I've struggled quite a bit to host pihole in a dokku container,
accessible over my LAN network and over the web through an allocated sub-domain name.

Due to no clear documentation for this being available on the web,
I've decided to write out some of my own after finally succeeding with my own setup.

Following prerequisites fall out of the scope of this installation guide:

• Git
• Docker
• Dokku
  • Linked domain name (e.g. my-dokku-server.com)
  • SSL Certification (e.g. LetsEncrypt, Cloudflare, ...)
• Ledokku (Optional)

(Yours will likely be different)

• 1.1. Move to your home directory and clone this repository with git:

  cd ~; git clone https://github.com/Rikj000/Pihole-Dokku-Installation.git

• 1.2. Copy the scripts to the right locations on the OS:

  sudo cp ~/Pihole-Dokku-Installation/scripts/enable-macvlan.sh /usr/bin/enable-macvlan
  sudo cp ~/Pihole-Dokku-Installation/scripts/enable-macvlan.service /lib/systemd/system/enable-macvlan.service

• 1.3. Setup the right permissions for the scripts:

  sudo chmod u+x /usr/bin/enable-macvlan
  sudo chmod 644 /lib/systemd/system/enable-macvlan.service

  Note: If your network setup differs, then you will need to modify /usr/bin/enable-macvlan

• 1.4. Start the enable-macvlan service + Enable it to auto-start on boot:

  sudo systemctl start enable-macvlan
  sudo systemctl enable enable-macvlan

• 1.5. Check virtual adapter status with ifconfig:

  ifconfig

  Output should be something like this:

  macvlan0  Link encap:Ethernet  HWaddr 92:8D:43:0E:E2:D8
  inet addr:192.168.0.210  Bcast:0.0.0.0  Mask:255.255.255.240
  inet6 addr: fe80::908d:43ff:fe0e:e2d8/64 Scope:Link
  UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
  RX packets:79 errors:0 dropped:0 overruns:0 frame:0
  TX packets:48 errors:0 dropped:0 overruns:0 carrier:0
  collisions:0 txqueuelen:1
  RX bytes:34863 (34.0 KiB)  TX bytes:16322 (15.9 KiB)

docker network create \
    --driver=macvlan \
    --gateway=192.168.0.1 \
    --subnet=192.168.0.0/24 \
    --ip-range=192.168.0.210/28 \
    -o parent=eth0 \
    macvlan-pihole

• 3.1. Create a pihole dokku app:
  (If using ledokku, then use GUI instead, to create the pihole app!)

  dokku apps:create pihole

• 3.2. Disable default --init process injection:

  dokku scheduler-docker-local:set pihole init-process false

• 3.3. Setup volumes to assure settings & storage will stick upon container re-creation:

  dokku storage:mount pihole ~/pihole-data/etc-pihole:/etc/pihole
  dokku storage:mount pihole ~/pihole-data/etc-dnsmasq.d:/etc/dnsmasq.d

• 3.4. Configure the required environment variables for the pihole,
  adjust TZ, ADMIN_EMAIL, VIRTUAL_HOST and CORS_HOSTS as needed:

  dokku config:set --no-restart pihole TZ='UTC'; \
  dokku config:set --no-restart pihole ADMIN_EMAIL='my-admin@email.com'; \
  dokku config:set --no-restart pihole REV_SERVER_TARGET='192.168.0.1'; \
  dokku config:set --no-restart pihole FTLCONF_LOCAL_IPV4='192.168.0.212'; \
  dokku config:set --no-restart pihole VIRTUAL_HOST='pihole.my-dokku-server.com'; \
  dokku config:set --no-restart pihole CORS_HOSTS='my-dokku-server.com,pihole.my-dokku-server.com,192.168.0.212'

• 3.5. Setup forwarding of the required ports for the pihole:

  dokku proxy:ports-add http:80:80 https:443:80 http:53:53 tcp:53:53 udp:53:53 udp:67:67

• 3.6. Setup the static pihole container IP as an additional domain-name for the app:

  dokku domains:add pihole 192.168.0.212

• 3.7. Setup additional deploy and run docker-options required for the pihole app:

  # Allow modification of network interfaces on the host system:
  dokku docker-options:add pihole deploy,run '--cap-add NET_ADMIN'
  
  # Set the static IP address for the pihole app:
  dokku docker-options:add pihole deploy,run '--ip "192.168.0.212"'
  
  # Set a static MAC address for the pihole app (Use this one, or a random other):
  dokku docker-options:add pihole deploy,run '--mac-address "02:42:c0:a8:01:d7"'

• 3.8. Make the pihole app directly accessible by other hosts on your network:

  dokku network:set pihole bind-all-interfaces true

• 3.9. Attach the pihole app to the macvlan-pihole network:

  dokku network:set pihole attach-post-create macvlan-pihole
  dokku network:set pihole attach-post-deploy macvlan-pihole
  dokku network:set pihole initial-network macvlan-pihole

• 3.10. Rebuild the network of the pihole app:

  dokku network:rebuild pihole

• 3.11. Deploy the latest pihole docker tag:

  dokku git:from-image pihole pihole/pihole:latest

dokku ps:stop pihole; docker pull pihole/pihole:latest; dokku ps:rebuild pihole

• Docs - Dokku
• Docs - Pihole
• Github - Docker-Pi-Hole
• Github Gist - Pihole-Macvlan-Synology-Docker
• Blog - Free your Synology ports for Docker
• Blog - Set up a PiHole using Docker MacVlan Networks
• Blog - Use systemd to Start a Linux Service at Boot