Pi-Hole Easy: Using Docker with Macvlan To Block Ads Without Taking Over Your Server

Pi-Hole is a fantastic ad-blocking software that can run on a Raspberry Pi or pretty much any other Linux or Windows machine. Most websites that can detect ad-blocking cannot detect Pi_hole and Pi-Hole protects your entire home network. It acts as a personal DNS server which can block advertising or other objectionable sites from your network using blacklists (similar to OpenDNS but completely configurable by you with unlimited whitelists and blacklists). Once it blocks the sites that are on its blacklist, it hands the DNS search off to a secondary DNS (either your ISP’s or one you designate such as Google’s or OpenDNS), thus providing you a second opportunity to filter.

There are may how-tos out there on how to install Pi-Hole, but this method provides the following advantages:

  • uses Docker to compartmentalize the installation from the rest of the files on your computer,
  • stores configuration files on your physical computer rather than in the container,
  • grants the Pi-Hole server a separate IP address from the physical computer you are running the container on (this allows you to install other services that would otherwise conflict with Pi-Hole as Pi-Hole tends to listen to all relevant ports).

This post and configuration is based on Tony Lawrence’s setup for synology. It uses the Macvlan network driver to provide the Pi-hole server an IP address separate from the physical computer on which the container is running.

Raspberry Pi Bug
Note that as of April, 2020, there is currently a bug with the latest 4.19v7 kernel of Raspbian which will prevent macvlan from working but there is a fix. See the note at the end of this post for more details. As far as I am aware this only has occurred on Raspbian and does not apply to other distros.

Installing

  1. Install Docker on a Linux computer (I use a Raspberry Pi).
  2. Install Docker-Compose.
  3. At the console enter the the following commands to download the docker-compose yaml file:
  4. Open the docker-compose.yaml file in your favorite text editor and edit as indicated by the #comments to add the IP address you want to assign to the Pi-hole container, as well as other network configurations:

  5. When done editing, save your changes and exit your editor.
  6. Copy files over from the image (this step should be done automatically by the volume attachment when the image is created by docker-compose but it did not work for me so I’m doing it manually here):
  7. Now start up the container:

    You can omit the second line if you don’t want to see the logs. If you keep it, when you see “Pi-hold blocking is enabled”, “Starting lighttpd” and “[services.d] done.]” the container is up and running:

    You can now can cancel out of the logs by hitting “Ctrl-C”.

  8. After a few minutes you will have Pi-Hole up and running. Type the IP4 address you revised on line #23 of the docker-compose.yaml file (e.g., 192.168.0.210), and you should see the following in your browser:

  9. If you click on the admin link you will see the following:

  10. Now login to your router, and edit your router settings so that the configured DNS matches the ip address on line #23.
    For example, on my router the configuration is as follows:

  11. It’s now up and running – blocking all ads to all of the computers, phones, tablets, and other devices in your home that are on your internal LAN or Wifi networks (obviously it won’t block cellular data).
  12. Read the documentation on the Pi-Hole website to configure the various options. The most common configuration changes will be to add certain sites to the whitelist (Pi-Hole has been known to block good web sites or server URL’s that are necessary for some functions like comments). You may also want to add blacklists other than the defaults.

    Shutting Down Pi-Hole

  13. Best to disable Pi-Hole in the web admin interface but if you really want to shut down the service type the following at the console:
    Keep in mind that wants this shuts down your network will no longer have a DNS service so your internet won’t work. Make sure you edit your router configuration to replace the Pi-Hole ip with the IP address of another DNS service (your ISP’s, Google’s, or OpenDnS for example).

    Updating Pi-Hole

  14. Updating Pi-Hole is easy when it is in a container. At the command line of your Linux server simply issue the following within the ~/docker/pihole directory:
  15. RASPBERRY PI BUG ALERT FOR MACVlAN: As I write this, there is currently an outstanding bug with the latest Raspbian 4.19.7 kernel published on 2-20-13 which prevents macvlan from working properly within a container on Raspbian PI (it does not expose its services to those outside its container). To fix, you can do a “sudo rpi-update” and reboot which will provide the bleeding edge update to the firmware and the kernel (currently updates kernel to 4.19.113-v7+). Do this only at your own risk! I did and the update to 4.19.113-v7+ went without a hitch and fixed the problem, but this update may cause other problems on your server as it’s an experimental update. The bug does not occur on earlier or later versions of the kernel.

2 Methods to Force Google Safe Search on DD-WRT All The Time for All Computers on Network

These two methods will enforce Google’s safesearch on all computers on your network (keep in mind that this won’t work for cell phones or other devices using cellular data). This is specific to any router using the DDWRT firmware. DDWRT is an open source firmware that is available to be flashed on a number of routers (check the DDWRT website for a list of compatible routers and installation details)

Method #1 – Rewrite DDWRT’s Hosts File on Startup

The simplest way to do this is to have your router edit your hosts file on each startup as follows:

  1. Go to Administration->Commands

  2. Click “Edit” and add the following script:

  3. Click “Run Commands”
  4. Click “Save Startup”
  5. Done!

What does this do ? It redirects those urls to the ip address of forcesafesearch.com. Your hosts file will be wiped out on every reboot of the router but the script will restore the settings.

While this is a very easy way of forcing safesearch, the disadvantage is that Google could change the ip address of safesearch. In addition, this method doesn’t permit wild cards.

Method #2 – Use DNSMasq

This method permits wildcards:

  1. Make sure that you have DNS masq enabled.
  2. Services->Additional DNSMasq option Box.
  3. Insert the following (Note the DOT before google.com, the dot acts as a wild card to pickup any subdomains):
  4. It should look like this:

  5. Click “Save” (button bottom of page)
  6. Click “Apply Settings”
  7. Done! If it doesn’t work right away you may need to reboot the router (use the button on the Services tab)