docs: move dns-automation plan to completed

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/plans/completed/dns-automation.md

@@ -0,0 +1,61 @@
+# DNS Automation
+
+**Status:** Completed (2026-02-04)
+
+**Goal:** Automatically generate DNS entries from host configurations
+
+**Approach:** Leverage Nix to generate zone file entries from flake host configurations
+
+Since most hosts use static IPs defined in their NixOS configurations, we can extract this information and automatically generate A records. This keeps DNS in sync with the actual host configs.
+
+## Implementation
+
+- [x] Add optional CNAME field to host configurations
+  - [x] Added `homelab.dns.cnames` option in `modules/homelab/dns.nix`
+  - [x] Added `homelab.dns.enable` to allow opting out (defaults to true)
+  - [x] Documented in CLAUDE.md
+- [x] Create Nix function to extract DNS records from all hosts
+  - [x] Created `lib/dns-zone.nix` with extraction functions
+  - [x] Parses each host's `networking.hostName` and `systemd.network.networks` IP configuration
+  - [x] Collects CNAMEs from `homelab.dns.cnames`
+  - [x] Filters out VPN interfaces (wg*, tun*, tap*, vti*)
+  - [x] Generates complete zone file with A and CNAME records
+- [x] Integrate auto-generated records into zone files
+  - [x] External hosts separated to `services/ns/external-hosts.nix`
+  - [x] Zone includes comments showing which records are auto-generated vs external
+- [x] Update zone file serial number automatically
+  - [x] Uses `self.sourceInfo.lastModified` (git commit timestamp)
+- [x] Test zone file validity after generation
+  - [x] NSD validates zone at build time via `nsd-checkzone`
+- [x] Deploy process documented
+  - [x] Merge to master, run auto-upgrade on ns1/ns2
+
+## Files Created/Modified
+
+| File | Purpose |
+|------|---------|
+| `modules/homelab/dns.nix` | Defines `homelab.dns.*` options |
+| `modules/homelab/default.nix` | Module import hub |
+| `lib/dns-zone.nix` | Zone generation functions |
+| `services/ns/external-hosts.nix` | Non-flake host records |
+| `services/ns/master-authorative.nix` | Uses generated zone |
+| `services/ns/secondary-authorative.nix` | Uses generated zone |
+
+## Usage
+
+View generated zone:
+```bash
+nix eval .#nixosConfigurations.ns1.config.services.nsd.zones.'"home.2rjus.net"'.data --raw
+```
+
+Add CNAMEs to a host:
+```nix
+homelab.dns.cnames = [ "alias1" "alias2" ];
+```
+
+Exclude a host from DNS:
+```nix
+homelab.dns.enable = false;
+```
+
+Add non-flake hosts: Edit `services/ns/external-hosts.nix`

docs/plans/nixos-improvements.md

@@ -2,30 +2,6 @@
 
 This document contains planned improvements to the NixOS infrastructure that are not directly part of the automated deployment pipeline.
 
-## DNS Automation
+## Completed
 
-**Goal:** Automatically generate DNS entries from host configurations
+- [DNS Automation](completed/dns-automation.md) - Automatically generate DNS entries from host configurations
-
-**Approach:** Leverage Nix to generate zone file entries from flake host configurations
-
-Since most hosts use static IPs defined in their NixOS configurations, we can extract this information and automatically generate A records. This keeps DNS in sync with the actual host configs.
-
-**Tasks:**
-- [ ] Add optional CNAME field to host configurations
-  - [ ] Add `networking.cnames = [ "alias1" "alias2" ]` or similar option
-  - [ ] Document in host configuration template
-- [ ] Create Nix function to extract DNS records from all hosts
-  - [ ] Parse each host's `networking.hostName` and IP configuration
-  - [ ] Collect any defined CNAMEs
-  - [ ] Generate zone file fragment with A and CNAME records
-- [ ] Integrate auto-generated records into zone files
-  - [ ] Keep manual entries separate (for non-flake hosts/services)
-  - [ ] Include generated fragment in main zone file
-  - [ ] Add comments showing which records are auto-generated
-- [ ] Update zone file serial number automatically
-- [ ] Test zone file validity after generation
-- [ ] Either:
-  - [ ] Automatically trigger DNS server reload (Ansible)
-  - [ ] Or document manual step: merge to master, run upgrade on ns1/ns2
-
-**Deliverable:** DNS A records and CNAMEs automatically generated from host configs