Add --force to kubectl delete and explain force deletion

hack/lib/test.sh

@@ -23,7 +23,7 @@ readonly   red=$(tput setaf 1)
 readonly green=$(tput setaf 2)
 
 kube::test::clear_all() {
-  kubectl delete "${kube_flags[@]}" rc,pods --all --grace-period=0
+  kubectl delete "${kube_flags[@]}" rc,pods --all --grace-period=0 --force
 }
 
 # Force exact match of a returned result for a object query.  Wrap this with || to support multiple

hack/make-rules/test-cmd.sh

@@ -473,7 +473,7 @@ runTests() {
   # Pre-condition: valid-pod POD exists
   kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'valid-pod:'
   # Command
-  kubectl delete pod valid-pod "${kube_flags[@]}" --grace-period=0
+  kubectl delete pod valid-pod "${kube_flags[@]}" --grace-period=0 --force
   # Post-condition: valid-pod POD doesn't exist
   kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" ''
 
@@ -486,6 +486,17 @@ runTests() {
   # Post-condition: valid-pod POD doesn't exist
   kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" ''
 
+  ### Delete POD valid-pod by id with --grace-period=0
+  # Pre-condition: valid-pod POD exists
+  kubectl create "${kube_flags[@]}" -f test/fixtures/doc-yaml/admin/limitrange/valid-pod.yaml
+  kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'valid-pod:'
+  # Command fails without --force
+  ! kubectl delete pod valid-pod "${kube_flags[@]}" --grace-period=0
+  # Command succeds with --force
+  kubectl delete pod valid-pod "${kube_flags[@]}" --grace-period=0 --force
+  # Post-condition: valid-pod POD doesn't exist
+  kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" ''
+
   ### Create POD valid-pod from dumped YAML
   # Pre-condition: no POD exists
   create_and_use_new_namespace
@@ -499,7 +510,7 @@ runTests() {
   # Pre-condition: valid-pod POD exists
   kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'valid-pod:'
   # Command
-  kubectl delete -f test/fixtures/doc-yaml/admin/limitrange/valid-pod.yaml "${kube_flags[@]}" --grace-period=0
+  kubectl delete -f test/fixtures/doc-yaml/admin/limitrange/valid-pod.yaml "${kube_flags[@]}" --grace-period=0 --force
   # Post-condition: valid-pod POD doesn't exist
   kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" ''
 
@@ -516,7 +527,7 @@ runTests() {
   # Pre-condition: valid-pod POD exists
   kube::test::get_object_assert "pods -l'name in (valid-pod)'" '{{range.items}}{{$id_field}}:{{end}}' 'valid-pod:'
   # Command
-  kubectl delete pods -l'name in (valid-pod)' "${kube_flags[@]}" --grace-period=0
+  kubectl delete pods -l'name in (valid-pod)' "${kube_flags[@]}" --grace-period=0 --force
   # Post-condition: valid-pod POD doesn't exist
   kube::test::get_object_assert "pods -l'name in (valid-pod)'" '{{range.items}}{{$id_field}}:{{end}}' ''
 
@@ -549,7 +560,7 @@ runTests() {
   # Pre-condition: valid-pod POD exists
   kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'valid-pod:'
   # Command
-  kubectl delete --all pods "${kube_flags[@]}" --grace-period=0 # --all remove all the pods
+  kubectl delete --all pods "${kube_flags[@]}" --grace-period=0 --force # --all remove all the pods
   # Post-condition: no POD exists
   kube::test::get_object_assert "pods -l'name in (valid-pod)'" '{{range.items}}{{$id_field}}:{{end}}' ''
 
@@ -607,7 +618,7 @@ runTests() {
   # Pre-condition: valid-pod and redis-proxy PODs exist
   kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'redis-proxy:valid-pod:'
   # Command
-  kubectl delete pods valid-pod redis-proxy "${kube_flags[@]}" --grace-period=0 # delete multiple pods at once
+  kubectl delete pods valid-pod redis-proxy "${kube_flags[@]}" --grace-period=0 --force # delete multiple pods at once
   # Post-condition: no POD exists
   kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" ''
 
@@ -669,7 +680,7 @@ runTests() {
   # Pre-condition: valid-pod POD exists
   kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'valid-pod:'
   # Command
-  kubectl delete pods -lnew-name=new-valid-pod --grace-period=0 "${kube_flags[@]}"
+  kubectl delete pods -lnew-name=new-valid-pod --grace-period=0 --force "${kube_flags[@]}"
   # Post-condition: valid-pod POD doesn't exist
   kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" ''
 
