Backup and Restore

Resource configuration backup
kunectl get all —all-namespaces -o yaml > all-deploy-service.yaml

etcd backup n restore
복구시
token n data 경로는 원래 것과 다르게 해야한다

# 1. Get etcdctl utility if it's not already present.

Reference: https://github.com/etcd-io/etcd/releases

```
ETCD_VER=v3.3.13

# choose either URL
GOOGLE_URL=https://storage.googleapis.com/etcd
GITHUB_URL=https://github.com/etcd-io/etcd/releases/download
DOWNLOAD_URL=${GOOGLE_URL}

rm -f /tmp/etcd-${ETCD_VER}-linux-amd64.tar.gz
rm -rf /tmp/etcd-download-test && mkdir -p /tmp/etcd-download-test

curl -L ${DOWNLOAD_URL}/${ETCD_VER}/etcd-${ETCD_VER}-linux-amd64.tar.gz -o /tmp/etcd-${ETCD_VER}-linux-amd64.tar.gz
tar xzvf /tmp/etcd-${ETCD_VER}-linux-amd64.tar.gz -C /tmp/etcd-download-test --strip-components=1
rm -f /tmp/etcd-${ETCD_VER}-linux-amd64.tar.gz

/tmp/etcd-download-test/etcd --version
ETCDCTL_API=3 /tmp/etcd-download-test/etcdctl version

mv /tmp/etcd-download-test/etcdctl /usr/bin
```

# 2. Backup
minikube의 경우 /etc/kubernetes/mainifests/kube-apiserver.yaml 참조

```
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 ETCD POD to use the new data directory and cluster token by modifying the pod definition file at `/etc/kubernetes/manifests/etcd.yaml`. When this file is updated, the ETCD pod is automatically re-created as thisis a static pod placed under the `/etc/kubernetes/manifests` directory.

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.

만약 pod로 구성되지 않았다면 snap save 후
ETCDCTL_API=3 etcdctl snapshot status snapshot.db


service kube-apiserver stop

모든 수정작업이 완료된후에는

systemctl daemon-reload
servicec etcd restart
service kube-apiserver start