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Backup and Restore Methods

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In this section, we will take a look at backup and restore methods

Backup Candidates

Resource Configuration

• Imperative way

  

• Declarative Way (Preferred approach) ``` apiVersion: v1 kind: Pod metadata: name: myapp-pod labels: app: myapp type: front-end spec: containers:
  • name: nginx-container image: nginx ```

• A good practice is to store resource configurations on source code repositories like github.

  

Backup - Resource Configs

  $ kubectl get all --all-namespaces -o yaml > all-deploy-services.yaml (only for few resource groups)

• There are many other resource groups that must be considered. There are tools like ARK or now called Velero by Heptio that can do this for you.

  

Backup - ETCD

• So, instead of backing up resources as before, you may choose to backup the ETCD cluster itself.

  

• You can take a snapshot of the etcd database by using etcdctl utility snapshot save command.

  $ ETCDCTL_API=3 etcdctl snapshot save snapshot.db
  

  $  ETCDCTL_API=3 etcdctl snapshot status snapshot.db
  

  

Restore - ETCD

• To restore etcd from the backup at later in time. First stop kube-apiserver service

  $ service kube-apiserver stop
  

• Run the etcdctl snapshot restore command
• Update the etcd service
• Reload system configs

  $ systemctl daemon-reload
  

• Restart etcd

  $ service etcd restart
  

  

• Start the kube-apiserver

  $ service kube-apiserver start
  

  With all etcdctl commands specify the cert,key,cacert and endpoint for authentication.

  $ ETCDCTL_API=3 etcdctl \
  snapshot save /tmp/snapshot.db \
  --endpoints=https://[127.0.0.1]:2379 \
  --cacert=/etc/kubernetes/pki/etcd/ca.crt \
  --cert=/etc/kubernetes/pki/etcd/etcd-server.crt \
  --key=/etc/kubernetes/pki/etcd/etcd-server.key
  

  

K8s Reference Docs

• https://kubernetes.io/docs/tasks/administer-cluster/configure-upgrade-etcd/