From a95eb6d8b8e2c0d9a2576819f664fa5e353c37a3 Mon Sep 17 00:00:00 2001
From: Mumshad Mannambeth <mmumshad@gmail.com>
Date: Sat, 13 Apr 2019 12:35:01 +0800
Subject: [PATCH] Create etcd-backup-and-restore.md

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 .../etcd-backup-and-restore.md                | 69 +++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 practice-questions-answers/etcd-backup-and-restore.md

diff --git a/practice-questions-answers/etcd-backup-and-restore.md b/practice-questions-answers/etcd-backup-and-restore.md
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+
+
+# 1. Get etcdctl utility if it's not already present.
+
+```
+go get github.com/coreos/etcd/etcdctl
+```
+
+# 2. Backup
+
+```
+ETCDCTL_API=3 etcdctl --endpoints=https://[127.0.0.1]:2379 --cacert=/etc/kubernetes/pki/etcd/ca.crt \
+     --cert=/etc/kubernetes/pki/etcd/server.crt --key=/etc/kubernetes/pki/etcd/server.key \
+     snapshot save /tmp/snapshot-pre-boot.db
+```
+
+# -----------------------------
+# Disaster Happens
+# -----------------------------
+
+# 3. Restore ETCD Snapshot to a new folder
+
+```
+ETCDCTL_API=3 etcdctl --endpoints=https://[127.0.0.1]:2379 --cacert=/etc/kubernetes/pki/etcd/ca.crt \
+     --name=master \
+     --cert=/etc/kubernetes/pki/etcd/server.crt --key=/etc/kubernetes/pki/etcd/server.key \
+     --data-dir /var/lib/etcd-from-backup \
+     --initial-cluster=master=https://127.0.0.1:2380 \
+     --initial-cluster-token etcd-cluster-1 \
+     --initial-advertise-peer-urls=https://127.0.0.1:2380 \
+     snapshot restore /tmp/snapshot-pre-boot.db
+```
+
+# 4. Modify /etc/kubernetes/manifests/etcd.yaml
+
+Update --data-dir to use new target location
+
+```
+--data-dir=/var/lib/etcd-from-backup
+```
+
+Update new initial-cluster-token to specify new cluster
+
+```
+--initial-cluster-token=etcd-cluster-1
+```
+
+Update volumes and volume mounts to point to new path
+
+```
+    volumeMounts:
+    - mountPath: /var/lib/etcd-from-backup
+      name: etcd-data
+    - mountPath: /etc/kubernetes/pki/etcd
+      name: etcd-certs
+  hostNetwork: true
+  priorityClassName: system-cluster-critical
+  volumes:
+  - hostPath:
+      path: /var/lib/etcd-from-backup
+      type: DirectoryOrCreate
+    name: etcd-data
+  - hostPath:
+      path: /etc/kubernetes/pki/etcd
+      type: DirectoryOrCreate
+    name: etcd-certs
+```
+
+> Note: You don't really need to update data directory and volumeMounts.mountPath path above. You could simply just update the hostPath.path in the volumes section to point to the new directory. But if you are not working with a kubeadm deployed cluster, then you might have to update the data directory. That's why I left it as is.