Pipeline: Do not terminate the stream upon errors

Stream::for_each terminated the stream upon the first error. This
was causing feeds to not update if any one returned a non-200ish
result. To work around this, we create a succesfull result for
every entry regardless at the end.

While we are at it, aslo switch from FuturesOrdered stream
to FuturesUnordered. There is no reason to use Ordered, this was
a typo initially.

podcasts-data/src/pipeline.rs

@@ -1,7 +1,7 @@
 // FIXME:
 //! Docs.
 
-use futures::{lazy, prelude::*, future::ok, stream::FuturesOrdered};
+use futures::{lazy, prelude::*, future::ok, stream::FuturesUnordered};
 use tokio;
 
 use hyper::client::HttpConnector;
@@ -28,7 +28,7 @@ pub fn pipeline<'a, S>(
     client: HttpsClient,
 ) -> impl Future<Item = (), Error = ()> + 'a
 where
-    S: Stream<Item = Source, Error = DataError> + 'a,
+    S: Stream<Item = Source, Error = DataError> + Send + 'a,
 {
     sources
         .and_then(move |s| s.into_feed(client.clone()))
@@ -39,10 +39,16 @@ where
                 _ => error!("Error: {}", err),
             }
         })
-        .for_each(move |feed| {
+        .and_then(move |feed| {
             let fut = lazy(|| feed.index().map_err(|err| error!("Error: {}", err)));
-            tokio::spawn(fut)
+            tokio::spawn(fut);
+            Ok(())
         })
+        // For each terminates the stream at the first error so we make sure
+        // we pass good values regardless
+        .then(move |_| ok(()))
+        // Convert the stream into a Future to later execute as a tokio task
+        .for_each(move |_| ok(()))
 }
 
 /// Creates a tokio `reactor::Core`, and a `hyper::Client` and
@@ -55,7 +61,7 @@ where
     let client = Client::builder().build::<_, Body>(https);
 
     let foo = sources.into_iter().map(ok::<_, _>);
-    let stream = FuturesOrdered::from_iter(foo);
+    let stream = FuturesUnordered::from_iter(foo);
     let p = pipeline(stream, client);
     tokio::run(p);