Prerequisites
Within the cluster nodes that act only as etcd, the executable files are probably already present.
To be able to back up a k8s cluster, first we need the executable file etcdctl, downloadable from here (choose the appropriate release). After that, unpack the archive file (this results in a directory containing the binaries) and add the executable binaries to your path (i.e. /usr/local/bin)
# For example, let's download release 3.5.4 $ wget https://github.com/etcd-io/etcd/releases/download/v3.5.4/etcd-v3.5.4-linux-amd64.tar.gz $ tar xzvf etcd-v3.5.4-linux-amd64.tar.gz $ sudo cp etcd-v3.5.4-linux-amd64/etcdctl /usr/local/bin/ $ etcdctl version etcdctl version: 3.5.4 API version: 3.5
Once we have the executable file, we need the certificates to be able to communicate with the etcd node(s). If you don't know the location of the certificates, you can retrieve it using the grep command in the /etc/kubernetes folder on the master node. Save the location of the certificates in the following environment variables
# Insert the following lines inside the ".bashrc" file, then use "$ source .bashrc" to apply the changes export ETCDCTL_CERT=/<path>/cert.pem export ETCDCTL_CACERT=/<path>/ca.pem export ETCDCTL_KEY=/<path>/key.pem
Save and Restore
If you have an etcd cluster, you can select only one node, otherwise you get the error snapshot must be requested to one selected node, not multiple.
Take a snapshot of the etcd datastore using the following command, which generates the file <snapshot_file>
$ etcdctl snapshot save <snapshot_file> --endpoints=<endpoint>:<port> # Instead of <endpoint> you can substitute a hostname or an IP $ etcdctl snapshot save snapshot.db --endpoints=etcd1:2379 $ etcdctl snapshot save snapshot.db --endpoints=192.168.100.88:2379