rsync-time-backup/rsync_tmbackup.sh
2013-11-26 12:59:00 -08:00

279 lines
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#!/usr/bin/env bash
APPNAME=$(basename $0 | sed "s/\.sh$//")
# -----------------------------------------------------------------------------
# Log functions
# -----------------------------------------------------------------------------
fn_log_info() { echo "$APPNAME: $1"; }
fn_log_warn() { echo "$APPNAME: [WARNING] $1"; }
fn_log_error() { echo "$APPNAME: [ERROR] $1"; }
# -----------------------------------------------------------------------------
# Make sure everything really stops when CTRL+C is pressed
# -----------------------------------------------------------------------------
fn_terminate_script() {
fn_log_info "SIGINT caught."
exit 1
}
trap 'fn_terminate_script' SIGINT
# -----------------------------------------------------------------------------
# Small utility functions for reducing code duplication
# -----------------------------------------------------------------------------
fn_parse_date() {
# Converts YYYY-MM-DD-HHMMSS to YYYY-MM-DD HH:MM:SS and then to Unix Epoch.
case "$OSTYPE" in
linux*) date -d "${1:0:10} ${1:11:2}:${1:13:2}:${1:15:2}" +%s ;;
darwin*) date -j -f "%Y-%m-%d-%H%M%S" "$1" "+%s" ;;
esac
}
fn_find_backups() {
find "$DEST_FOLDER" -type d -name "????-??-??-??????" -prune | sort -r
}
fn_expire_backup() {
# Double-check that we're on a backup destination to be completely
# sure we're deleting the right folder
if [ -z "$(fn_find_backup_marker "$(dirname -- "$1")")" ]; then
fn_log_error "$1 is not on a backup destination - aborting."
exit 1
fi
fn_log_info "Expiring $1"
rm -rf -- "$1"
}
# -----------------------------------------------------------------------------
# Source and destination information
# -----------------------------------------------------------------------------
SRC_FOLDER=${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 "$1/backup.marker"; }
fn_find_backup_marker() { find "$(fn_backup_marker_path "$1")" 2>/dev/null; }
if [ -z "$(fn_find_backup_marker "$DEST_FOLDER")" ]; then
fn_log_info "Safety check failed - the destination does not appear to be a backup folder or drive (marker file not found)."
fn_log_info "If it is indeed a backup folder, you may add the marker file by running the following command:"
fn_log_info ""
fn_log_info "touch \"$(fn_backup_marker_path $DEST_FOLDER)\""
fn_log_info ""
exit 1
fi
# -----------------------------------------------------------------------------
# Setup additional variables
# -----------------------------------------------------------------------------
# Date logic
NOW=$(date +"%Y-%m-%d-%H%M%S")
EPOCH=$(date "+%s")
KEEP_ALL_DATE=$(($EPOCH - 86400)) # 1 day ago
KEEP_DAILIES_DATE=$(($EPOCH - 2678400)) # 31 days ago
export IFS=$'\n' # Better for handling spaces in filenames.
PROFILE_FOLDER="$HOME/.$APPNAME"
DEST=$DEST_FOLDER/$NOW
PREVIOUS_DEST=$(fn_find_backups | head -n 1)
INPROGRESS_FILE=$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."
mv -- "$PREVIOUS_DEST" "$DEST"
if [ "$(fn_find_backups | wc -l)" -gt 1 ]; then
PREVIOUS_DEST="$(fn_find_backups | sed -n '2p')"
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 "$PREVIOUS_DEST"; pwd)"
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
# -----------------------------------------------------------------------------
# Purge certain old backups before beginning new backup.
# -----------------------------------------------------------------------------
# Default value for $prev ensures that the most recent backup is never deleted.
prev="0000-00-00-000000"
for fname in $(fn_find_backups); do
date=$(basename "$fname")
stamp=$(fn_parse_date $date)
# Skip if failed to parse date...
[ -n "$stamp" ] || continue
if [ $stamp -ge $KEEP_ALL_DATE ]; then
true
elif [ $stamp -ge $KEEP_DAILIES_DATE ]; then
# Delete all but the most recent of each day.
[ "${date:0:10}" == "${prev:0:10}" ] && fn_expire_backup "$fname"
else
# Delete all but the most recent of each month.
[ "${date:0:7}" == "${prev:0:7}" ] && fn_expire_backup "$fname"
fi
prev=$date
done
# -----------------------------------------------------------------------------
# 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 $yn in
[Nn]* ) exit 0;;
esac
fn_log_warn "No space left on device - removing oldest backup and resuming."
BACKUP_FOLDER_COUNT=$(fn_find_backups | wc -l)
if [ "$BACKUP_FOLDER_COUNT" -lt "2" ]; then
fn_log_error "No space left on device, and no old backup to delete."
exit 1
fi
OLD_BACKUP_PATH=$(fn_find_backups | tail -n 1)
if [ "$OLD_BACKUP_PATH" == "" ]; then
fn_log_error "No space left on device, and cannot get path to oldest backup to delete."
exit 1
fi
fn_expire_backup "$OLD_BACKUP_PATH"
# Resume backup
continue
fi
if [ "$RSYNC_EXIT_CODE" != "0" ]; then
fn_log_error "Exited with error code $RSYNC_EXIT_CODE"
exit $RSYNC_EXIT_CODE
fi
# -----------------------------------------------------------------------------
# Add symlink to last successful backup
# -----------------------------------------------------------------------------
rm -rf -- "$DEST_FOLDER/latest"
ln -vs -- "$NOW" "$DEST_FOLDER/latest"
rm -- "$INPROGRESS_FILE"
# TODO: grep for "^rsync error:.*$" in log
fn_log_info "Backup completed without errors."
exit 0
done