rsync-time-backup/rsync_tmbackup.sh
Laurent Cozic 2ade9de422 Fixed latest backup symlink issues
Code was in the wrong place (link being added when the backup failed only).
Also made the symlink relative to the current folder so that the drive
can be mounted with a different path.
2013-11-15 17:20:16 +08:00

246 lines
8.1 KiB
Bash

#!/usr/bin/env bash
# -----------------------------------------------------------------------------
# Log functions
# -----------------------------------------------------------------------------
fn_log_info() {
echo "rsync_tmbackup: $1"
}
fn_log_warn() {
echo "rsync_tmbackup: [WARNING] $1"
}
fn_log_error() {
echo "rsync_tmbackup: [ERROR] $1"
}
# -----------------------------------------------------------------------------
# Make sure everything really stops when CTRL+C is pressed
# -----------------------------------------------------------------------------
fn_terminate_script() {
echo "rsync_tmbackup: SIGINT caught."
exit 1
}
trap 'fn_terminate_script' SIGINT
# -----------------------------------------------------------------------------
# Source and destination information
# -----------------------------------------------------------------------------
SRC_FOLDER=${1%/}
DEST_FOLDER=${2%/}
EXCLUSION_FILE=$3
for arg in "$SRC_FOLDER" "$DEST_FOLDER" "$EXCLUSION_FILE"; do
if [[ "$arg" == *"'"* ]]; then
fn_log_error 'Arguments may not have any single quote characters.'
exit 1
fi
done
# -----------------------------------------------------------------------------
# Check that the destination drive is a backup drive
# -----------------------------------------------------------------------------
# TODO: check that the destination supports hard links
fn_backup_marker_path() {
echo "$1/backup.marker"
}
fn_is_backup_destination() {
DEST_MARKER_FILE="$(fn_backup_marker_path $1)"
if [ -f "$DEST_MARKER_FILE" ]; then
echo "1"
else
echo "0"
fi
}
if [ "$(fn_is_backup_destination $DEST_FOLDER)" != "1" ]; then
fn_log_info "Safety check failed - the destination does not appear to be a backup folder or drive (marker file not found)."
fn_log_info "If it is indeed a backup folder, you may add the marker file by running the following command:"
fn_log_info ""
fn_log_info "touch \"$(fn_backup_marker_path $DEST_FOLDER)\""
fn_log_info ""
exit 1
fi
# -----------------------------------------------------------------------------
# Setup additional variables
# -----------------------------------------------------------------------------
BACKUP_FOLDER_PATTERN=????-??-??-??????
NOW=$(date +"%Y-%m-%d-%H%M%S")
PROFILE_FOLDER="$HOME/.rsync_tmbackup"
LOG_FILE="$PROFILE_FOLDER/$NOW.log"
DEST=$DEST_FOLDER/$NOW
PREVIOUS_DEST=$(find "$DEST_FOLDER" -type d -name "$BACKUP_FOLDER_PATTERN" -prune | sort | tail -n 1)
INPROGRESS_FILE=$DEST_FOLDER/backup.inprogress
# -----------------------------------------------------------------------------
# Create profile folder if it doesn't exist
# -----------------------------------------------------------------------------
if [ ! -d "$PROFILE_FOLDER" ]; then
fn_log_info "Creating profile folder in '$PROFILE_FOLDER'..."
mkdir -- "$PROFILE_FOLDER"
fi
# -----------------------------------------------------------------------------
# Handle case where a previous backup failed or was interrupted.
# -----------------------------------------------------------------------------
if [ -f "$INPROGRESS_FILE" ]; then
if [ "$PREVIOUS_DEST" != "" ]; then
# - Last backup is moved to current backup folder so that it can be resumed.
# - 2nd to last backup becomes last backup.
fn_log_info "$INPROGRESS_FILE already exists - the previous backup failed or was interrupted. Backup will resume from there."
LINE_COUNT=$(find "$DEST_FOLDER" -type d -name "$BACKUP_FOLDER_PATTERN" -prune | sort | tail -n 2 | wc -l)
mv -- "$PREVIOUS_DEST" "$DEST"
if [ "$LINE_COUNT" -gt 1 ]; then
PREVIOUS_PREVIOUS_DEST=$(find "$DEST_FOLDER" -type d -name "$BACKUP_FOLDER_PATTERN" -prune | sort | tail -n 2 | head -n 1)
PREVIOUS_DEST=$PREVIOUS_PREVIOUS_DEST
else
PREVIOUS_DEST=""
fi
fi
fi
# Run in a loop to handle the "No space left on device" logic.
while [ "1" ]; do
# -----------------------------------------------------------------------------
# Check if we are doing an incremental backup (if previous backup exists) or not
# -----------------------------------------------------------------------------
LINK_DEST_OPTION=""
if [ "$PREVIOUS_DEST" == "" ]; then
fn_log_info "No previous backup - creating new one."
