Pi-hole in Docker on a Synology NAS

Update	Date
New guide released	20/09/2021
Fixed a typo in the Environment Variables and added note around DHCP	25/11/2021

If you are looking to get advertising and tracking blocked across all the devices on your network a Pi-hole will have you covered.

Couple of things to note and common questions:

• Pi-hole is not able to block YouTube ads
• You will need to change the DNS settings either on your Router
• You will not be able to use this in conjunction with the DHCP server built into DSM as it uses the DNS port

In order for you to successfully use this guide please complete the the setting up a Docker user guide. Step 2: Setting up a restricted Docker user

Downloading the Pi-hole Image

Open up Docker within DSM and navigate to the ‘Registry’ tab and search for ‘PiHole’, in the list of available containers select the official image as shown below, right click on it and select ‘Download’ or click the button at the top of the window.

When asked choose ‘latest’ from the list of available versions

You can check the status of the download over on the ‘Image’ tab.

Setting up the container

In Docker click on the ‘Image’ tab, in the list of your containers select the ‘Pi-hole’ image and click on ‘Launch’

You will now see the initial setup screen, if you want to you can change the name of the container to something else, or if you are using a number of services on a machine with a limited amount of memory or lower powered CPU you can also setup resource limitations, but this is generally not required.

Next up we are going to click on the ‘Advanced Settings’ button, this will take you to a new window with a number of tabs which we are going to work through.

On the first tab enable ‘Auto Restart’ this will ensure Pi-hole will automatically start up whenever you reboot your NAS, keep in mind if you turn off your Diskstation you will lose internet access as there will be no way for devices to resolve DNS queries.

Volumes / Mounts

We can now move onto the volume tab in which we will be specifying the directories where Pi-hole will store its configuration files as per the table below.

File/Folder	Mount Path
/docker/pihole/dnsmasq.d	/etc/dnsmasq.d
/docker/pihole/pihole	/etc/pihole

We first click on ‘ Add folder’ so we can create some folders for the config files to live, first of all create one called ‘pihole’ inside your /docker share

Then within that folder create two new folders called ‘dnsmasq.d’ and ‘pihole’

Now you have created these folders select ‘dnsmasq.d’ and then type or copy ‘/etc/dnsmasq.d’ into the mount path.

Then click add folder again and this time select the ‘pihole’ sub-folder you created and then type ‘/etc/pihole’ into the mount path

You show now be setup exactly as below

Network

We are not going to be specifying specific ports for Pi-hole to use as it needs to use standard DNS ports, so tick the ‘Use the same network as Docker host’ check box

Links / Port Settings

You do not need to setup anything on these tabs.

Environment Variables (PGID,  PUID and Timezone)

Next we are going to setup a some environment variables that docker will use to allow the container access to our files and folders and also to tell it where we live in the world.

For each of the items in the table below you will need to click on ‘Add’ button then type each of the below in the ‘variable’ and ‘value’ sections

variable	Value
PGID	The UID you obtained in the user setup guide
PUID	The GID you obtained in the user setup guide
TZ	Your timezone wikipedia.org/wiki/List_of_tz_database_time_zones
WEBPASSWORD	A password of your choice for the Pi-hole web interface
DNSMASQ_LISTENING	local
WEB_PORT	8000

Once you have entered the above scroll down the Environment Variable as you will be able to see one called ServerIP you need enter the IP address of your NAS e.g 192.168.0.46

variable	Value
ServerIP	Enter the IP of you NAS

Almost done

You have now completed the container setup Click on the Apply button which will take you back to the screen we started at earlier, click on next and you should see the Summary screen giving you the overview of the settings we changed.

Click on Done and the container should now start up, give it 30 seconds or so and you should then be able to access the Pi-hole web interface via you NAS IP followed by port 8000

e.g. 192.168.0.46:8000

You will now need to add the IP address of your NAS as your DNS address in your router or other DHCP server. It can take some time for all of your devices to move over the the new DNS settings so be patient and you will gradually start to see your stats begin to start.

Also note as we are not using Pi-hole as the DHCP server you will not be able to see the names of the devices in the statistics just their IP addresses.

That’s it!

Throw me some bits or buy me a coffee?

If you have found my site useful please consider pinging me a tip as it helps cover the cost of running the site, you can even buy me a coffee 🙂