(XFPORT_HEADER, String.valueOf(port));

        //This will make sure that the original headers are not passed down the chain
        helper.addIgnoredHeaders(XF_HEADERS);

        return null;
    }

    private String getHostHeaderValue(RequestContext ctx,
                                      String scheme,
                                      int port)
    {
        String host = ctx.getRequest().getServerName();
        if ((scheme.equals("http") && port != 80) || (scheme.equals("https") && port != 443)) {
            host = String.format("%s:%d", host, port);
        }
        return host;
    }
}