infra/docs
Viktor Barzin e6e5fc5f17 [docs] Mailserver architecture — richer diagrams + steady-state accuracy [ci skip]
## Context

After code-yiu Phases 1a–6 landed, `docs/architecture/mailserver.md` still
carried the pre-HAProxy Mermaid diagram, a retired Dovecot-exporter
component row, stale PVC names (`-proxmox` suffixes that were renamed
`-encrypted` during the LUKS migration), a wrong probe schedule
(claimed 10 min, actually 20 min), and a Mailgun-API claim for the
probe (it's been on Brevo since code-n5l). The two-path architecture
(external-via-HAProxy + intra-cluster-via-ClusterIP) that defines the
current design wasn't visualised at all.

## This change

Rewrote the Architecture Diagram section to show **both ingress paths
in one Mermaid flowchart**, colour-coded:

- External (orange): Sender → pfSense NAT → HAProxy → NodePort →
  **alt PROXY listeners** (2525/4465/5587/10993).
- Intra-cluster (blue): Roundcube / probe → ClusterIP Service →
  **stock listeners** (25/465/587/993), no PROXY.
- The pod subgraph shows both listener sets feeding the same Postfix /
  Rspamd / Dovecot / Maildir pipeline.
- Security dotted edges: Postfix log stream → CrowdSec agent →
  LAPI → pfSense bouncer decisions.
- Monitoring dotted edges: probe → Brevo HTTP → MX → pod → IMAP →
  Pushgateway/Uptime Kuma.

Added a **sequenceDiagram** for the external SMTP roundtrip — walks
through the wire-level handshake from external MTA → pfSense NAT →
HAProxy TCP connect → PROXY v2 header write → kube-proxy SNAT → pod
postscreen parse → smtpd banner. Makes the "how does the pod see the
real IP despite SNAT?" question self-answering.

Added a **Port mapping table** listing all 8 container listeners (4
stock + 4 alt) with their Service, NodePort, PROXY-required flag, and
who uses each path. Replaces the ambiguous prose about "alt ports".

Fixed stale bits:
- Removed Dovecot Exporter row from Components (retired in code-1ik).
- Added pfSense HAProxy row.
- Probe schedule: every 10 min → **every 20 min** (`*/20 * * * *`).
- Probe API: Mailgun → **Brevo HTTP**.
- PVC names: `-proxmox` → **`-encrypted`** (all three); storage class
  `proxmox-lvm` → **`proxmox-lvm-encrypted`**.
- Added `mailserver-backup-host` + `roundcube-backup-host` RWX NFS
  PVCs to the Storage table with backup flow pointer.
- Expanded Troubleshooting → Inbound to include HAProxy health check
  + container-listener verification steps.
- Secrets table: `brevo_api_key` now marked as used by both relay +
  probe; `mailgun_api_key` marked historical.

Added a prominent **UPDATE 2026-04-19** header to
`docs/runbooks/mailserver-proxy-protocol.md` pointing future readers
at the implemented state in `mailserver-pfsense-haproxy.md`. Research
doc preserved as a decision record — it's the canonical "why not just
pin the pod?" reference.

## What is NOT in this change

- No Terraform changes; this is docs-only.
- No changes to the runbook (`mailserver-pfsense-haproxy.md`) — it was
  already rewritten during Phase 6.

## Test Plan

### Automated
```
$ awk '/^```mermaid/ {c++} END{print c}' docs/architecture/mailserver.md
2
$ grep -c '\-encrypted' docs/architecture/mailserver.md
5  # PVC references normalised
$ grep -c '\-proxmox' docs/architecture/mailserver.md
0  # no stale names left
```

### Manual Verification
Render `docs/architecture/mailserver.md` on GitHub or any Mermaid-
capable viewer:
1. Top Architecture Diagram should show two labelled paths into the
   pod, colour-coded (orange = external, blue = intra-cluster).
2. Sequence diagram should show 10 numbered steps ending at Rspamd +
   Dovecot delivery.
3. Port Mapping table should make it obvious that the 4 alt container
   ports are only reachable via `mailserver-proxy` NodePort and require
   PROXY v2.
2026-04-19 12:40:53 +00:00
..
architecture [docs] Mailserver architecture — richer diagrams + steady-state accuracy [ci skip] 2026-04-19 12:40:53 +00:00
plans [docs] Update anti-AI and rybbit docs after rewrite-body removal 2026-04-17 21:43:13 +00:00
post-mortems [docs] post-mortem: clarify the sizeLimit vs container memory limit gotcha 2026-04-18 13:23:14 +00:00
runbooks [docs] Mailserver architecture — richer diagrams + steady-state accuracy [ci skip] 2026-04-19 12:40:53 +00:00
README.md add architecture documentation for all infrastructure subsystems [ci skip] 2026-03-24 00:55:25 +02:00

Infrastructure Documentation

This repository contains the configuration and documentation for a homelab Kubernetes cluster running on Proxmox. The infrastructure hosts 70+ services managed declaratively with Terraform and Terragrunt.

Quick Reference

Network Ranges

  • Physical Network: 192.168.1.0/24 - Physical devices and host network
  • Management VLAN 10: 10.0.10.0/24 - Infrastructure VMs and management
  • Kubernetes VLAN 20: 10.0.20.0/24 - Kubernetes cluster network

Key URLs

  • Public: viktorbarzin.me
  • Internal: viktorbarzin.lan

Architecture Documentation

Document Description
Overview Infrastructure overview, hardware specs, VM inventory, and service catalog
Networking Network topology, VLANs, routing, and firewall rules
VPN Headscale mesh VPN and Cloudflare Tunnel configuration
Storage TrueNAS NFS, democratic-csi, and persistent volume management
Authentication Authentik SSO, OIDC flows, and service integration
Security CrowdSec IPS, Kyverno policies, and security controls
Monitoring Prometheus, Grafana, Loki, and observability stack
Secrets Management HashiCorp Vault integration and secret rotation
CI/CD Woodpecker CI pipeline and deployment automation
Backup & DR Backup strategy, disaster recovery, and restore procedures
Compute Proxmox VMs, GPU passthrough, K8s resource management, and VPA
Databases PostgreSQL, MySQL, Redis, and database operators
Multi-tenancy Namespace isolation, tier system, and resource quotas

Operations

  • Runbooks - Step-by-step operational procedures
  • Plans - Infrastructure change plans and rollout strategies

Getting Started

  1. Review the Overview for a high-level understanding
  2. Read the Networking doc to understand connectivity
  3. Check Compute for resource management patterns
  4. Explore individual architecture docs based on your area of interest