Merge pull request #7881 from ahardin-rh/oc-adm-drain-39

Added oc adm drain options for 3.9

Author: ahardin-rh

admin_guide/manage_nodes.adoc

@@ -27,15 +27,13 @@ xref:../architecture/infrastructure_components/kubernetes_infrastructure.adoc#no
 == Listing Nodes
 To list all nodes that are known to the master:
 
-====
 ----
 $ oc get nodes
 NAME                        STATUS                     AGE
 master.example.com          Ready,SchedulingDisabled   165d
 node1.example.com           Ready                      165d
 node2.example.com           Ready                      165d
 ----
-====
 
 To only list information about a single node, replace `<node>` with the full
 node name:
@@ -78,7 +76,6 @@ $ oc describe node <node>
 
 For example:
 
-====
 ----
 $ oc describe node node1.example.com
 Name:			node1.example.com
@@ -104,7 +101,6 @@ Pods:				(2 in total)
   router-1-maytv
 No events.
 ----
-====
 
 [[adding-nodes]]
 == Adding Nodes
@@ -208,14 +204,12 @@ $ oc adm manage-node <node1> <node2> --schedulable=false
 
 For example:
 
-====
 [options="nowrap"]
 ----
 $ oc adm manage-node node1.example.com --schedulable=false
 NAME                 LABELS                                        STATUS
 node1.example.com    kubernetes.io/hostname=node1.example.com      Ready,SchedulingDisabled
 ----
-====
 
 To mark a currently unschedulable node or nodes as schedulable:
 
@@ -241,10 +235,10 @@ controller] can be evacuated; the replication controllers create new pods on
 other nodes and remove the existing pods from the specified node(s). Bare pods,
 meaning those not backed by a replication controller, are unaffected by default.
 
-To evacuate one or more nodes:
+To evacuate all or selected pods on one or more nodes:
 
 ----
-$ oc adm drain <node1> <node2>
+$ oc adm drain <node1> <node2> [--pod-selector=<pod_selector>]
 ----
 
 You can force deletion of bare pods by using the `--force` option. When set to
@@ -292,6 +286,10 @@ use the `--dry-run` option and set it to `true`:
 $ oc adm drain <node1> <node2>  --dry-run=true
 ----
 
+Instead of specifying specific node names (for example, `<node1> <node2>`), you
+can use the `--selector=<node_selector>` option to evacuate pods on selected
+nodes.
+
 [[rebooting-nodes]]
 == Rebooting Nodes
 
@@ -346,7 +344,6 @@ this feature is to set the `*scheduler.alpha.kubernetes.io/affinity*` on the
 pod. Since this pod uses a deployment configuration, the most appropriate
 place to add the annotation is to the pod template's metadata.
 
-====
 ----
 $ oc edit dc/docker-registry -o yaml
 
@@ -370,7 +367,6 @@ $ oc edit dc/docker-registry -o yaml
             }
           }
 ----
-====
 
 [IMPORTANT]
 ====
@@ -414,7 +410,6 @@ You can configure node resources by adding kubelet arguments to the node
 configuration file (*_/etc/origin/node/node-config.yaml_*). Add the
 `*kubeletArguments*` section and include any desired options:
 
-====
 ----
 kubeletArguments:
   max-pods: <1>
@@ -434,7 +429,6 @@ resolution configuration.
 Default: 90%
 <4> The percent of disk usage before which image garbage collection is never run.
 Lowest disk usage to garbage collect to. Default: 80%
-====
 
 To view all available kubelet options:
 
@@ -446,11 +440,9 @@ This can also be set during an
 xref:../install_config/install/advanced_install.adoc#configuring-ansible[advanced
 installation] using the `*openshift_node_kubelet_args*` variable. For example:
 
-====
 ----
 openshift_node_kubelet_args={'max-pods': ['40'], 'resolv-conf': ['/etc/resolv.conf'],  'image-gc-high-threshold': ['90'], 'image-gc-low-threshold': ['80']}
 ----
-====
 
 [[admin-guide-max-pods-per-node]]
 === Setting Maximum Pods Per Node
@@ -483,13 +475,11 @@ processor cores on the node. For example, if `pods-per-core` is set to `10` on
 a node with 4 processor cores, the maximum number of pods allowed on the node
 will be 40.
 
-====
 ----
 kubeletArguments:
   pods-per-core:
     - "10"
 ----
-====
 
 [NOTE]
 ====
@@ -499,13 +489,11 @@ Setting `pods-per-core` to 0 disables this limit.
 `max-pods` sets the number of pods the node can run to a fixed value, regardless
 of the properties of the node.
 
-====
 ----
 kubeletArguments:
   max-pods:
     - "250"
 ----
-====
 
 Using the above example, the default value for `pods-per-core` is `10` and the
 default value for `max-pods` is `250`. This means that unless the node has 25
@@ -622,6 +610,7 @@ To change the node traffic interface:
 
 . Set the `*openshift_set_node_ip*` Ansible variable to `true`.
 . Set the `*openshift_ip*` to the IP address for the node you want to configure.
+
 [NOTE]
 ====
 Although  `*openshift_set_node_ip*` can be useful as a workaround for the