iotstack_backup_influxdb

#!/bin/bash

# should not run as root
[ "$EUID" -eq 0 ] && echo "This script should NOT be run using sudo" && exit -1

# support user renaming of script
SCRIPT=$(basename "$0")

# the default name and correct extension type is
DEFAULTFILENAME="influx-backup.tar"

# $1 is required and is either path to a .tar or the path to a folder
# $2 is optional and is the runtag (yyyy-mm-dd_hhmm.host-name)
# $3 is optional and overrides the default file name

case "$#" in

  1)
    BACKUP_TAR=$(realpath "$1")
    ;;

  2 | 3)
    BACKUP_TAR=$(realpath "$1/$2.${3:-"$DEFAULTFILENAME"}")
    ;;

  *)
    echo "Usage 1: $SCRIPT path/to/$DEFAULTFILENAME"
    echo "Usage 2: $SCRIPT path/to/backupdir runtag {override}"
    echo "         (override defaults to $DEFAULTFILENAME)"
    exit -1
    ;;

esac

# fail safe if the file already exists - no accidental overwrites
if [ -e "$BACKUP_TAR" ] ; then
   echo "Error: $BACKUP_TAR already exists - will not be overwritten"
   exit -1
fi

# assumptions
IOTSTACK="$HOME/IOTstack"
BACKUPS="$IOTSTACK/backups"
INFLUXBACKUP="$BACKUPS/influxdb"
INFLUXBACKUPDB="$INFLUXBACKUP/db"

# is influxdb running?
if [ $(docker ps | grep -c "influxdb") -eq 0 ]; then
   echo "Warning: influxdb container not running - backup skipped"
   exit 0
fi

# make sure the backups directory exists & has correct ownership & mode
[ -d "$BACKUPS" ] || mkdir -m 755 -p "$BACKUPS"
[ $(stat -c "%U:%G" "$BACKUPS") = "$USER:$USER" ] || sudo chown $USER:$USER "$BACKUPS"
[ $(stat -c "%a" "$BACKUPS") = "755" ] || sudo chmod 755 "$BACKUPS"

# make sure the influx backup directory exists & has correct ownership & mode
[ -d "$INFLUXBACKUPDB" ] || sudo mkdir -m 755 -p "$INFLUXBACKUPDB"
[ $(stat -c "%U:%G" "$INFLUXBACKUP") = "root:root" ] || sudo chown -R root:root "$INFLUXBACKUP"
[ $(stat -c "%a" "$INFLUXBACKUP") = "755" ] || sudo chmod -R 755 "$INFLUXBACKUP"

# now we can begin
echo "----- Starting $SCRIPT at $(date) -----"

# create the file (sets ownership)
touch "$BACKUP_TAR"

# the influx backup directory needs to be empty
if [ $(ls -1 "$INFLUXBACKUPDB" | wc -l) -gt 0 ] ; then
   echo "Erasing $INFLUXBACKUPDB"
   sudo rm "$INFLUXBACKUPDB"/*
fi

# tell influx to perform the backup
echo "Telling influxd to create a portable backup"
docker exec influxdb influxd backup -portable /var/lib/influxdb/backup

# sweep the backup into a tar (sudo is needed because backup files are
# created with owner root, group root, mode 600)
echo "Collecting the backup files into a tar"
sudo tar \
	-cf "$BACKUP_TAR" \
	-C "$INFLUXBACKUPDB" \
	.

# report size of archive
du -h "$BACKUP_TAR"

echo "----- Finished $SCRIPT at $(date) -----"