#!/bin/bash
#
# Nightly mirror of Oracle backups + cluster config to pve1's backup-ssd.
#
# Why two redundant copies are not enough:
#   * ZFS replica pveelite -> pvemini covers pveelite hardware failure.
#   * If both pveelite AND pvemini are down (rare but possible — common
#     storage controller, network rack, electrical fault), pve1 is the
#     last copy. Keeping it on a different physical disk type (SATA
#     ext4) further insulates against ZFS-on-NVMe-specific failures.
#   * /etc/pve is in pmxcfs (in-RAM, replicated cluster-wide). If
#     quorum is lost on multiple nodes simultaneously the config is
#     unrecoverable without a backup.
#
# Schedule (cron on pveelite): 0 4 * * *

set -euo pipefail
export PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"

PVE1_HOST="10.0.20.200"
PVE1_BACKUP_DIR="/mnt/pve/backup-ssd"
ORACLE_SRC="/mnt/pve/oracle-backups/"
ORACLE_DST="${PVE1_BACKUP_DIR}/oracle-backups-mirror/"
PVE_CFG_DST="${PVE1_BACKUP_DIR}/pve-config-backups"
LOG="/var/log/oracle-dr/nightly-mirror.log"
SSH_OPTS="-o UserKnownHostsFile=/etc/pve/priv/known_hosts -o StrictHostKeyChecking=no -o BatchMode=yes"
KEEP_PVE_CONFIGS=14   # 2 weeks of nightly /etc/pve archives

mkdir -p "$(dirname "$LOG")"

log() { echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*" >>"$LOG"; }

log "=== Starting nightly mirror ==="

# 1. Rsync Oracle backups to pve1
log "Rsync ${ORACLE_SRC} -> ${PVE1_HOST}:${ORACLE_DST}"
if rsync -aHX --delete -e "ssh ${SSH_OPTS}" \
        "${ORACLE_SRC}" "root@${PVE1_HOST}:${ORACLE_DST}" 2>>"$LOG"; then
    log "Oracle backups rsync OK"
else
    log "ERROR: Oracle backups rsync failed"
fi

# 2. Tar /etc/pve and ship to pve1
TS=$(date +%Y%m%d_%H%M%S)
ARCHIVE="pve-config-${TS}.tar.gz"
log "Tar /etc/pve -> ${PVE1_HOST}:${PVE_CFG_DST}/${ARCHIVE}"
if tar czf - -C / etc/pve 2>/dev/null | \
        ssh ${SSH_OPTS} "root@${PVE1_HOST}" \
            "cat > '${PVE_CFG_DST}/${ARCHIVE}'" 2>>"$LOG"; then
    log "pve-config tar OK ($(ssh ${SSH_OPTS} root@${PVE1_HOST} \
        "stat -c %s '${PVE_CFG_DST}/${ARCHIVE}'") bytes)"
else
    log "ERROR: pve-config tar failed"
fi

# 3. Prune old pve-config archives on pve1 (keep last KEEP_PVE_CONFIGS)
ssh ${SSH_OPTS} "root@${PVE1_HOST}" "
    cd '${PVE_CFG_DST}' && \
    ls -1t pve-config-*.tar.gz 2>/dev/null | tail -n +$((KEEP_PVE_CONFIGS + 1)) | xargs -r rm -v
" >>"$LOG" 2>&1 || true

log "=== Nightly mirror completed ==="