Add Pi-hole and Traefik LXC containers

- LXC 103 (pihole): Debian 12, 10.10.1.2, Pi-hole v6 with local DNS for
  gitea/grafana/traefik/pihole.homelab, Proxmox dnsmasq updated to use
  Pi-hole upstream
- LXC 104 (traefik): Debian 12, 10.10.1.3, Traefik v3 routing
  gitea.homelab → 10.10.1.125:3000, grafana.homelab → 10.10.1.137:3000
- DNAT rules on vmbr0 forwarding :80/:443 to Traefik, persisted in
  /etc/network/interfaces
- Ansible roles: pihole, traefik; playbooks: pihole.yml, traefik.yml
- site.yml excludes Debian containers from Arch-specific common role

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ansible/roles/pihole/defaults/main.yml

@@ -0,0 +1,11 @@
+---
+pihole_password: "{{ vault_pihole_password }}"
+pihole_dns_upstream1: "8.8.8.8"
+pihole_dns_upstream2: "8.8.4.4"
+pihole_local_domain: "homelab"
+pihole_interface: "eth0"
+pihole_dns_hosts:
+  - { ip: "10.10.1.2",   host: "pihole.homelab" }
+  - { ip: "10.10.1.3",   host: "traefik.homelab" }
+  - { ip: "10.10.1.125", host: "gitea.homelab" }
+  - { ip: "10.10.1.137", host: "grafana.homelab" }

ansible/roles/pihole/handlers/main.yml

@@ -0,0 +1,10 @@
+---
+- name: Restart pihole-FTL
+  ansible.builtin.service:
+    name: pihole-FTL
+    state: restarted
+
+- name: Update pihole hosts
+  ansible.builtin.command:
+    cmd: python3 /tmp/pihole_update_hosts.py
+  notify: Restart pihole-FTL

ansible/roles/pihole/tasks/main.yml

@@ -0,0 +1,58 @@
+---
+- name: Install Pi-hole dependencies
+  ansible.builtin.apt:
+    name:
+      - curl
+      - git
+      - libcap2-bin
+      - dns-root-data
+    state: present
+    update_cache: true
+
+- name: Create Pi-hole config directory
+  ansible.builtin.file:
+    path: /etc/pihole
+    state: directory
+    mode: "0755"
+
+- name: Write Pi-hole setup vars
+  ansible.builtin.template:
+    src: setupVars.conf.j2
+    dest: /etc/pihole/setupVars.conf
+    mode: "0644"
+
+- name: Check if Pi-hole is already installed
+  ansible.builtin.stat:
+    path: /usr/local/bin/pihole
+  register: pihole_binary
+
+- name: Download Pi-hole installer
+  ansible.builtin.get_url:
+    url: https://install.pi-hole.net
+    dest: /tmp/pihole-install.sh
+    mode: "0755"
+  when: not pihole_binary.stat.exists
+
+- name: Run Pi-hole unattended installer
+  ansible.builtin.command:
+    cmd: /tmp/pihole-install.sh --unattended
+    creates: /usr/local/bin/pihole
+  when: not pihole_binary.stat.exists
+
+- name: Set Pi-hole web password
+  ansible.builtin.command:
+    cmd: /usr/local/bin/pihole setpassword "{{ pihole_password }}"
+  changed_when: true
+
+- name: Set local DNS hosts in pihole.toml
+  ansible.builtin.template:
+    src: update_hosts.py.j2
+    dest: /tmp/pihole_update_hosts.py
+    mode: "0755"
+  notify: Update pihole hosts
+
+- name: Ensure pihole-FTL is running
+  ansible.builtin.service:
+    name: pihole-FTL
+    state: started
+    enabled: true

ansible/roles/pihole/templates/setupVars.conf.j2

@@ -0,0 +1,15 @@
+PIHOLE_INTERFACE={{ pihole_interface }}
+PIHOLE_DNS_1={{ pihole_dns_upstream1 }}
+PIHOLE_DNS_2={{ pihole_dns_upstream2 }}
+QUERY_LOGGING=true
+INSTALL_WEB_SERVER=true
+INSTALL_WEB_INTERFACE=true
+LIGHTTPD_ENABLED=true
+CACHE_SIZE=10000
+DNS_FQDN_REQUIRED=false
+DNS_BOGUS_PRIV=true
+DNSMASQ_LISTENING=local
+WEBPASSWORD=
+BLOCKING_ENABLED=true
+PIHOLE_DOMAIN={{ pihole_local_domain }}
+IPV4_ADDRESS=10.10.1.2/24

ansible/roles/pihole/templates/update_hosts.py.j2

@@ -0,0 +1,22 @@
+#!/usr/bin/env python3
+import re
+
+hosts = [
+{% for h in pihole_dns_hosts %}
+    "{{ h.ip }} {{ h.host }}",
+{% endfor %}
+]
+
+hosts_str = "[" + ", ".join('"' + h + '"' for h in hosts) + "]"
+
+with open("/etc/pihole/pihole.toml", "r") as f:
+    content = f.read()
+
+content = re.sub(
+    r"(?m)^( *hosts\s*=\s*)\[.*\]",
+    r"\g<1>" + hosts_str,
+    content,
+)
+
+with open("/etc/pihole/pihole.toml", "w") as f:
+    f.write(content)