Added Pi-hole / cloudflared example for use of DoH

Signed-off-by: Leon Stoldt <tech@leon-stoldt.de>

README.md

@@ -34,6 +34,7 @@ application with Nginx proxy and a Mongo database.
 application with an Nginx proxy and a MySQL database.
 - [`NGINX / Go`](https://github.com/docker/awesome-compose/tree/master/nginx-golang) - Sample Nginx proxy with a Go backend.
 - [`NGINX / WSGI / Flask`](https://github.com/docker/awesome-compose/tree/master/nginx-wsgi-flask) - Sample Nginx reverse proxy with a Flask backend using WSGI.
+- [`Pi-hole / cloudflared`](https://github.com/docker/awesome-compose/tree/master/pihole-cloudflared-DoH) - Sample Pi-hole setup with use of DoH cloudflared service
 - [`React / Spring / MySQL`](https://github.com/docker/awesome-compose/tree/master/react-java-mysql) - Sample React
 application with a Spring backend and a MySQL database.
 - [`React / Express / MySQL`](https://github.com/docker/awesome-compose/tree/master/react-express-mysql) - Sample React

pihole-cloudflared-DoH/.env

@@ -0,0 +1,8 @@
+TIMEZONE=Etc/UTC
+PIHOLE_PW=changeit
+# Default values for CONDITIONAL_FORWARDING with AVM FRITZ!Box
+PIHOLE_ROUTER_IP=192.168.178.1
+PIHOLE_NETWORK_DOMAIN=fritz.box
+PIHOLE_REVERSE_DNS=192.168.178.0/24
+PIHOLE_HOST_IP=192.168.178.X
+PIHOLE_HOST_IPV6=

pihole-cloudflared-DoH/README.md

@@ -0,0 +1,108 @@
+## Pi-hole with cloudflared DoH (DNS-Over-HTTPS)
+This example provides a base setup for using [Pi-hole](https://docs.pi-hole.net/) with the [cloudflared DoH](https://docs.pi-hole.net/guides/dns/cloudflared/) service.
+More details on how to customize the installation and the compose file can be found in [Docker Pi-hole documentation](https://github.com/pi-hole/docker-pi-hole).
+
+
+Project structure:
+```
+.
+├── .env
+├── docker-compose.yaml
+└── README.md
+```
+
+[_docker-compose.yaml_](docker-compose.yaml)
+``` yaml
+services:
+  pihole:
+    image: pihole/pihole:latest
+    ports:
+      - "53:53/tcp"
+      - "53:53/udp"
+      - "67:67/udp"
+      - "8080:80/tcp"
+      - "8443:443/tcp"
+    ...
+  cloudflared:
+    image: visibilityspots/cloudflared
+    ports:
+      - "5054:5054/tcp"
+      - "5054:5054/udp"
+    ...
+```
+
+## Configuration
+
+### .env
+Before deploying this setup, you need to configure the following values in the [.env](.env) file.
+- TZ ([time zone](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones))
+- PIHOLE_PW (admin password)
+- PIHOLE_ROUTER_IP (only needed for activated conditional forwarding)
+- PIHOLE_NETWORK_DOMAIN (only needed for activated conditional forwarding)
+- PIHOLE_HOST_IP (IPv4 address of your Pi-hole - needs to by static)
+- PIHOLE_HOST_IPV6 (IPv6 address of your Pi-hole - can be empty if you only use IPv4)
+
+### Conditional forwarding (optional, default: enabled)
+If you would like to disable conditional forwarding, delete the environment variables starting with "CONDITIONAL_FORWARDING"
+
+### Container DNS (optional, default: disabled)
+In the docker-compose file, dns is added as a comment. To enable dns remove '#' in front of the following lines: 
+``` yaml
+dns:
+    - 127.0.0.1 # "Sets your container's resolve settings to localhost so it can resolve DHCP hostnames [...]" - github.com/pi-hole/docker-pi-hole
+    - 1.1.1.1 # Backup server 
+```
+
+## Deploy with docker-compose
+When deploying this setup, the admin web interface will be available on port 8080 (e.g. http://localhost:8080/admin).
+
+``` shell
+$ docker-compose up -d
+Starting cloudflared ... done
+Starting pihole      ... done
+```
+
+
+## Expected result
+
+Check containers are running and the port mapping:
+```
+$ docker ps
+CONTAINER ID   IMAGE                                 COMMAND                  CREATED         STATUS                            PORTS                                                                                                     NAMES
+afcf5ca4214c   pihole/pihole:latest                  "/s6-init"               3 seconds ago   Up 3 seconds (health: starting)   0.0.0.0:53->53/udp, 0.0.0.0:53->53/tcp, 0.0.0.0:67->67/udp, 0.0.0.0:8080->80/tcp, 0.0.0.0:8443->443/tcp   pihole
+dfd49ab7a372   visibilityspots/cloudflared           "/bin/sh -c '/usr/lo…"   4 seconds ago   Up 3 seconds (health: starting)   0.0.0.0:5054->5054/tcp, 0.0.0.0:5054->5054/udp                                                            cloudflared
+```
+
+Navigate to `http://localhost:8080` in your web browser to access the installed Pi-hole web interface.
+
+
+Stop the containers with
+``` shell
+$ docker-compose down
+# To delete all data run:
+$ docker-compose down -v
+```
+
+## Troubleshooting
+
+### - Starting / Stopping pihole-FTL loop:
+  Sometimes, it can happen that there occurs a problem starting pihole-FTL.
+  I personally had this issue when adding this line to the shared volumes:
+  ```
+  - "/pihole/pihole.log:/var/log/pihole.log"
+  ```
+  To fix this issue, I found this [issue](https://github.com/pi-hole/docker-pi-hole/issues/645#issuecomment-670809672), 
+  which suggested adding an empty file (`touch /pihole/pihole.log`) to prevent it from creating a directory.
+  The directory would not allow starting pihole-FTL and result in something like this:
+  ```
+  # Starting pihole-FTL (no-daemon) as root
+  # Stopping pihole-FTL
+  ...
+  ```
+  If you created an empty file, you may also check the ownership to prevent permission problems.
+  
+### - Installing on Ubuntu may conflict with `systemd-resolved` - see [Installing on Ubuntu](https://github.com/pi-hole/docker-pi-hole#installing-on-ubuntu) for help.
+
+### - Environment variables are version-dependent
+  Environment variables like "CONDIIONAL_FORWARDING*" and "DNS1" are deprecated and replaced by e.g. "REV_SERVER*" and "PIHOLE_DNS" in version 5.8+.
+  Current information about environment variables can be found here: https://github.com/pi-hole/docker-pi-hole

