add option to skip kubelet update

Author: YZ775

cluster.go

@@ -234,6 +234,7 @@ type KubeletParams struct {
 	CNIConfFile   CNIConfFile                `json:"cni_conf_file"`
 	Config        *unstructured.Unstructured `json:"config,omitempty"`
 	CRIEndpoint   string                     `json:"cri_endpoint"`
+	SkipUpdate    bool                       `json:"skip_update"`
 }
 
 // MergeConfig merges the input struct with `base`.

docs/cluster.md

@@ -230,7 +230,7 @@ Changing `KubeProxyConfiguration.Mode` requires full node restarts.
 
 ### KubeletParams
 
-| Name            | Required | Type                            | Description                                                             |
+|      Name       | Required |              Type               |                               Description                               |
 | --------------- | -------- | ------------------------------- | ----------------------------------------------------------------------- |
 | `boot_taints`   | false    | `[]Taint`                       | Bootstrap node taints.                                                  |
 | `cni_conf_file` | false    | `CNIConfFile`                   | CNI configuration file.                                                 |
@@ -239,6 +239,7 @@ Changing `KubeProxyConfiguration.Mode` requires full node restarts.
 | `extra_args`    | false    | array                           | Extra command-line arguments.  List of strings.                         |
 | `extra_binds`   | false    | array                           | Extra bind mounts.  List of `Mount`.                                    |
 | `extra_env`     | false    | object                          | Extra environment variables.                                            |
+| `skip_update`   | false    | bool                            | Skip update of the outdated kubelet.                                    |
 
 #### Boot taints
 

server/node_filter.go

@@ -446,6 +446,11 @@ func (nf *NodeFilter) RegisteredNodes(target []*cke.Node) (nodes []*cke.Node) {
 	return nodes
 }
 
+func (nf *NodeFilter) KubeletNeedUpgrade(node *cke.Node) bool {
+	st := nf.nodeStatus(node).Kubelet
+	return cke.KubernetesImage.Name() != st.Image
+}
+
 // KubeletOutdatedNodes returns nodes that are running kubelet with outdated image or params.
 func (nf *NodeFilter) KubeletOutdatedNodes() (nodes []*cke.Node) {
 	currentOpts := nf.cluster.Options.Kubelet

server/strategy.go

@@ -186,7 +186,7 @@ func k8sOps(c *cke.Cluster, nf *NodeFilter, cs *cke.ClusterStatus, maxConcurrent
 		}
 		ops = append(ops, k8s.KubeletBootOp(nodes[:max], nf.RegisteredNodes(nodes[:max]), apiServer, c.Name, c.Options.Kubelet, cs.NodeStatuses))
 	}
-	if nodes := nf.SSHConnectedNodes(nf.KubeletOutdatedNodes(), true, true); len(nodes) > 0 {
+	if nodes := nf.SSHConnectedNodes(nf.KubeletOutdatedNodes(), true, true); len(nodes) > 0 && !c.Options.Kubelet.SkipUpdate {
 		max := maxConcurrentUpdates
 		if len(nodes) < max {
 			max = len(nodes)

server/strategy_test.go

@@ -1012,6 +1012,15 @@ func TestDecideOps(t *testing.T) {
 				{"kubelet-restart", 2},
 			},
 		},
+		{
+			Name: "RestartKubelet10",
+			Input: newData().withAllServices().withKubelet("foo.local", "10.0.0.53", false).with(func(d testData) {
+				d.Cluster.Options.Kubelet.SkipUpdate = true
+			}).withSSHNotConnectedNodes(),
+			ExpectedOps: []opData{
+				{"wait-kubernetes", 1},
+			},
+		},
 		{
 			Name: "RestartProxy",
 			Input: newData().withAllServices().with(func(d testData) {