synchole/synchole.sh

#!/bin/bash

#
# synchole.sh
# Pi-Hole syncronizer
#

#  ****  configuration  ****

MASTER="10.1.3.2" #IP or hostname of the MASTER server
DEBUG=1 #enable verbose output (1=on, 0=off)
BACKUP_VERSIONS=10 #how many backups should be kept
BACKUP_PATH="/etc/pihole/synchole-backups" #path to backups
DOWNLOAD_PATH="/tmp/synchole-downloads" #path to list downloads

LISTS="whitelist.txt blacklist.txt regex.list" #pihole files to sync
LISTS_PATH="/etc/pihole" #pihole files path

NAME="synchole"
VERSION="0.1"
AUTHOR="david@socialnerds.org"
LICENSE="GPLv3"
DEPENDENCIES="wget"


#  ****  functions  ****

## check for elevated privileges
amiroot() {
  if [ $(whoami) != "root" ]; then
    return 1
  fi
}

## check if pi-hole is installed
amipihole() {
  if [ ! $(which pihole) ]; then
    return 1
  fi
}

## output handling
log() {
  case $1 in
    "error")
      level="\033[31m✗\033[0m"
      ;;
    "warn")
      level="\033[33m!\033[0m"
      ;;
    "debug")
      if [ $DEBUG -eq 1 ]; then
	      level="\033[2md\033[0m"
      else
	      return 0
      fi
      ;;
    "success")
      level="\033[32m✓\033[0m"
      ;;
    "info")
      level="i"
      ;;
    *)
      level="\033[31mLoglevel unknown. Programming error? ($*)\033[0m"
      ;;
  esac

  sleep 0.5; echo -e "[$level] $2"
}

## backup single list file to $BACKUP_PATH
backup_list() {
  if [ -z $1 ]; then
    return 1
  else
    for VERSION in $(eval echo {$BACKUP_VERSIONS..1}); do
      if [ -w $BACKUP_PATH/$1.$VERSION ]; then
      	if [ $VERSION -eq $BACKUP_VERSIONS ]; then
      	  rm $BACKUP_PATH/$1.$VERSION
      	else
      	  mv $BACKUP_PATH/$1.$VERSION $BACKUP_PATH/$1.$(($VERSION+1))
      	fi
      fi
    done
    if [ -w $BACKUP_PATH/$1 ]; then
      cp $BACKUP_PATH/$1 $BACKUP_PATH/$1.1
    fi
    if [ -r $LISTS_PATH/$1 ]; then
      cp $LISTS_PATH/$1 $BACKUP_PATH/$1
      if [ $? -ne 0 ]; then
        return 1
      fi
    fi
  fi
}

## create path/to/folder if it does not exist
create_path() {
  if [ -z $1 ]; then
    return 1
  else
    if [ ! -d $1 ]; then
      mkdir -p $1
      if [ $? -ne 0 ]; then
        return 1
      fi
    fi
  fi
}

## update pi-hole lists (run updateGravity)
update_gravity() {
  pihole -g > /dev/null
  if [ $? -ne 0 ]; then
    return 1
  fi
}

## install new list
install_list() {
  if [ -z $1 ]; then
    return 1
  else
    cp $DOWNLOAD_PATH/$1 $LISTS_PATH/$1
    if [ $? -ne 0 ]; then
      return 1
    fi
  fi
}

## download remote file
download_list() {
  if [ -z $1 ]; then
    return 1
  else
    wget http://$MASTER/synchole/$1 -q -O $DOWNLOAD_PATH/$1
    if [ $? -ne 0 ]; then
      return 1
    fi
  fi
}

#  ****  start of script  ****

## preflight checks
if ! amiroot; then
  log error "You must be root"
  exit 1
fi

if ! amipihole; then
  log error "I am no pihole"
  exit 1
fi

for DEPENDENCY in $DEPENDENCIES; do
  if ! $(which $DEPENDENCY); then
    log error "$DEPENDENCY is not installed"
    exit 1
  fi
done

log success "Preflight checks passed"

## generate $BACKUP_PATH and $DOWNLOAD_PATH if not available
if ! create_path $DOWNLOAD_PATH; then
  log error "Something went wrong while creating $DOWNLOAD_PATH"
  exit 1
fi

if ! create_path $BACKUP_PATH; then
  log error "Something went wrong while creating $BACKUP_PATH"
  exit 1
fi

## download remote files from MASTER and backup local lists
CHANGES=0
for LIST in $LISTS; do
  log info "Downloading $LIST."
  if ! download_list $LIST; then
    log error "Something went wrong while downloading $LIST"
    exit 1
  else
    log success "Successfully downloaded $LIST."
  fi

  #TODO: don't install new list if to many changes or
  #      somehow verify if new file is an actual list
  #      maybe check if wget actually downloaded a file or were we redirected
  diff $DOWNLOAD_PATH/$LIST $LISTS_PATH/$LIST
  if [ $? -ne 0 ]; then
    log info "Backing up $LIST."
    if [ -r $LISTS_PATH/$LIST ]; then
      if ! backup_list $LIST; then
        log error "Something went wrong while backing up $LIST. Exiting."
        exit 1
      else
        log success "Successfully backed up $LIST."
      fi
    else
      log warn "$LIST not found. Skipping."
    fi

    log info "Installing $LIST."
    if ! install_list $LIST; then
      log error "Something went wrong while installing $LIST"
    else
      log success "Successfully installed $LIST"
      CHANGES=1
    fi
  else
    log debug "No changes in $LIST"
  fi
done

## run updateGravity
if [ $CHANGES -eq 1 ]; then
  if update_gravity; then
    log error "Something went wrong while updating gravity"
  else
    log success "Gravity has been successfully updated"
  fi
else
  log debug "No files have been changed, skipping gravity update"
fi

exit 0

#  ****  end of script  ****