[Unit]
Description=/var/log/wtmp import
Documentation=man:wtmpd(8)
After=local-fs.target
ConditionPathExists=/var/log/wtmp
ConditionPathExists=!/var/lib/wtmpdb/wtmp.db

[Service]
Type=oneshot
#ExecStartPre=/usr/bin/systemd-tmpfiles --create wtmpdb.conf
ExecStartPre=/usr/bin/cp -p /var/log/wtmp /var/log/wtmp.migrated
ExecStartPre=/usr/bin/cp /dev/null /var/log/wtmp
ExecStart=/usr/bin/wtmpdb import /var/log/wtmp.migrated
ExecStartPost=-systemctl enable wtmpdb-update-boot
ExecStartPost=-systemctl start wtmpdb-update-boot
RemainAfterExit=true

[Install]
WantedBy=default.target