Runtime logs (#1447)

* Runtime logs

* Slightly broken

* Pushing for diff

* Log trailing works locally

* LogsOptions

* Comments and streamcount support for local logs

* Adding kubernetes logs

* Fixing k8s logs

* K8s fixes

* StreamCount is now nuked

* PR comments

* PR comments again

* Fix typo

runtime/kubernetes/kubernetes.go

@@ -301,6 +301,53 @@ func (k *kubernetes) Init(opts ...runtime.Option) error {
 	return nil
 }
 
+func (k *kubernetes) Logs(s *runtime.Service, options ...runtime.LogsOption) (runtime.LogStream, error) {
+	klo := newLog(k.client, s.Name, options...)
+	stream, err := klo.Stream()
+	if err != nil {
+		return nil, err
+	}
+	// If requested, also read existing records and stream those too
+	if klo.options.Count > 0 {
+		go func() {
+			records, err := klo.Read()
+			if err != nil {
+				logger.Errorf("Failed to get logs for service '%v' from k8s: %v", err)
+				return
+			}
+			// @todo: this might actually not run before podLogStream starts
+			// and might cause out of order log retrieval at the receiving end.
+			// A better approach would probably to suppor this inside the `klog.Stream` method.
+			for _, record := range records {
+				stream.Chan() <- record
+			}
+		}()
+	}
+	return stream, nil
+}
+
+type kubeStream struct {
+	// the k8s log stream
+	stream chan runtime.LogRecord
+	// the stop chan
+	stop chan bool
+}
+
+func (k *kubeStream) Chan() chan runtime.LogRecord {
+	return k.stream
+}
+
+func (k *kubeStream) Stop() error {
+	select {
+	case <-k.stop:
+		return nil
+	default:
+		close(k.stop)
+		close(k.stream)
+	}
+	return nil
+}
+
 // Creates a service
 func (k *kubernetes) Create(s *runtime.Service, opts ...runtime.CreateOption) error {
 	k.Lock()