From 63e92d719ac7da5f5d11affb9a88f34983c287f2 Mon Sep 17 00:00:00 2001
From: "andrew.k" <andriikrymus@gmail.com>
Date: Wed, 7 Jul 2021 23:42:23 +0300
Subject: [PATCH] Clarify first master replace (#7761)

* Update nodes.md

* fix syntax

* fix syntax - part 2

* replace master with kube_control_plane

* return etcd-master
---
 docs/nodes.md | 47 +++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 43 insertions(+), 4 deletions(-)

diff --git a/docs/nodes.md b/docs/nodes.md
index 595e3aff4..56e67bea3 100644
--- a/docs/nodes.md
+++ b/docs/nodes.md
@@ -69,8 +69,8 @@ Before using `--limit` run playbook `facts.yml` without the limit to refresh fac
 ### 3) Remove an old node with remove-node.yml
 
 With the old node still in the inventory, run `remove-node.yml`. You need to pass `-e node=NODE_NAME` to the playbook to limit the execution to the node being removed.
-  
-If the node you want to remove is not online, you should add `reset_nodes=false` to your extra-vars: `-e node=NODE_NAME -e reset_nodes=false`.
+
+If the node you want to remove is not online, you should add `reset_nodes=false` and `allow_ungraceful_removal=true` to your extra-vars: `-e node=NODE_NAME -e reset_nodes=false -e allow_ungraceful_removal=true`.
 Use this flag even when you remove other types of nodes like a control plane or etcd nodes.
 
 ### 4) Remove the node from the inventory
@@ -95,7 +95,46 @@ docker ps | grep k8s_nginx-proxy_nginx-proxy | awk '{print $1}' | xargs docker r
 ### 3) Remove old control plane nodes
 
 With the old node still in the inventory, run `remove-node.yml`. You need to pass `-e node=NODE_NAME` to the playbook to limit the execution to the node being removed.
-If the node you want to remove is not online, you should add `reset_nodes=false` to your extra-vars.
+If the node you want to remove is not online, you should add `reset_nodes=false` and `allow_ungraceful_removal=true` to your extra-vars.
+
+## Replacing a first control plane node
+
+### 1) Change control plane nodes order in inventory
+
+from
+
+```ini
+[kube_control_plane]
+ node-1
+ node-2
+ node-3
+```
+
+to
+
+```ini
+[kube_control_plane]
+ node-2
+ node-3
+ node-1
+```
+
+### 2) Remove old first control plane node from cluster
+
+With the old node still in the inventory, run `remove-node.yml`. You need to pass `-e node=node-1` to the playbook to limit the execution to the node being removed.
+If the node you want to remove is not online, you should add `reset_nodes=false` and `allow_ungraceful_removal=true` to your extra-vars.
+
+### 3) Edit cluster-info configmap in kube-system namespace
+
+`kubectl  edit cm -n kube-public cluster-info`
+
+Change ip of old kube_control_plane node with ip of live kube_control_plane node (`server` field). Also, update `certificate-authority-data` field if you changed certs.
+
+### 4) Add new control plane node
+
+Update inventory (if needed)
+
+Run `cluster.yml` with `--limit=kube_control_plane`
 
 ## Adding an etcd node
 
@@ -124,7 +163,7 @@ In every control plane node, edit `/etc/kubernetes/manifests/kube-apiserver.yaml
 ### 1) Remove an old etcd node
 
 With the node still in the inventory, run `remove-node.yml` passing `-e node=NODE_NAME` as the name of the node that should be removed.
-If the node you want to remove is not online, you should add `reset_nodes=false` to your extra-vars.
+If the node you want to remove is not online, you should add `reset_nodes=false` and `allow_ungraceful_removal=true` to your extra-vars.
 
 ### 2) Make sure only remaining nodes are in your inventory