Have just spent the last three and a half hours tearing my hair out trying to make this work. Am migrating from v5.
If I leave the default ports alone, trying to hit the url times out. If I change the port of Pihole via a FTLCONF_webserver_port Traefik cannot see Pihole and exposing the changed port does nothing – as in it doesn't appear as exposed when running docker ps -a.
I'm at a loss as to where to go here, other than to revert back to v5.
Docker compose snippet:
pihole:
image: pihole/pihole:latest
container_name: pihole
hostname: pihole
networks:
network_name:
ipv4_address: 10.5.0.3
dns:
- 127.0.0.1
- 1.1.1.1
ports:
- 53:53/tcp
- 53:53/udp
environment:
TZ: Cont/City
FTLCONF_dns_listeningMode: all
FTLCONF_dns_upstreams: 10.5.0.4#5053
FTLCONF_webserver_domain: "pihole.domain.com"
FTLCONF_webserver_interface_theme: default-auto
FTLCONF_webserver_interface_boxed: false
volumes:
- "./pihole/etc-pihole:/etc/pihole"
- "./pihole/etc-dnsmasq.d:/etc/dnsmasq.d"
cap_add:
- NET_ADMIN
depends_on:
- cloudflared
labels:
- "traefik.enable=true"
- "traefik.http.routers.pihole.tls=true"
- "traefik.http.routers.pihole.rule=Host(`pihole.domain.com`)"
- "traefik.http.middlewares.pihole-redirect.redirectregex.regex=^https://pihole.domain.com/?$$"
- "traefik.http.middlewares.pihole-redirect.redirectregex.replacement=https://pihole.domain.com/admin"
restart: unless-stopped
Please share the output of:
docker ps
docker image ls pihole/pihole
Thanks for the quick reply.
Output of docker compose ps -a:
NAME COMMAND SERVICE STATUS PORTS
cloudflared "/usr/local/bin/clou…" cloudflared running (healthy) 49312/tcp
dhcp-helper "dhcp-helper -n -s 1…" dhcp-helper running
pihole "start.sh" pihole running (healthy) 0.0.0.0:53->53/tcp, 0.0.0.0:53->53/udp, :::53->53/tcp, :::53->53/udp
traefik "/entrypoint.sh trae…" traefik running 0.0.0.0:80->80/tcp, 0.0.0.0:443->443/tcp, 0.0.0.0:8080->8080/tcp, :::80->80/tcp, :::443->443/tcp, :::8080->8080/tcp
Image is latest:
pihole pihole/pihole latest cf5e7ddfcd9a 106MB
latest is just the tag as present at the time the image was downloaded, so you could still have been running from a v5 image.
But size as well as the COMMAND from the container list suggest it's indeed a v6 image and container.
Contrary to your description, your docker compose is void of any FTLCONF_webserver_port or ports declarations for port 80.
What's your container's network mode?
When that mode is allowing your container to declare ports, as your compose suggests, there would be not need to adjust FTLCONF_webserver_port.
Did you try having Docker map port 80 yet?
ports:
- 53:53/tcp
- 53:53/udp
- 8081:80/tcp
Thanks again for the reply – can't @ you as I'm new here 
Sorry, the config I posted was the last config I'd tried, i.e. not specifying a port, running with the defaults of 80,443. Specifying the defaults under port would error as traefik already occupies those ports on the host, so my hope was that I'd be able to get away with only exposing the ports on the docker network vs mapping to host ports.
I've just tried FTLCONF_webserver_port: 8089 now and… appear to have gotten it working. It didn't seem to work on port 8081, however this works. I have no idea why if I'm honest, but I'll take it 
Thanks for your help, it's appreciated.
Updated compose snippet in case it helps anyone else:
pihole:
image: pihole/pihole:latest
container_name: pihole
hostname: pihole
networks:
network_name:
ipv4_address: 10.5.0.3
dns:
- 127.0.0.1
- 1.1.1.1
ports:
- 53:53/tcp
- 53:53/udp
expose:
- 8089
environment:
TZ: Europe/London
FTLCONF_dns_listeningMode: all
FTLCONF_dns_upstreams: 10.5.0.4#5053
FTLCONF_webserver_domain: "pihole.domain.com"
FTLCONF_webserver_interface_theme: default-auto
FTLCONF_webserver_interface_boxed: false
FTLCONF_webserver_port: 8089
volumes:
- "./pihole/etc-pihole:/etc/pihole"
- "./pihole/etc-dnsmasq.d:/etc/dnsmasq.d"
cap_add:
- NET_ADMIN
depends_on:
- cloudflared
labels:
- "traefik.enable=true"
- "traefik.http.routers.pihole.tls=true"
- "traefik.http.routers.pihole.rule=Host(`pihole.domain.com`)"
- "traefik.http.middlewares.pihole-redirect.redirectregex.regex=^https://pihole.domain.com/?$$"
- "traefik.http.middlewares.pihole-redirect.redirectregex.replacement=https://pihole.domain.com/admin"
- "traefik.http.services.pihole.loadbalancer.server.port=8089"
- "traefik.http.services.pihole.loadbalancer.passhostheader=true"
restart: unless-stopped
I see no reason why mapping - 8089:80/tcp should not have worked, without the need to also set FTLCONF_webserver_port.
The correct variable is FTLCONF_webserver_api_port.
I made a confusion... The variable you used is correct.