else
# If the path is relative, it needs to be relative to the destination. To keep
# it simple, just use an absolute path. See http://serverfault.com/a/210058/118679
PREVIOUS_DEST=`cd \`dirname -- "$PREVIOUS_DEST"\`; pwd`"/"`basename -- "$PREVIOUS_DEST"`
fn_log_info "Previous backup found - doing incremental backup from $PREVIOUS_DEST"
LINK_DEST_OPTION="--link-dest=$PREVIOUS_DEST"
fi
# -----------------------------------------------------------------------------
# Create destination folder if it doesn't already exists
# -----------------------------------------------------------------------------
if [ ! -d "$DEST" ]; then
fn_log_info "Creating destination $DEST"
mkdir -p -- "$DEST"
fi
# -----------------------------------------------------------------------------
# Start backup
# -----------------------------------------------------------------------------
LOG_FILE="$PROFILE_FOLDER/$(date +"%Y-%m-%d-%H%M%S").log"
fn_log_info "Starting backup..."
fn_log_info "From: $SRC_FOLDER"
fn_log_info "To: $DEST"
CMD="rsync"
CMD="$CMD --compress"
CMD="$CMD --numeric-ids"
CMD="$CMD --links"
CMD="$CMD --hard-links"
CMD="$CMD --delete"
CMD="$CMD --delete-excluded"
CMD="$CMD --one-file-system"
CMD="$CMD --archive"
CMD="$CMD --itemize-changes"
CMD="$CMD --verbose"
CMD="$CMD --log-file '$LOG_FILE'"
if [ "$EXCLUSION_FILE" != "" ]; then
# We've already checked that $EXCLUSION_FILE doesn't contain a single quote
CMD="$CMD --exclude-from '$EXCLUSION_FILE'"
fi
CMD="$CMD $LINK_DEST_OPTION"
CMD="$CMD -- '$SRC_FOLDER/' '$DEST/'"
CMD="$CMD | grep -E '^deleting|[^/]$'"
fn_log_info "Running command:"
fn_log_info "$CMD"
touch -- "$INPROGRESS_FILE"
eval $CMD
RSYNC_EXIT_CODE=$?
# -----------------------------------------------------------------------------
# Check if we ran out of space
# -----------------------------------------------------------------------------
# TODO: find better way to check for out of space condition without parsing log.
grep --quiet "No space left on device (28)" "$LOG_FILE"
NO_SPACE_LEFT="$?"
if [ "$NO_SPACE_LEFT" != "0" ]; then
# This error might also happen if there is no space left
grep --quiet "Result too large (34)" "$LOG_FILE"
NO_SPACE_LEFT="$?"
fi
rm -- "$LOG_FILE"
if [ "$NO_SPACE_LEFT" == "0" ]; then
# TODO: -y flag
read -p "It looks like there is no space left on the destination. Delete old backup? (Y/n) " yn
case $yn in
[Nn]* ) exit 0;;
esac
fn_log_warn "No space left on device - removing oldest backup and resuming."
BACKUP_FOLDER_COUNT=$(find "$DEST_FOLDER" -type d -name "$BACKUP_FOLDER_PATTERN" -prune | wc -l)
if [ "$BACKUP_FOLDER_COUNT" -lt "2" ]; then
fn_log_error "No space left on device, and no old backup to delete."
exit 1
fi
OLD_BACKUP_PATH=$(find "$DEST_FOLDER" -type d -name "$BACKUP_FOLDER_PATTERN" -prune | head -n 1)
if [ "$OLD_BACKUP_PATH" == "" ]; then
fn_log_error "No space left on device, and cannot get path to oldest backup to delete."
exit 1
fi
# Double-check that we're on a backup destination to be completely sure we're deleting the right folder
OLD_BACKUP_PARENT_PATH=$(dirname -- "$OLD_BACKUP_PATH")
if [ "$(fn_is_backup_destination $OLD_BACKUP_PARENT_PATH)" != "1" ]; then
fn_log_error "'$OLD_BACKUP_PATH' is not on a backup destination - aborting."
exit 1
fi
fn_log_info "Deleting '$OLD_BACKUP_PATH'..."
rm -rf -- "$OLD_BACKUP_PATH"
# Resume backup
continue
fi
if [ "$RSYNC_EXIT_CODE" != "0" ]; then
fn_log_error "Exited with error code $RSYNC_EXIT_CODE"
exit $RSYNC_EXIT_CODE
fi
# -----------------------------------------------------------------------------
# Add symlink to last successful backup
# -----------------------------------------------------------------------------
cd "$DEST_FOLDER"
rm -f -- "latest"
ln -s -- $(basename -- "$DEST") "latest"
cd -
rm -- "$INPROGRESS_FILE"
# TODO: grep for "^rsync error:.*$" in log
fn_log_info "Backup completed without errors."
exit 0
done