If no etcd was deployed, fail etcd-snapshot with a useful error

Signed-off-by: manuelbuil <[email protected]>

pkg/cli/etcdsnapshot/etcd_snapshot.go

@@ -82,10 +82,26 @@ func commandSetup(app *cli.Context, cfg *cmds.Server) (*etcd.SnapshotRequest, *c
 		}
 		cfg.Token = string(bytes.TrimRight(tokenByte, "\n"))
 	}
+
+	if !etcdRunning(dataDir) {
+		return nil, nil, errors.New("K3s is not deployed with an etcd datastore")
+	}
+
 	info, err := clientaccess.ParseAndValidateToken(cmds.ServerConfig.ServerURL, cfg.Token, clientaccess.WithUser("server"))
 	return sr, info, err
 }
 
+// etcdRunning checks if etcd is the datastore
+func etcdRunning(dataDir string) bool {
+	// if kine.sock is present and db/etcd/config is not, we are not using etcd. Only one of them missing could also mean a wrong dataDir
+	_, errEtcd := os.Stat(filepath.Join(dataDir, "db/etcd/config"))
+	_, errKine := os.Stat(filepath.Join(dataDir, "kine.sock"))
+	if os.IsNotExist(errEtcd) && !os.IsNotExist(errKine) {
+		return false
+	}
+	return true
+}
+
 func wrapServerError(err error) error {
 	if errors.Is(err, context.DeadlineExceeded) {
 		// if the request timed out the server log likely won't contain anything useful,