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--- backup_script [2025/04/24 18:57] – -Condense, grammar, bullet prerequisites hogwild
+++ backup_script [2025/09/10 15:45] (current) – Key issue fixec thilo
@@ Line 1: / Line 1: @@
 ====== Backup Script ======
-Let's say you wanted to schedule a backup done via a cron job. Let's assume you want that script initiated from, and stored in a safe location on a server on the network, (not on the router).
+==== Goals ====
-Further, you do not wish to install SFTP just for these backups.
+ \\
-The following script will download the script without needing to have SFTP enabled on the router.
+  - You want to schedule a backup to be done via a cron job.
+  - You want the script initiated from, and stored in a safe location  \\ on a server on the network (not on the router).
+  - You do not wish to install SFTP just for these backups.
  \\
-One option would be to create the backup as a cron job on the router itself. However, let's assume you want to have it all done in just one run. For this reason, creation of the backup in an individual file with timestamp was included in the script.
+The script at the bottom of this page will create and download the backup without needing to have SFTP enabled on the router.
-In this way, just one run of the script on the backup server would create the backup and download it to to a safe location.
+You could, of course, create the backup as a cron job on the router itself, and then use the mechanism applied in the script below to download the backup file. However, let's assume you want everything done in just one run of the script. To achieve this, the script covers creation of the backup in an individual file with timestamp and download.
-Action is based on using a here doc to execute commands on the router.
+In this way, just one run of the script on the backup server will create the backup and download it to to a safe location.
-The backup is created by using the "//nvram save//" command. This is how backups are done in the web interface. You may cross-check (what? at the command line?) by using "//nvram convert//" command.
+ \\ \\ The backup is created using the "//nvram save//" command. This is how backups are done "under the hood" in the web interface.
-The script then archives the resulting data in a tar file and sends it through the netcat command.
+You may cross-check that the backups are identical to the ones via the GUI using the following steps (last tested at 2025-04-22):
  \\
-Prerequisites:
+  - Download the backup via the graphical interface
+  - Create a backup via a script
+  - Copy both files to router
+  - Convert both files via the command: \\  ''"nvram convert <filename1/2>  > result_file1/2.txt"''
+  - Perform a diff between the two resulting text files.
  \\
-  - The netcat command must be available on the backup server
+The script then archives the resulting data in a tar file and sends it through the netcat command, transferring it over the network. Restore a backup file uses the same procedure as restoring an archive created in the web interface. This was last tested on 2025-04-29.
-  - The SSH key of of the executing user from backup server must be available to the router's root user.
+ \\
+==== Prerequisites ====
+ \\
+  - The netcat command must be available on the backup server.
+  - The user executing the script on backup server must have access to the router's root user via SSH key.
+ \\
+==== Remarks ====
+ \\
+  - Command line arguments: backup directory, id-file and router (as IP address). \\ If provided, these will be used. Otherwise, the defaults will apply \\ (search Router IP from "ip r").
+  - Sometimes tar may fail. You can solve this by just cleaning. The next \\ cron run may do that.
+  - All earlier backups from the same day are abandoned.
+  - A total number of backups is kept. This number is configurable. \\ Older backups are deleted.
