kubelet: record an event with a clear reason on host port conflict

Currently, kubelet silently ignores pods that caused host port conflict. This
commit surfaces the error by recording an event.

It also makes sure that kubelet iterates through the pods in the order of the
creation timestamp, which ensures that pods created later are ignored on
conflict.
This commit is contained in:
Yu-Ju Hong 2015-02-27 13:43:21 -08:00
parent d98b081cf8
commit 241df2d3be
3 changed files with 60 additions and 0 deletions

View File

@ -1378,15 +1378,35 @@ func updateBoundPods(changed []api.BoundPod, current []api.BoundPod) []api.Bound
return updated
}
type podsByCreationTime []api.BoundPod
func (s podsByCreationTime) Len() int {
return len(s)
}
func (s podsByCreationTime) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func (s podsByCreationTime) Less(i, j int) bool {
return s[i].CreationTimestamp.Before(s[j].CreationTimestamp)
}
// filterHostPortConflicts removes pods that conflict on Port.HostPort values
func filterHostPortConflicts(pods []api.BoundPod) []api.BoundPod {
filtered := []api.BoundPod{}
ports := map[int]bool{}
extract := func(p *api.Port) int { return p.HostPort }
// Respect the pod creation order when resolving conflicts.
sort.Sort(podsByCreationTime(pods))
for i := range pods {
pod := &pods[i]
if errs := validation.AccumulateUniquePorts(pod.Spec.Containers, ports, extract); len(errs) != 0 {
glog.Warningf("Pod %q: HostPort is already allocated, ignoring: %v", GetPodFullName(pod), errs)
record.Eventf(pod, "hostPortConflict", "Cannot start the pod due to host port conflict.")
// TODO: Set the pod status to fail.
continue
}
filtered = append(filtered, *pod)

View File

@ -3086,3 +3086,38 @@ func TestPortForward(t *testing.T) {
t.Fatalf("stream: expected %v, got %v", e, a)
}
}
// Tests that upon host port conflict, the newer pod is removed.
func TestFilterHostPortConflicts(t *testing.T) {
// Reuse the pod spec with the same port to create a conflict.
spec := api.PodSpec{Containers: []api.Container{{Ports: []api.Port{{HostPort: 80}}}}}
var pods = []api.BoundPod{
{
ObjectMeta: api.ObjectMeta{
UID: "123456789",
Name: "newpod",
Namespace: "foo",
},
Spec: spec,
},
{
ObjectMeta: api.ObjectMeta{
UID: "987654321",
Name: "oldpod",
Namespace: "foo",
},
Spec: spec,
},
}
// Make sure the BoundPods are in the reverse order of creation time.
pods[1].CreationTimestamp = util.NewTime(time.Now())
pods[0].CreationTimestamp = util.NewTime(time.Now().Add(1 * time.Second))
filteredPods := filterHostPortConflicts(pods)
if len(filteredPods) != 1 {
t.Fatalf("Expected one pod. Got pods %#v", filteredPods)
}
if filteredPods[0].Name != "oldpod" {
t.Fatalf("Expected pod %#v. Got pod %#v", pods[1], filteredPods[0])
}
}

View File

@ -44,6 +44,11 @@ func Now() Time {
return Time{time.Now()}
}
// Before reports whether the time instant t is before u.
func (t Time) Before(u Time) bool {
return t.Time.Before(u.Time)
}
// Unix returns the local time corresponding to the given Unix time
// by wrapping time.Unix.
func Unix(sec int64, nsec int64) Time {