pihole-cloudflared-DoH/docker-compose.yaml

@@ -0,0 +1,55 @@
+version: '3.7'
+services:
+  cloudflared:
+    image: visibilityspots/cloudflared
+    container_name: cloudflared
+    ports:
+      - "5054:5054/tcp"
+      - "5054:5054/udp"
+    environment:
+      - TZ=${TIMEZONE}
+      - PORT=5054
+      - ADDRESS=0.0.0.0
+    restart: always
+    networks:
+      dns-net:
+        ipv4_address: 172.20.0.2
+
+  pihole:
+    container_name: pihole
+    image: pihole/pihole:latest
+    ports:
+      - "53:53/tcp"
+      - "53:53/udp"
+      - "67:67/udp"
+      - "8080:80/tcp"
+      - "8443:443/tcp"
+    environment:
+      - TZ=${TIMEZONE}
+      - PIHOLE_DNS_=172.20.0.2#5054;1.1.1.1 # referencing by name results in "Invalid IP detected in PIHOLE_DNS_: cloudflared#5054"
+      - WEBPASSWORD=${PIHOLE_PW}
+      - REV_SERVER=true
+      - REV_SERVER_TARGET=${PIHOLE_ROUTER_IP}
+      - REV_SERVER_DOMAIN=${PIHOLE_NETWORK_DOMAIN}
+      - REV_SERVER_CIDR=${PIHOLE_REVERSE_DNS}
+      - ServerIP=${PIHOLE_HOST_IP}
+      - ServerIPv6=${PIHOLE_HOST_IPV6}
+    #dns:
+      #- 127.0.0.1 # "Sets your container's resolve settings to localhost so it can resolve DHCP hostnames [...]" - github.com/pi-hole/docker-pi-hole
+      #- 1.1.1.1 # Backup server
+    volumes: # store your data between container upgrades
+      - "/etc/pihole/:/etc/pihole/"
+      - "/etc/dnsmasq.d/:/etc/dnsmasq.d/"
+    cap_add:
+      - NET_ADMIN # Recommended but not required (DHCP needs NET_ADMIN) https://github.com/pi-hole/docker-pi-hole#note-on-capabilities
+    depends_on:
+      - "cloudflared"
+    restart: always
+    networks:
+      - dns-net
+
+networks:
+  dns-net:
+    ipam:
+      config:
+        - subnet: 172.20.0.0/24