synchole/synchole.sh

#!/bin/bash

#
# synchole.sh
#

#  ****  configuration  ****

LISTS="whitelist.txt blacklist.txt regex.list" #pihole files to sync
LISTS_PATH="/etc/pihole" #pihole files path
MASTER="10.1.3.2" #IP or hostname of the MASTER server
DEBUG=1 #enable verbose output (1=on, 0=off)
BACKUP_PATH="/etc/pihole/synchole-backups" #path to backups
BACKUP_VERSIONS=10 #how many backups should be kept
TEMP_PATH="/tmp/synchole-downloads" #path to list downloads
DEPENDENCIES="wget"

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


#  ****  functions  ****

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

## check for local environment
amipihole() {
  if [ ! $(which pihole) ]; then
    return 1
  fi
}

## check if system is debian based
amidebian() {
  if [ ! $(which apt-get) ]; then
    return 1
  fi
}

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

  sleep 0.4; echo -e "[$NAME][$level] $2"
}

## update package sources
update_repos() {
  apt-get update > /dev/null
  if [ $? -ne 0 ]; then
    return 1
  fi
}

## install debian package
install_package() {
  if [ -n $1 ]; then
    apt-get install -y $1 &> /dev/null
    if [ $? -ne 0 ]; then
      return 1
    fi
  else
    return 1
  fi
}

## 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
}

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

log info "Commencing preflight checks."

## preflight checks
if ! amiroot; then
  log error "You must be root. Exiting."
  exit 1
else
  log debug "I am root. Continuing."
fi

if ! amidebian; then
  log error "I am no debian based system. Exiting."
  exit 1
else
  log debug "I am debian based. Continuing."
fi

if ! amipihole; then
  log error "I am no pihole. Exiting."
  exit 1 
else
  log debug "I am a pihole system. Continuing."
fi

for DEPENDENCY in $DEPENDENCIES; do
  if install_package $DEPENDENCY; then
    log debug "$DEPENDENCY successfully installed. Continuing."
  else
    log error "$DEPENDENCY could not be installed. Exiting."
    exit 1
  fi
done

log success "Preflight checks passed."

## generate $BACKUP_PATH and $TEMP_PATH if not available
if [ ! -d $BACKUP_PATH ]; then
  log info "$BACKUP_PATH does not exist. Creating."
  mkdir -p $BACKUP_PATH
  if [ $? -ne 0 ]; then
    log error "Something went wrong while creating $BACKUP_PATH. Exiting."
    exit 1
  fi
else
  log debug "$BACKUP_PATH exists. Continuing"
fi

if [ ! -d $TEMP_PATH ]; then
  log info "$BACKUP_PATH does not exist. Creating."
  mkdir -p $TEMP_PATH
  if [ $? -ne 0 ]; then
    log error "Something went wrong while creating $TEMP_PATH. Exiting."
    exit 1
  fi
else
  log debug "$TEMP_PATH exists. Continuing."
fi

## download remote files from MASTER and backup local lists
CHANGES=0
for LIST in $LISTS; do
  log info "Downloading $LIST."
  wget http://$MASTER/synchole/$LIST -q -O $TEMP_PATH/$LIST
  if [ $? -ne 0 ]; then
    log error "Something went wrong while downloading http://$MASTER/synchole/$LIST. Exiting."
    exit 1
  else
    log success "Successfully downloaded $LIST."
  fi

  diff $TEMP_PATH/$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."
    cp $TEMP_PATH/$LIST $LISTS_PATH/$LIST
    if [ $? -ne 0 ]; then
      log error "Something went wrong installing updated file to $LIST_PATH/$LIST"
    else
      log success "Successfully installed updated $LIST."
      CHANGES=1
    fi
  else
    log warn "No changes in $LIST. Skipping."
  fi
done

#run updateGravity
if [ $CHANGES -eq 1 ]; then
  pihole -g > /dev/null
  if [ $? -ne 0 ]; then
    log error "Something went wrong while updating Gravity. Exiting."
  else
    log success "Successfully updated Gravity."
  fi
else
  log warn "No files have been changed. Skipping Gravity update."
fi

#run restartdns (if hosts.list has been updated)

log success "Touchdown."
exit 0

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