rsync-time-backup/rsync_tmbackup.sh
2013-11-12 11:14:02 +08:00

231 lines
7.4 KiB
Bash

#!/usr/bin/env bash
# -----------------------------------------------------------------------------
# Log functions
# -----------------------------------------------------------------------------
fn_log_info() {
echo "[RB INFO] $1"
}
fn_log_warn() {
echo "[RB WARN] $1"
}
fn_log_error() {
echo "[RB ERROR] $1"
}
# -----------------------------------------------------------------------------
# Make sure everything really stops when CTRL+C is pressed
# -----------------------------------------------------------------------------
fn_terminate_script() {
echo "SIGINT caught"
exit 1
}
trap 'fn_terminate_script' SIGINT
# -----------------------------------------------------------------------------
# Source and destination information
# -----------------------------------------------------------------------------
SRC_FOLDER=${1%/}
DEST_FOLDER=${2%/}
EXCLUSION_FILE=$3
# -----------------------------------------------------------------------------
# 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 $DEST_FOLDER)\""
fn_log_info ""
exit 1
fi
# -----------------------------------------------------------------------------
# Setup additional variables
# -----------------------------------------------------------------------------
BACKUP_FOLDER_PATTERN="\d\d\d\d-\d\d-\d\d-\d\d\d\d\d\d"
NOW=$(date +"%Y-%m-%d-%H%M%S")
PROFILE_FOLDER="$HOME/.rsync_tmbackup"
LOG_FILE="$PROFILE_FOLDER/$NOW.log"
DEST=$DEST_FOLDER/$NOW
LAST_TIME=$(ls -1 $DEST_FOLDER | grep "$BACKUP_FOLDER_PATTERN" | tail -n 1)
PREVIOUS_DEST=$DEST_FOLDER/$LAST_TIME
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 "$INPROGRESS_FILE" ]; then
if [ "$LAST_TIME" != "" ]; 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 "$INPROGRESS_FILE already exists - the previous backup failed or was interrupted. Backup will resume from there."
LINE_COUNT=$(ls -1 $DEST_FOLDER | grep "$BACKUP_FOLDER_PATTERN" | tail -n 2 | wc -l)
mv $PREVIOUS_DEST $DEST
if [ "$LINE_COUNT" -gt 1 ]; then
SECOND_LAST_TIME=$(ls -1 $DEST_FOLDER | grep "$BACKUP_FOLDER_PATTERN" | tail -n 2 | head -n 1)
LAST_TIME=$SECOND_LAST_TIME
else
LAST_TIME=""
fi
PREVIOUS_DEST=$DEST_FOLDER/$LAST_TIME
fi
fi
# Run in a loop to handle the "No space left on device" logic.
while [ "1" ]; do
# -----------------------------------------------------------------------------
# Check if we are doing an incremental backup (if previous backup exists) or not
# -----------------------------------------------------------------------------
LINK_DEST_OPTION=""
if [ "$LAST_TIME" == "" ]; 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
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
read -p "It looks like there is no space left on the destination. Delete old backup? (Y/n) " yn
case $yn in
[Nn]* ) exit 0;;
esac
fn_log_warn "No space left on device - removing oldest backup and resuming."
BACKUP_FOLDER_COUNT=$(ls -1 $DEST_FOLDER | grep "$BACKUP_FOLDER_PATTERN" | wc -l)
if [ "$BACKUP_FOLDER_COUNT" -lt "2" ]; then
fn_log_error "No space left on device, and no old backup to delete."
exit 1
fi
OLDEST_BACKUP=$(ls -1 $DEST_FOLDER | grep "$BACKUP_FOLDER_PATTERN" | head -n 1)
if [ "$OLDEST_BACKUP" == "" ]; then
fn_log_error "No space left on device, and cannot get path to oldest backup to delete."
exit 1
fi
OLD_BACKUP_PATH="$DEST_FOLDER/$OLDEST_BACKUP"
# Double-check that we're on a backup destination to be completely sure we're deleting the right folder
OLD_BACKUP_PARENT_PATH=$(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
rm $INPROGRESS_FILE
fn_log_info "Backup completed without errors."
exit 0
done