presto-main/src/main/java/io/prestosql/server/WebUiResource.java/WebUiResource/redirectIndexHtml
class WebUiResource:    @GET
    public Response redirectIndexHtml(
            @HeaderParam(X_FORWARDED_PROTO) String proto,
            @Context UriInfo uriInfo)
    {
        if (isNullOrEmpty(proto)) {
            proto = uriInfo.getRequestUri().getScheme();
        }

        return Response.status(TEMPORARY_REDIRECT)
                .location(uriInfo.getRequestUriBuilder().scheme(proto).path("/ui/").build())
                .build();
    }