href="https://pi-hole.net/">Pi-hole</a> adlist/blocklist, blacklist, whitelist, regex, custom DNS hostnames, and custom CNAME hostnames across multiple Pi-holes using a Git repository.
I was running six Pi-holes on three different networks at three different physical locations. I wanted all six Pi-holes to share the same adlists, blacklists, whitelists, and regex files, but it was time-consuming to manually synchronize all of them (modify the local Pi-holes, VPN into the second network and modify those, then VPN into the third network and modify those). I also wanted the ability to share custom DNS hostnames between multiple Pi-holes so that the Pi-hole UI stats display the proper local hostnames instead of IP addresses.
I wanted to use Pi-hole's built-in web UI to manage only *one* set of lists on *one* Pi-hole -- and then securely synchronize an unlimited number of additional Pi-holes. I couldn't find an existing script that did exactly what I wanted... so I wrote `pihole-cloudsync`.
`pihole-cloudsync` is lightweight enough to use if you're only syncing 2 Pi-holes on a home network, but powerful enough to synchronize virtually *unlimited* Pi-holes on an *unlimited* number of networks.
`pihole-cloudsync` allows you to designate any Pi-hole on any network to act as your "Master" or "Primary." This is the only Pi-hole whose list settings you will need to manage using Pi-hole's built-in web UI. The Primary Pi-hole then uses `pihole-cloudsync` in **Push** mode to *upload* four files to a private Git repository that you control (such as GitHub) that contain:
All other Secondary Pi-holes that you wish to keep synchronized use `pihole-cloudsync` in **Pull** mode to *download* the above files from from your private Git repository.
This script was originally written to work on Pi-hole version 4. However, as of Pi-hole version 5, most of the settings needed for sync between Pi-holes is no longer stored in individual text files -- they are now all stored in a single database file called `gravity.db`. The changes required to `pihole-cloudsync` to work with Pi-hole v5 means it will no longer with with version of Pi-hole earlier than v5.
**Before proceeding, verify that your Primary and *all* Secondary Pi-holes are running Pi-hole v5 or later.**
Prior to running `pihole-cloudsync`, you must first create a new dedicated Git repository to store your lists, then clone that new repository to all Pi-holes (both Primary and Secondary) that you wish to keep in sync. The easiest way to do that is to fork my <atarget="_blank"href="https://github.com/stevejenkins/my-pihole-lists">`my-pihole-lists`</a> GitHub repo as a **template**. Do not simply create a regular fork of my example repository. When you fork as a template instead, GitHub will allow you to set your new repository as "Private." Don't worry if the example lists in the example repo are different than yours. You'll overwrite your forked version of the repo with your own Pi-hole lists the first time you run `pihole-cloudsync` in **Push** mode.
4.*Optional:* If you wish to make your forked version of the repo private, press **Settings**, scroll down to the **Danger Zone**, then press **Make private**.
5. On your new repo's main page, press the **Clone or download** button and copy the **Clone with HTTPS** link to your clipboard.
4. Create your private local Git repo with `sudo git clone https://github.com/<yourusername>/my-pihole-lists.git` (paste the URL you copied from GitHub).
5. If you're using a repo name other than `my-pihole-lists`, edit `/usr/local/bin/pihole-cloudsync/pihole-cloudsync` and edit the `personal_git_dir` variable to match your local Git repo location.
6. Run `/usr/local/bin/pihole-cloudsync/pihole-cloudsync --initpush` to initialize the local Pi-hole in "Push" mode. It will grab your Primary Pi-hole's list files (both from the `gravity.db` database and `/etc/pihole`) and add them to your new local Git repo. The `--initpush` mode should only need to be run once on your Primary Pi-hole.
7. Run `/usr/local/bin/pihole-cloudsync/pihole-cloudsync --push` to push/upload your Primary Pi-hole's lists from your local Git repo to your remote Git repo. You will have to manually enter your GitHub email address and password the first time you do this, but read below for how to save your login credentials so you can run this script unattended.
4. Create your private local Git repo with `sudo git clone https://github.com/<yourusername>/my-pihole-lists.git` (paste the URL you copied from GitHub)
5. If you're using a repo name other than `my-pihole-lists`, edit `/usr/local/bin/pihole-cloudsync/pihole-cloudsync` and edit the `personal_git_dir` variable to match your local Git repo location.
