Wait until the pod it's running before getting information about it

controllers/nginx/nginx.tmpl

@@ -196,6 +196,18 @@ http {
             proxy_pass http://{{ $location.Upstream.Name }};
         }
         {{ end }}
+
+        {{ if eq $server.Name "_" }}
+        # this is required to avoid error if nginx is being monitored
+        # with an external software (like sysdig)
+        location /nginx_status {
+            allow 127.0.0.1;
+            deny all;
+
+            access_log off;
+            stub_status on;
+        }
+        {{ end }}
         {{ template "CUSTOM_ERRORS" $cfg }}
     }
     {{ end }}

controllers/nginx/utils.go

@@ -25,6 +25,7 @@ import (
 	"github.com/golang/glog"
 
 	"k8s.io/kubernetes/pkg/api"
+	apierrs "k8s.io/kubernetes/pkg/api/errors"
 	"k8s.io/kubernetes/pkg/client/cache"
 	"k8s.io/kubernetes/pkg/client/unversioned"
 	"k8s.io/kubernetes/pkg/util/wait"
@@ -100,7 +101,6 @@ func NewTaskQueue(syncFn func(string)) *taskQueue {
 // controller or daemonset (namespace and name).
 // This is required to watch for changes in annotations or configuration (ConfigMap)
 func getLBDetails(kubeClient *unversioned.Client) (*lbInfo, error) {
-	podIP := os.Getenv("POD_IP")
 	podName := os.Getenv("POD_NAME")
 	podNs := os.Getenv("POD_NAMESPACE")
 
@@ -109,6 +109,15 @@ func getLBDetails(kubeClient *unversioned.Client) (*lbInfo, error) {
 		return nil, fmt.Errorf("Unable to get POD information")
 	}
 
+	if pod.Status.Phase != api.PodRunning {
+		// we wait up to 30 seconds until the pod is running and
+		// it is possible to get the IP and name of the node
+		err := waitForPodRunning(kubeClient, podNs, podName, time.Millisecond*200, time.Second*30)
+		if err != nil {
+			return nil, err
+		}
+	}
+
 	node, err := kubeClient.Nodes().Get(pod.Spec.NodeName)
 	if err != nil {
 		return nil, err
@@ -128,6 +137,8 @@ func getLBDetails(kubeClient *unversioned.Client) (*lbInfo, error) {
 		}
 	}
 
+	podIP := os.Getenv("POD_IP")
+
 	return &lbInfo{
 		PodIP:        podIP,
 		Podname:      podName,
@@ -195,3 +206,37 @@ func parseNsName(input string) (string, string, error) {
 
 	return nsName[0], nsName[1], nil
 }
+
+func waitForPodRunning(kubeClient *unversioned.Client, ns, podName string, interval, timeout time.Duration) error {
+	condition := func(pod *api.Pod) (bool, error) {
+		if pod.Status.Phase == api.PodRunning {
+			return true, nil
+		}
+		return false, nil
+	}
+
+	return waitForPodCondition(kubeClient, ns, podName, condition, interval, timeout)
+}
+
+// waitForPodCondition waits for a pod in state defined by a condition (func)
+func waitForPodCondition(kubeClient *unversioned.Client, ns, podName string, condition func(pod *api.Pod) (bool, error),
+	interval, timeout time.Duration) error {
+	return wait.PollImmediate(interval, timeout, func() (bool, error) {
+		pod, err := kubeClient.Pods(ns).Get(podName)
+		if err != nil {
+			if apierrs.IsNotFound(err) {
+				return false, nil
+			}
+		}
+
+		done, err := condition(pod)
+		if err != nil {
+			return false, err
+		}
+		if done {
+			return true, nil
+		}
+
+		return false, nil
+	})
+}