Add daily backup scripts for PostgreSQL, MariaDB, and Gitea.

Enable scheduled backups of ncue.net databases and git.ncue.net repository mirrors via .env-driven shell scripts.

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/lib/common.sh

@@ -0,0 +1,66 @@
+#!/usr/bin/env bash
+# 백업 스크립트 공통 유틸
+
+log_ts() { date '+%Y-%m-%dT%H:%M:%S%z'; }
+
+# 오래된 YYYYMMDD 백업 디렉터리 삭제
+# 사용: prune_old_backups "$BACKUP_ROOT" "$RETENTION_DAYS"
+prune_old_backups() {
+  local backup_root="$1"
+  local retention_days="$2"
+  local cutoff removed=0 base day entry
+
+  [[ "$retention_days" =~ ^[0-9]+$ ]] || return 0
+  [[ "$retention_days" -le 0 ]] && return 0
+
+  if date -d "1 day ago" +%Y%m%d >/dev/null 2>&1; then
+    cutoff=$(date -d "${retention_days} days ago" +%Y%m%d)
+  else
+    cutoff=$(date -v-"${retention_days}"d +%Y%m%d)
+  fi
+
+  shopt -s nullglob
+  for entry in "$backup_root"/*; do
+    [[ -d "$entry" ]] || continue
+    base=$(basename "$entry")
+    [[ "$base" == "latest" ]] && continue
+    if [[ "$base" =~ ^([0-9]{8}) ]]; then
+      day="${BASH_REMATCH[1]}"
+      if [[ "$day" < "$cutoff" ]]; then
+        rm -rf "$entry"
+        removed=$((removed + 1))
+        echo "[$(log_ts)] retention: removed $entry (backup date $day < cutoff $cutoff)"
+      fi
+    fi
+  done
+  shopt -u nullglob
+  echo "[$(log_ts)] retention: pruned ${removed} dir(s); keeping backups from ${cutoff} onward (${retention_days} days)"
+}
+
+resolve_run_dir() {
+  local component="$1"
+  local stamp="${BACKUP_STAMP:-$(date +%Y%m%d)}"
+  local root="${BACKUP_DIR:-$REPO_ROOT/backup}"
+
+  if [[ -n "${BACKUP_RUN_DIR:-}" ]]; then
+    RUN_DIR="$BACKUP_RUN_DIR/$component"
+  else
+    RUN_DIR="$root/$stamp/$component"
+  fi
+  mkdir -p "$RUN_DIR"
+}
+
+update_latest_link() {
+  local component="$1"
+  local root="${BACKUP_DIR:-$REPO_ROOT/backup}"
+  local stamp="${BACKUP_STAMP:-$(date +%Y%m%d)}"
+  local target
+
+  if [[ -n "${BACKUP_RUN_DIR:-}" ]]; then
+    target="$BACKUP_RUN_DIR/$component"
+  else
+    target="$root/$stamp/$component"
+  fi
+
+  ln -sfn "$target" "$root/latest/$component"
+}