@@ -896,7 +907,7 @@ __EOF__
   # Pre-condition: valid-pod POD exists
   kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'valid-pod:'
   # Command
-  kubectl delete pods -l'name in (valid-pod-super-sayan)' --grace-period=0 "${kube_flags[@]}"
+  kubectl delete pods -l'name in (valid-pod-super-sayan)' --grace-period=0 --force "${kube_flags[@]}"
   # Post-condition: valid-pod POD doesn't exist
   kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" ''
 
@@ -1462,7 +1473,7 @@ __EOF__
   # Pre-condition: busybox0 & busybox1 PODs exist
   kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'busybox0:busybox1:'
   # Command
-  output_message=$(! kubectl delete -f hack/testdata/recursive/pod --recursive --grace-period=0 2>&1 "${kube_flags[@]}")
+  output_message=$(! kubectl delete -f hack/testdata/recursive/pod --recursive --grace-period=0 --force 2>&1 "${kube_flags[@]}")
   # Post-condition: busybox0 & busybox1 PODs are deleted, and since busybox2 is malformed, it should error
   kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" ''
   kube::test::if_has_string "${output_message}" "Object 'Kind' is missing"
@@ -1521,7 +1532,7 @@ __EOF__
   # Pre-condition: busybox0 & busybox1 PODs exist
   kube::test::get_object_assert rc "{{range.items}}{{$id_field}}:{{end}}" 'busybox0:busybox1:'
   # Command
-  output_message=$(! kubectl delete -f hack/testdata/recursive/rc --recursive --grace-period=0 2>&1 "${kube_flags[@]}")
+  output_message=$(! kubectl delete -f hack/testdata/recursive/rc --recursive --grace-period=0 --force 2>&1 "${kube_flags[@]}")
   # Post-condition: busybox0 & busybox1 replication controllers are deleted, and since busybox2 is malformed, it should error
   kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" ''
   kube::test::if_has_string "${output_message}" "Object 'Kind' is missing"
@@ -1561,7 +1572,7 @@ __EOF__
   # Clean up
   unset PRESERVE_ERR_FILE
   rm "${ERROR_FILE}"
-  ! kubectl delete -f hack/testdata/recursive/deployment --recursive "${kube_flags[@]}" --grace-period=0
+  ! kubectl delete -f hack/testdata/recursive/deployment --recursive "${kube_flags[@]}" --grace-period=0 --force
   sleep 1
 
   ### Rollout on multiple replication controllers recursively - these tests ensure that rollouts cannot be performed on resources that don't support it
@@ -1590,7 +1601,7 @@ __EOF__
   kube::test::if_has_string "${output_message}" 'replicationcontrollers "busybox0" resuming is not supported'
   kube::test::if_has_string "${output_message}" 'replicationcontrollers "busybox0" resuming is not supported'
   # Clean up
-  ! kubectl delete -f hack/testdata/recursive/rc --recursive "${kube_flags[@]}" --grace-period=0
+  ! kubectl delete -f hack/testdata/recursive/rc --recursive "${kube_flags[@]}" --grace-period=0 --force
   sleep 1
 
   ##############
@@ -1637,7 +1648,7 @@ __EOF__
   # Pre-condition: valid-pod POD exists
   kube::test::get_object_assert 'pods --namespace=other' "{{range.items}}{{$id_field}}:{{end}}" 'valid-pod:'
   # Command
-  kubectl delete "${kube_flags[@]}" pod --namespace=other valid-pod --grace-period=0
+  kubectl delete "${kube_flags[@]}" pod --namespace=other valid-pod --grace-period=0 --force
   # Post-condition: valid-pod POD doesn't exist
   kube::test::get_object_assert 'pods --namespace=other' "{{range.items}}{{$id_field}}:{{end}}" ''
   # Clean up
@@ -2848,7 +2859,7 @@ __EOF__
   # Pre-condition: valid-pod exists
   kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'valid-pod:'
   # Command
-  kubectl delete "${kube_flags[@]}" pod valid-pod --grace-period=0
+  kubectl delete "${kube_flags[@]}" pod valid-pod --grace-period=0 --force
   # Post-condition: valid-pod doesn't exist
   kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" ''
 

pkg/kubectl/cmd/delete.go

@@ -36,9 +36,26 @@ var (
 	delete_long = templates.LongDesc(`
 		Delete resources by filenames, stdin, resources and names, or by resources and label selector.
 
