refined the script but it is still an early draft

README.md

@@ -6,6 +6,7 @@ Shell script to syncronize two or more [pi-hole](https://pi-hole.net) servers. I
 ## Setup
 
 1. Login via SSH to the `MASTER` server.
+
 2. Create symlinks for all files you want to sync within the webroot of the `MASTER` pihole.
 ```
 cd /var/www/html
@@ -14,29 +15,35 @@ cd synchole
 sudo ln -s /etc/pihole/whitelist.txt .
 sudo ln -s /etc/pihole/blacklist.txt .
 sudo ln -s /etc/pihole/regex.list .
-sudo ln -s /etc/hosts .
 ```
+
 3. Login via SSH to the `SLAVE` server.
+
 4. Install synchole on the `SLAVE` server.
 ```
 cd /opt
 sudo git clone https://socialg.it/david/synchole.git
 ```
+
 5. Configure the synchole script.
 ```
 sudo vim /opt/synchole.sh
 ```
 The config section is at the top of the script.
+
 6. Create a cron job for synchole on the `SLAVE` server.
 ```
 sudo crontab -e
 ```
 Example cronjob: `*/5 * * * * /opt/synchole/synchole.sh -q` (this runs the synchole every 5 minutes)
+
 7. Setup postfix to send notifications (from cron) on the `SLAVE` server.
 ```
 <placeholder>
 ```
-8. Repeat steps 3 through 5 for additional `SLAVE` servers.
+
+8. Repeat steps 3 through 7 for additional `SLAVE` servers.
+
 9. Happy syncholeing!
 
 

synchole.sh

@@ -5,17 +5,20 @@
 #
 
 #  ****  configuration  ****
+
 LISTS="whitelist.txt blacklist.txt regex.list" #pihole files to sync
 LISTS_PATH="/etc/pihole" #pihole files path
-HOSTS="hosts" #hosts file
-HOSTS_PATH="/etc" #hosts file path
-SYNC_HOSTS=1 #enable sync of the hosts file (1=on, 0=off)
 MASTER="10.1.3.2" #IP or hostname of the MASTER server
-DEPENDENCIES="wget"
 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
-TIMESTAMP=$(date +"%Y%m%d%H%M")
+DEPENDENCIES="wget"
+
+NAME="synchole"
+VERSION="0.1"
+AUTHOR="david@socialnerds.org"
+LICENSE="GPLv3"
 
 
 #  ****  functions  ****
@@ -46,23 +49,29 @@ log() {
   case $1 in
     "error")
       level="\033[31m✗\033[0m"
-      sleep 0.2; echo -e "[$level] $2"
       ;;
     "warn")
       level="\033[33m!\033[0m"
-      sleep 0.2; echo -e "[$level] $2"
       ;;
     "debug")
       if [ $DEBUG -eq 1 ]; then
 	level="\033[2md\033[0m"
-        sleep 0.2; echo -e "[$level] $2"
+      else
+	return 0
       fi
       ;;
-    *)
+    "success")
       level="\033[32m✓\033[0m"
-      sleep 0.2; echo -e "[$level] $*"
+      ;;
+    "info")
+      level=">"
+      ;;
+    *)
+      level="\033[31mLoglevel unknown. Programming error? ($*)\033[0m"
       ;;
   esac
+
+  sleep 0.4; echo -e "[$NAME][$level] $2"
 }
 
 ## update package sources
@@ -74,7 +83,7 @@ update_repos() {
 }
 
 ## install debian package
-install() {
+install_package() {
   if [ -n $1 ]; then
     apt-get install -y $1 &> /dev/null
     if [ $? -ne 0 ]; then
@@ -85,9 +94,35 @@ install() {
   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 "Mission takeoff!"
+log info "Commencing preflight checks."
 
 ## preflight checks
 if ! amiroot; then
@@ -111,11 +146,8 @@ else
   log debug "I am a pihole system. Continuing."
 fi
 
-log "Preflight checks passed."
-
-##installing missing dependencies
 for DEPENDENCY in $DEPENDENCIES; do
-  if install $DEPENDENCY; then
+  if install_package $DEPENDENCY; then
     log debug "$DEPENDENCY successfully installed. Continuing."
   else
     log error "$DEPENDENCY could not be installed. Exiting."
@@ -123,11 +155,11 @@ for DEPENDENCY in $DEPENDENCIES; do
   fi
 done
 
-log debug "All dependencies available. Continuing."
+log success "Preflight checks passed."
 
-#backup local and download remote files from MASTER
+## generate $BACKUP_PATH and $TEMP_PATH if not available
 if [ ! -d $BACKUP_PATH ]; then
-  log debug "$BACKUP_PATH does not exist. Creating."
+  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."
@@ -138,6 +170,7 @@ else
 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 $TEMP_PATH. Exiting."
@@ -147,35 +180,38 @@ else
   log debug "$TEMP_PATH exists. Continuing."
 fi
 
+## download remote files from MASTER and backup local lists
 CHANGES=0
 for LIST in $LISTS; do
-  if [ -r $LISTS_PATH/$LIST ]; then
+  log info "Downloading $LIST."
-    cp $LISTS_PATH/$LIST $BACKUP_PATH/$LIST\_$TIMESTAMP
-    if [ $? -ne 0 ]; then
-      log error "Something went wrong while backing up $LIST. Exiting."
-      exit 1
-    else
-      log "Successfully backed up $LIST."
-    fi
-  else
-    log warn "$LIST not found. Skipping."
-  fi
-
   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 "Successfully downloaded $LIST."
+    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 debug "Successfully installed updated $LIST. Continuing."
+      log success "Successfully installed updated $LIST."
       CHANGES=1
     fi
   else
@@ -189,16 +225,15 @@ if [ $CHANGES -eq 1 ]; then
   if [ $? -ne 0 ]; then
     log error "Something went wrong while updating Gravity. Exiting."
   else
-    log "Successfully updated Gravity."
+    log success "Successfully updated Gravity."
   fi
 else
   log warn "No files have been changed. Skipping Gravity update."
 fi
 
-#sync hosts
+#run restartdns (if hosts.list has been updated)
-#run restartdns (if hosts updates)
 
-log "Touchdown! Mission success."
+log success "Touchdown."
 exit 0
 
 #  ****  end of script  ****