実行
systemctl start docker
エラー
Failed to start docker.service: Unit docker.service is masked.
解きます
systemctl unmask docker.service
systemctl unmask docker.socket
systemctl start docker.service
実行
systemctl start docker
エラー
Failed to start docker.service: Unit docker.service is masked.
解きます
systemctl unmask docker.service
systemctl unmask docker.socket
systemctl start docker.service