-		JSON and YAML formats are accepted.
-
-		Only one type of the arguments may be specified: filenames, resources and names, or resources and label selector
+		JSON and YAML formats are accepted. Only one type of the arguments may be specified: filenames,
+		resources and names, or resources and label selector.
+
+		Some resources, such as pods, support graceful deletion. These resources define a default period
+		before they are forcibly terminated (the grace period) but you may override that value with
+		the --grace-period flag, or pass --now to set a grace-period of 1. Because these resources often
+		represent entities in the cluster, deletion may not be acknowledged immediately. If the node
+		hosting a pod is down or cannot reach the API server, termination may take significantly longer
+		than the grace period. To force delete a resource,	you must pass a grace	period of 0 and specify
+		the --force flag.
+
+		IMPORTANT: Force deleting pods does not wait for confirmation that the pod's processes have been
+		terminated, which can leave those processes running until the node detects the deletion and
+		completes graceful deletion. If your processes use shared storage or talk to a remote API and
+		depend on the name of the pod to identify themselves, force deleting those pods may result in
+		multiple processes running on different machines using the same identification which may lead
+		to data corruption or inconsistency. Only force delete pods when you are sure the pod is
+		terminated, or if your application can tolerate multiple copies of the same pod running at once.
+		Also, if you force delete pods the scheduler may place new pods on those nodes before the node
+		has released those resources and causing those pods to be evicted immediately.
 
 		Note that the delete command does NOT do resource version checks, so if someone
 		submits an update to a resource right when you submit a delete, their update
@@ -57,9 +74,12 @@ var (
 		# Delete pods and services with label name=myLabel.
 		kubectl delete pods,services -l name=myLabel
 
-		# Delete a pod immediately (no graceful shutdown)
+		# Delete a pod with minimal delay
 		kubectl delete pod foo --now
 
+		# Force delete a pod on a dead node
+		kubectl delete pod foo --grace-period=0 --force
+
 		# Delete a pod with UID 1234-56-7890-234234-456456.
 		kubectl delete pod 1234-56-7890-234234-456456
 
@@ -102,7 +122,8 @@ func NewCmdDelete(f cmdutil.Factory, out io.Writer) *cobra.Command {
 	cmd.Flags().Bool("ignore-not-found", false, "Treat \"resource not found\" as a successful delete. Defaults to \"true\" when --all is specified.")
 	cmd.Flags().Bool("cascade", true, "If true, cascade the deletion of the resources managed by this resource (e.g. Pods created by a ReplicationController).  Default true.")
 	cmd.Flags().Int("grace-period", -1, "Period of time in seconds given to the resource to terminate gracefully. Ignored if negative.")
-	cmd.Flags().Bool("now", false, "If true, resources are force terminated without graceful deletion (same as --grace-period=0).")
+	cmd.Flags().Bool("now", false, "If true, resources are signaled for immediate shutdown (same as --grace-period=1).")
+	cmd.Flags().Bool("force", false, "Immediate deletion of some resources may result in inconsistency or data loss and requires confirmation.")
 	cmd.Flags().Duration("timeout", 0, "The length of time to wait before giving up on a delete, zero means determine a timeout from the size of the object")
 	cmdutil.AddOutputFlagsForMutation(cmd)
 	cmdutil.AddInclude3rdPartyFlags(cmd)
@@ -148,7 +169,10 @@ func RunDelete(f cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []stri
 		if gracePeriod != -1 {
 			return fmt.Errorf("--now and --grace-period cannot be specified together")
 		}
-		gracePeriod = 0
+		gracePeriod = 1
+	}
+	if gracePeriod == 0 && !cmdutil.GetFlagBool(cmd, "force") {
+		return fmt.Errorf("Immediate deletion does not wait for confirmation that the running resource has been terminated. The resource may continue to run on the cluster indefinitely. You must pass --force to delete with grace period 0.")
 	}
 
 	shortOutput := cmdutil.GetFlagString(cmd, "output") == "name"

test/e2e/kubectl.go

@@ -144,7 +144,7 @@ func cleanupKubectlInputs(fileContents string, ns string, selectors ...string) {
 	}
 	// support backward compatibility : file paths or raw json - since we are removing file path
 	// dependencies from this test.
-	framework.RunKubectlOrDieInput(fileContents, "delete", "--grace-period=0", "-f", "-", nsArg)
+	framework.RunKubectlOrDieInput(fileContents, "delete", "--grace-period=0", "--force", "-f", "-", nsArg)
 	framework.AssertCleanup(ns, selectors...)
 }