ocp4 sops moved into sysadmin_guide

Signed-off-by: David Kirwan <davidkirwanirl@gmail.com>

modules/sysadmin_guide/pages/sop_graceful_shutdown_ocp_cluster.adoc

@@ -0,0 +1,30 @@
+= Graceful Shutdown of an Openshift 4 Cluster
+This SOP should be followed in the following scenarios:
+
+- Graceful full shut down of the Openshift 4 cluster is required.
+
+== Steps
+
+Prequisite steps:
+- Follow the SOP for cordoning and draining the nodes.
+- Follow the SOP for creating an `etcd` backup.
+
+
+1. Connect to the `os-control01` host associated with this ENV. Become root `sudo su -`.
+
+2. Get a list of the nodes
++
+----
+nodes=$(oc get nodes -o name  | sed -E "s/node\///")
+----
+
+3. Shutdown the nodes from the administration box associated with the cluster `ENV` eg production/staging.
++
+----
+for node in ${nodes[@]}; do ssh -i /root/ocp4/ocp-<ENV>/ssh/id_rsa core@$node sudo shutdown -h now; done
+----
+
+
+=== Resources
+
+- [1] https://docs.openshift.com/container-platform/4.5/backup_and_restore/graceful-cluster-shutdown.html[Graceful Cluster Shutdown]