From 16bf248308ec034817c3a2e74f6936a2fac80acb Mon Sep 17 00:00:00 2001
From: Stefan Ostermann <stefan@ostermail.de>
Date: Wed, 23 Jul 2025 14:04:24 +0000
Subject: [PATCH] backup script

---
 backup.sh | 107 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)
 create mode 100755 backup.sh

diff --git a/backup.sh b/backup.sh
new file mode 100755
index 0000000..405d7d8
--- /dev/null
+++ b/backup.sh
@@ -0,0 +1,107 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+shopt -s inherit_errexit nullglob
+
+# -----------------------------------------------------------------------------
+# CONFIGURATION — adjust to taste
+# -----------------------------------------------------------------------------
+readonly RETENTION_DAYS=7
+readonly BACKUP_BASE=/media/extension/backup/ubuntu
+readonly MOUNT_POINT=/media/extension
+
+# timestamp format — no spaces
+#readonly NOW=$(date +'%Y-%m-%d_%H-%M-%S')
+readonly NOW=$(date +'%Y-%m-%d')
+readonly THIS_RUN=${BACKUP_BASE}/${NOW}
+readonly LATEST=${BACKUP_BASE}/latest
+
+# directories (or files) to back up:
+declare -a SOURCE_ITEMS=(
+  "/home/oster/server"
+  "/home/oster/photo-lib"
+)
+
+# rsync exclusions — add your own
+declare -a EXCLUDES=(
+  --exclude='.cache'
+  --exclude='node_modules'
+  --exclude='*.tmp'
+)
+
+# rsync niceties
+RSYNC_OPTS=(
+  -aAXHv                # archive, preserve ACLs/xattrs, human-readable, verbose
+  --delete              # mirror deletions
+  --partial             # keep partials if interrupted
+  --stats               # give stats at end
+  "${EXCLUDES[@]}"
+)
+
+# Dry-run? set to "--dry-run" to test without writing
+DRY_RUN=""
+
+# -----------------------------------------------------------------------------
+# LOGGING & LOCKING / CLEANUP
+# -----------------------------------------------------------------------------
+log()   { echo "[$(date +'%F %T')] $*"; }
+die()   { log "FATAL: $*"; exit 1; }
+lockfile="${BACKUP_BASE}/.backup.lock"
+
+#trap 'rm -rf "$lockfile"' EXIT
+#if ! touch "$lockfile" 2>/dev/null; then
+#  die "Another backup is running (lockfile exists)."
+#fi
+
+# -----------------------------------------------------------------------------
+# FUNCTIONS
+# -----------------------------------------------------------------------------
+check_mount() {
+  if ! mountpoint -q "$MOUNT_POINT"; then
+    die "Backup mountpoint $MOUNT_POINT is not mounted."
+  fi
+}
+
+rotate_old() {
+  log "Rotating backups older than ${RETENTION_DAYS} days."
+  find "$BACKUP_BASE" -maxdepth 1 -mindepth 1 -type d \
+       ! -name 'latest' ! -name "$(basename "$THIS_RUN")" \
+       -mtime +${RETENTION_DAYS} \
+       -print -exec rm -rf {} \;
+}
+
+# -----------------------------------------------------------------------------
+# MAIN
+# -----------------------------------------------------------------------------
+log "=== Starting backup run: $NOW ==="
+check_mount
+
+mkdir -p "$BACKUP_BASE"
+mkdir -p "$THIS_RUN"
+
+# Determine if we can do a hardlink-incremental snapshot
+if [ -d "$LATEST" ]; then
+  LINK_DEST="--link-dest=$(readlink -f $LATEST)"
+  log "Using link‐dest for incremental snapshot → $LATEST"
+else
+  LINK_DEST=""
+  log "No previous backup; doing full snapshot."
+fi
+
+for src in "${SOURCE_ITEMS[@]}"; do
+  base=$(basename "$src")
+  dst="${THIS_RUN}/${base}"
+  log "Backing up $src → $dst"
+
+  nice -n 10 ionice -c2 -n7 \
+    rsync "${RSYNC_OPTS[@]}" $LINK_DEST $DRY_RUN \
+      "$src"/ "$dst"/
+done
+
+# update the "latest" symlink atomically
+tmp_latest="${BACKUP_BASE}/.latest.tmp"
+rm -f "$tmp_latest"
+ln -sfn "$(basename "$THIS_RUN")" "$tmp_latest"
+mv -T "$tmp_latest" "$LATEST"
+
+rotate_old
+log "=== Backup completed successfully ==="