  \\
@@ Line 32: / Line 58: @@
    #!/bin/bash
-   USER=root
+   DATE_REGEX=20[0-9][0-9][01][0-9][0123][0-9]
+   TIME_REGEX=[012][0-9][0-5][0-9]
+   NO_OF_DIFF_FILES_TO_BE_KEPT=10
+   DIR2BACKUP=/home/${LOGNAME}/Router_Backups
    LOCAL_ID_FILE=/home/${LOGNAME}/.ssh/id_tomato_ecdsa
+   ROUTER=`ip r | grep default | head -1 | cut -d " " -f 3`
+   while [[ $# -gt 0 ]]; do
+        case $1 in
+                -d|--dir2backup)
+                        DIR2BACKUP=$2 ;;
+                -i|--idfile)
+                        LOCAL_ID_FILE=$2 ;;
+                -r|--router)
+                        ROUTER=$2 ;;
+                -*|--*)
+                        echo "Unknown option $1" ;;
+                -h|--help)
+                        echo "usage $0 <option argument>
+                        echo "options are:"
+                        echo "  -d \| --dir2backup      directory to save backup,               default: ${DIR2BACKUP} "
+                        echo "  -r \| --router          router ostname or IP to be saved,       default: ${ROUTER}"
+                        echo "  -i \| --idfile          directory to save backuip,              default: ${ROUTER}
+                        exit ;;
+        esac
+        shift; shift
+   done
+   BACKUPHOST=`ip r | grep "${ROUTER%1}0/24" | head -1 | cut -d " " -f 9`
+   echo
+   echo "Backup dir:  "${DIR2BACKUP}
+   echo "id file:     "${LOCAL_ID_FILE}
+   echo "Backing up:  "${ROUTER}
+   echo "Backup host: "${BACKUPHOST}
+   echo
+   USER=root
    PORT=5555
-   BACKUP_DIR=/home/${LOGNAME}/Router_Backups
    SCRIPT_FILE=nvram_save_cfg.sh
    PREFIX=FreshTomato
-   EXT=.cfg
+   EXT=cfg
    TRANSFER_FILENAME=config.tar
-   ROUTER=`ip r | grep default | head -1 | cut -d " " -f 3`
+   # It may happen, that Tomato router has no - or other, wrong - time
-   pushd ${BACKUP_DIR}
+   # take date from localhost (i.e. backup server) into backup filename
+   DATE=`date +%Y%m%d_%H%M`
-   (netcat -l -p ${PORT} > ${TRANSFER_FILENAME}) &
+   pushd ${DIR2BACKUP} > /dev/null
+   rm -f ${TRANSFER_FILENAME}
    #
    # Thinks like
    # VAR=`nvram get os_version`
-   # seem not to work in bash via here doc, so write results into script file and source it
+   # seem not to work in bash via here doc, so write results into script file and source it.
-   # Further the individual filename is general not known, so tar it into temp file
+   # Further the individual filename is generally not known, so tar it into temp file.
    #
-   ssh ${USER}@${ROUTER} -i ${LOCAL_ID_FILE}<<ENDSSH
+   # Kill netcat zombies
-           rm -f ${SCRIPT_FILE} ${TRANSFER_FILENAME} ${PREFIX}_*_20[234][0-9][01][0-9][0123][0-9]_[012][0-9][0-5][0-9]${EXT}
+   kill -9 `ps -ef | grep -v grep | grep netcat | sed -e "s/ [ ]*/ /g" | cut -d " " -f 2` 2> /dev/null
-           echo "nvram save ${PREFIX}" >> ${SCRIPT_FILE}
+   (netcat -l -p ${PORT} > ${TRANSFER_FILENAME}) &
-           nvram get os_version | sed -e "s/ .*$//" >> ${SCRIPT_FILE}
+   # Create the backup file on the router by executing the following commands (indented lines) there
-           echo "on" >> ${SCRIPT_FILE}
