77 lines
3.1 KiB
Markdown
77 lines
3.1 KiB
Markdown
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# 1. Get etcdctl utility if it's not already present.
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Reference: https://github.com/etcd-io/etcd/releases
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```
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ETCD_VER=v3.4.9
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# choose either URL
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GOOGLE_URL=https://storage.googleapis.com/etcd
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GITHUB_URL=https://github.com/etcd-io/etcd/releases/download
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DOWNLOAD_URL=${GOOGLE_URL}
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rm -f /tmp/etcd-${ETCD_VER}-linux-amd64.tar.gz
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rm -rf /tmp/etcd-download-test && mkdir -p /tmp/etcd-download-test
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curl -L ${DOWNLOAD_URL}/${ETCD_VER}/etcd-${ETCD_VER}-linux-amd64.tar.gz -o /tmp/etcd-${ETCD_VER}-linux-amd64.tar.gz
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tar xzvf /tmp/etcd-${ETCD_VER}-linux-amd64.tar.gz -C /tmp/etcd-download-test --strip-components=1
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rm -f /tmp/etcd-${ETCD_VER}-linux-amd64.tar.gz
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/tmp/etcd-download-test/etcd --version
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ETCDCTL_API=3 /tmp/etcd-download-test/etcdctl version
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mv /tmp/etcd-download-test/etcdctl /usr/bin
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```
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# 2. Backup
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```
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ETCDCTL_API=3 etcdctl --endpoints=https://[127.0.0.1]:2379 --cacert=/etc/kubernetes/pki/etcd/ca.crt \
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--cert=/etc/kubernetes/pki/etcd/server.crt --key=/etc/kubernetes/pki/etcd/server.key \
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snapshot save /opt/snapshot-pre-boot.db
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```
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Note: In this case, the **ETCD** is running on the same server where we are running the commands (which is the *controlplane* node). As a result, the **--endpoint** argument is optional and can be ignored.
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The options **--cert, --cacert and --key** are mandatory to authenticate to the ETCD server to take the backup.
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If you want to take a backup of the ETCD service running on a different machine, you will have to provide the correct endpoint to that server (which is the IP Address and port of the etcd server with the **--endpoint** argument)
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# -----------------------------
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# Disaster Happens
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# -----------------------------
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# 3. Restore ETCD Snapshot to a new folder
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```
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ETCDCTL_API=3 etcdctl --data-dir /var/lib/etcd-from-backup \
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snapshot restore /opt/snapshot-pre-boot.db
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```
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Note: In this case, we are restoring the snapshot to a different directory but in the same server where we took the backup (**the controlplane node)**
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As a result, the only required option for the restore command is the **--data-dir**.
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# 4. Modify /etc/kubernetes/manifests/etcd.yaml
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Update ETCD POD to use the new hostPath directory `/var/lib/etcd-from-backup` 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 this is a static pod placed under the `/etc/kubernetes/manifests` directory.
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Update volumes and volume mounts to point to new path
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```
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volumes:
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- hostPath:
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path: /var/lib/etcd-from-backup
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type: DirectoryOrCreate
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name: etcd-data
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- hostPath:
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path: /etc/kubernetes/pki/etcd
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type: DirectoryOrCreate
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name: etcd-certs
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```
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> Note: as the ETCD pod has changed it will automatically restart, and also kube-controller-manager and kube-scheduler. Wait 1-2 to mins for this pods to restart. You can make a `watch "docker ps | grep etcd"` to see when the ETCD pod is restarted.
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> Note2: If the etcd pod is not getting `Ready 1/1`, then restart it by `kubectl delete pod -n kube-system etcd-controlplane` and wait 1 minute.
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