SSL Endpoint with Heroku and 303 - rest

Question

I have created an SSL Endpoint with heroku. I have a test environment and a live environment. I have a REST call that generates a 303. Since Heroku handles the SSL in it's router, I'm not sure how I can detect if my SEE OTHER URL should create an HTTP or HTTPS based URI. Here's some sample code:
#GET
#Path( "/job/{jobId}" )
public Response getCallStatus( #PathParam( "jobId" ) Long jobId, #Context UriInfo uriInfo ) throws Exception {
if ( !jobService.isDone( jobId ) )
return build( Response.ok( POLLING_FREQUENCY ) );
URI jobLocation = uriInfo.getAbsolutePathBuilder().path( "result" ).build();
return build( Response.seeOther( jobLocation ) );
}
Because my server isn't handling the SSL (heroku is) the absolute path for the REST call will use HTTP instead of HTTPS. If I hard code HTTPS I will break my unit tests or other environment that do not require the HTTPS protocol.
Any thoughts? Or am I misunderstanding how heroku is doing this?

Answer 1

Okay, so here's the answer. Heroku does NOT forward the request as HTTPS. Because of this you need to look into the x-fowarded-proto header to decide what the 303 location is that you should send back to your client. The above code sample would change to something like this:
#GET
#Path( "/job/{jobId}" )
public Response getCallStatus( #PathParam( "jobId" ) Long jobId, #Context UriInfo uriInfo, #Context HttpHeaders headers ) throws Exception {
if ( !jobService.isDone( jobId ) )
return build( Response.ok( POLLING_FREQUENCY ) );
UriBuilder builder = uriInfo.getAbsolutePathBuilder().path( "result" );
String scheme = headers.getHeaderString( "x-forwarded-proto" );
if ( scheme != null )
builder.scheme( scheme );
return build( Response.seeOther( builder.build() ) );
}
That's basically it.
But a better way to handle it that would not require ANY changes in the coded REST METHOD would be to add a container request filter like this:
#PreMatching
public class HerokuContainerRequestFilter implements ContainerRequestFilter {
#Override
public void filter( ContainerRequestContext ctx ) throws IOException {
List<String> schemes = ctx.getHeaders().get( "x-forwarded-proto" );
if ( schemes != null && !schemes.isEmpty() ) {
String scheme = schemes.get( 0 );
UriBuilder builder = ctx.getUriInfo().getRequestUriBuilder();
ctx.setRequestUri( builder.scheme( scheme ).build() );
}
}
}
Then you just register this filter with your RestConfig like this:
public class RestApplication extends ResourceConfig {
public RestApplication() {
packages( "com.myapp.rest.service" );
// along with any other providers, etc that you register
register( HerokuContainerRequestFilter.class );
}
}

Answer 2

While user1888440 answer is totally working I'd rather configure https forwarding at server level.
For example, if you are using an embedded jetty as you're heroku web server you could use jetty built-in org.eclipse.jetty.server.ForwardedRequestCustomizer :
Customize Requests for Proxy Forwarding.
This customizer looks at at HTTP request for headers that indicate it has been forwarded by one or more proxies. Specifically handled are:
X-Forwarded-Host
X-Forwarded-Server
X-Forwarded-For
X-Forwarded-Proto
If these headers are present, then the Request object is updated so that the proxy is not seen as the other end point of the connection on which the request came
So instead of starting your server with :
Server server = new Server(port);
You could use :
Server server = new Server();
HttpConfiguration httpConfiguration = new HttpConfiguration();
httpConfiguration.addCustomizer(new ForwardedRequestCustomizer());
ServerConnector serverConnector = new ServerConnector(server, new HttpConnectionFactory(httpConfiguration));
serverConnector.setPort(port);
server.addConnector(serverConnector);