+   ssh ${USER}@${ROUTER} -i ${LOCAL_ID_FILE} <<ENDSSH
-           nvram get t_model_name | tr " " "_" >> ${SCRIPT_FILE}
+        rm -f ${SCRIPT_FILE} ${TRANSFER_FILENAME} ${PREFIX}_*_${DATE_REGEX}_${TIME_REGEX}.${EXT}
-           nvram get router_name >> ${SCRIPT_FILE}
+        echo "nvram save ${PREFIX}" >> ${SCRIPT_FILE}
-           date +%Y%m%d_%H%M >> ${SCRIPT_FILE}
+        nvram get os_version | sed -e "s/ .*$//" >> ${SCRIPT_FILE}
-           sed -e "N;N;N;N;N;s/\n/_/g;s/$/${EXT}/" -i ${SCRIPT_FILE}
+        echo "on" >> ${SCRIPT_FILE}
-           cat ${SCRIPT_FILE}
+        nvram get t_model_name | tr " " "_" >> ${SCRIPT_FILE}
-           source ${SCRIPT_FILE}
+        nvram get router_name >> ${SCRIPT_FILE}
-           tar -cvf ${TRANSFER_FILENAME} *_20[234][0-9][01][0-9][0123][0-9]_[012][0-9][0-5][0-9]${EXT}
+        echo ${DATE} >> ${SCRIPT_FILE}
-           cat ${TRANSFER_FILENAME} | nc caisfiles ${PORT}
+        sed -e "N;N;N;N;N;s/\n/_/g;s/$/.${EXT}/" -i ${SCRIPT_FILE}
-           rm -f ${SCRIPT_FILE} ${TRANSFER_FILENAME} ${PREFIX}_*_20[234][0-9][01][0-9][0123][0-9]_[012][0-9][0-5][0-9]${EXT}
+        source ${SCRIPT_FILE}
+        tar -cvf ${TRANSFER_FILENAME} ${PREFIX}_*_${DATE_REGEX}_${TIME_REGEX}.${EXT} > /dev/null
+        cat ${TRANSFER_FILENAME} | nc ${BACKUPHOST} ${PORT}
+        sleep 5 # just wait a little while before deleting the files not needed here any more
+        rm -f ${SCRIPT_FILE} ${TRANSFER_FILENAME} ${PREFIX}_*_${DATE_REGEX}_${TIME_REGEX}.${EXT}
    ENDSSH
-   tar -xvf ${TRANSFER_FILENAME}
+   THIS_BACKUP_FILE=`tar -xvf ${TRANSFER_FILENAME} | sed -e "s/^.*${PREFIX}/${PREFIX}/"`
-   rm ${TRANSFER_FILENAME}
+   if [ "${THIS_BACKUP_FILE}" ]; then
-   popd
+        echo "Saved on this computer in `pwd`:"
+        echo ${THIS_BACKUP_FILE}
+        echo
+        TODAYS_BACKUP_FILES_PREFIX=${THIS_BACKUP_FILE%_*}
+        ALL_BACKUP_FILES_PREFIX=${TODAYS_BACKUP_FILES_PREFIX%_*}
+        # Keep only one file (the latest) per day - delete earlier file of same day
+        LIST_OLD_BACKUPS_OF_TODAY=`ls ${TODAYS_BACKUP_FILES_PREFIX}_${TIME_REGEX}.${EXT} 2> /dev/null | grep -v ${THIS_BACKUP_FILE}`
+        if [ "${LIST_OLD_BACKUPS_OF_TODAY}" ]; then
+                echo "deleting earlier backups from today (to keep just one per day - the most recent):"
+                rm -fv ${LIST_OLD_BACKUPS_OF_TODAY}
+                echo
+        fi
+        # In total, keep only ${NO_OF_DIFF_FILES_TO_BE_KEPT} files - delete older files (of any day)
+        OLDER_FILES=`ls ${ALL_BACKUP_FILES_PREFIX}_${DATE_REGEX}_${TIME_REGEX}.${EXT} | sort -r | sed -e 1,${NO_OF_DIFF_FILES_TO_BE_KEPT}d`
+        if [ "${OLDER_FILES}" ]; then
+                echo "keep only ${NO_OF_DIFF_FILES_TO_BE_KEPT} in total, delete:"
+                rm -fv ${OLDER_FILES}
+                echo
+        fi
+        # delete transfer file only when tar was successful, i.e. only here
+        rm ${TRANSFER_FILENAME}
+   else
+        echo "unknown error while untaring"
+   fi
+   popd > /dev/null
  \\

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