6. Run `/usr/local/bin/pihole-cloudsync/pihole-cloudsync --initpull` to initialize the local Pi-hole in Pull/Download mode. You will have to manually enter your GitHub email address and password the first time you do this, but read below for how to save your login credentials so you can run this script unattended. The `--initpull` option will also perform your first pull automatically and only needs to be run once on each Secondary Pi-hole. All future pulls can be performed with `/usr/local/bin/pihole-cloudsync/pihole-cloudsync --pull`.
7. Running `pihole-cloudsync --pull` will pull/download your Primary Pi-hole's lists from your remote Git repo to your Secondary Pi-hole's local Git repo. The `--pull` option will automatically copy the downloaded file(s) to your Pi-hole directory and tell Pi-hole to do a `pihole -g` command to update its lists.
**The following steps must be performed on each Pi-hole you wish to use with `pihole-cloudsync`.**
In order to automate or run `pihole-cloudsync` unattended, you will need to either store your GitHub login credentials locally or create an SSH key for your Pi-hole's root user and upload the public key to GitHub. You will need to do this on the Primary Pi-hole as well as all Secondary Pi-holes.
The SSH key approach is for more advanced users who don't need me to explain how to do it. To store your Git credentials locally, do the following on each Pi-hole:
The next time you pull from or push to the remote repository, you'll be prompted for your username and password. But you won't have to re-enter them after that. So do a simple:
Once each Pi-hole's local Git repo has been configured to save your login credentials, you can automate your Primary Pi-hole's "push" and your Secondary Pi-holes' "pull" in any number of ways. The simplest method is to run a [cron job](#Automating-with-cron) a few times a day. If you want more flexibility over schedule and resource use, you can also use [systemd](#Automating-with-systemd) to automate. Both methods are explained below.
The simplest way is to automate `pihole-cloudsync` is to set a "push" cron job on your Primary Pi-hole that runs a few times a day, then set a "pull" cron job on each Secondary Pi-hole that pulls in any changes a few minutes after your Primary pushes them.
Once you can successfully run `pihole-cloudsync --push` from the command line on your Primary Pi-hole, do `crontab -e` (or `sudo crontab -e` if you're not logged in as the root user) and create a cron entry such as:
And once you can successfully run `pihole-cloudsync --pull` from the command line on each of your Secondary Pi-holes, do `sudo crontab -e` and create a cron entry that runs 5 minutes after your Primary pushes any changes, such as:
**NOTE:** On Raspian, the script won't execute via cron without the `sudo` command (as shown above). If you're having trouble getting the script to run unattended on Raspian, try including `sudo` in the cron command.
`pihole-cloudsync` pulls can also be automated with systemd, if your Pi-hole is running on a systemd-supported distro. Once you're able to successfully run `pihole-cloudsync --pull` from the command line on each of your Secondary Pi-holes, you can proceed with systemd setup. You must install three `[Unit]` files on your Pi-hole to ensure a stable and non-intrusive update process: a `.service` file, a `.timer` file, and a `.slice` file.
1.**.service** - `/etc/systemd/system/pihole-cloudsync-update.service` - The core service file. Configured as a 'oneshot' in order to be run via a [systemd timer](https://wiki.archlinux.org/index.php/Systemd/Timers).
2.**.timer** - `/etc/systemd/system/pihole-cloudsync-update.timer` - The timer file. Determines when the `.service` file is executed. systemd timers are highly flexible and can be executed under a variety of timed and trigger-based circumstances. The [ArchLinux systemd/Timer documentation](https://wiki.archlinux.org/index.php/Systemd/Timers) is some of the best around. See their [examples](https://wiki.archlinux.org/index.php/Systemd/Timers#Examples) for many more ways to configure this systemd timer unit.
3.**.slice** - `/etc/systemd/system/pihole-cloudsync-update.slice` - The slice file. Determines how much of the total system resources the `.service` is allowed to consume. This slice is in place to keep the update process in check and ensure that there will always be *plenty* of room for the Pi-hole service to answer DNS queries without being obstructed by potential `pihole-cloudsync` updates. If you'd like to learn more about systemd slices, check out [this wiki page](https://wikitech.wikimedia.org/wiki/Systemd_resource_control).
To upgrade to the latest version of `pihole-cloudsync`, do the following on *all* Primary and Secondary Pi-holes. Note that this will completely over-write any previous modifications you've made to `pihole-cloudsync`.
1. Do `cd /usr/local/bin/pihole-cloudsync`
2. Do `git fetch --all`
3. Do `git reset --hard origin/master`
Your local version of `pihole-cloudsync` is now updated to the lastest release version.
You are totally responsible for anything this script does to your system. Whether it launches a nice game of Tic Tac Toe or global thermonuclear war, you're on your own. :)
