check for container running before following logs

Signed-off-by: Ashish Amarnath <[email protected]>

pkg/client/logs.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"io"
 	"sync"
+	"time"
 
 	"github.com/pkg/errors"
 	"k8s.io/api/core/v1"
@@ -180,8 +181,35 @@ type logStreamer struct {
 	client             kubernetes.Interface
 }
 
+func (l *logStreamer) waitForContainerRunning(pod *v1.Pod) error {
+	backoffSeconds := 1 * time.Second
+	for {
+		for _, cs := range pod.Status.ContainerStatuses {
+			if cs.Name == l.container && cs.State.Running != nil {
+				return nil
+			}
+		}
+
+		//TODO: add a time out
+		time.Sleep(backoffSeconds)
+		backoffSeconds *= 2
+	}
+}
+
 // stream will open a connection to the pod's logs and push messages onto a fan-in channel.
 func (l *logStreamer) stream() {
+	if l.logOpts.Follow {
+		pod, err := l.client.CoreV1().Pods(l.ns).Get(l.pod, metav1.GetOptions{})
+		if err != nil {
+			l.errc <- errors.Wrapf(err, "failed to get pod [%s/%s]", l.ns, l.pod)
+			return
+		}
+		err = l.waitForContainerRunning(pod)
+		if err != nil {
+			l.errc <- errors.Wrapf(err, "failed to waiting for container [%v] in pod [%s/%s] to start running", l.container, l.ns, l.pod)
+			return
+		}
+	}
 	req := l.client.CoreV1().Pods(l.ns).GetLogs(l.pod, l.logOpts)
 	readCloser, err := req.Stream()
 	if err != nil {