82 lines
3.8 KiB
Markdown
82 lines
3.8 KiB
Markdown
# go-dns — Project Specification
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## Overview
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**go-dns** is a Go library for authoritative DNS operations against **BIND** (and compatible servers):
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- **Dynamic updates** — RFC 2136 add and delete of records ([RFC 2136](https://www.rfc-editor.org/rfc/rfc2136)); prerequisite sections are out of scope
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- **Zone transfer** — full **AXFR** only ([RFC 5936](https://www.rfc-editor.org/rfc/rfc5936)); IXFR is out of scope for v1
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- **TSIG authentication** — callers supply existing shared keys; key generation is out of scope
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Callers perform updates and full zone reads in Go with an in-memory zone (`Record` rdata is presentation format) and **typed RR builders** instead of shelling out to `nsupdate` or `dig axfr`.
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## Module metadata
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| Item | Value |
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|------|-------|
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| Module path | `gitea.neitzel.de/konrad/go-dns` |
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| Go version | `go 1.27.0` in this module's `go.mod` |
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| Public package | **`godns`** (`package godns` at module root) |
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| Git remote | `ssh://git@gitea.neitzel.de:2222/konrad/go-dns.git` |
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This is a **Library** in the ExApp Workspace. Workspace Go rules live in `.cursor/rules/` (`go.mdc`, `go-testing.mdc`). Specs, Issues, and ADRs for this Library live in the Workspace (`docs/issues/`, `docs/adr/go-dns/`), not in this repository.
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## Target environment
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| Item | Value |
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|------|-------|
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| Nameserver | BIND 9.x (primary reference) |
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| Protocols | RFC 2136 UPDATE (UDP + **automatic TCP fallback**); **AXFR over TCP** |
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| Authentication | TSIG (RFC 2845 / RFC 8945) — required for documented happy path |
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| Domain names | **ASCII only** in v1 (no IDNA) |
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| Out of scope (v1) | IXFR, full DNS server, recursive resolver, TSIG key generation, IDNA |
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## Supported operation surface
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1. **Session & TSIG key** — server, zone, transport, existing key (name, algorithm, secret)
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2. **Dynamic update** — add, delete, and batch UPDATE; typed RR builders (`A`, `AAAA`, `MX`, `TXT`, `CNAME`, `NS`, `SRV`, `PTR`, `CAA`)
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3. **Zone transfer** — **AXFR** only; parse stream into zone data
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4. **Zone data model** — `Record`, `RRSet`, `Zone`, `UpdateResult`, `TransferResult`
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5. **BIND guide** — [bind-tsig-configuration.md](bind-tsig-configuration.md) (`allow-update` + `allow-transfer` for a TSIG key)
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## API style
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- **Typed builders** per RR type (`A`, `AAAA`, `MX`, `TXT`, `CNAME`, `NS`, `SRV`, `PTR`, `CAA`) — not a generic `(type, rdata string)` API
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- How to call them: [guide.md](guide.md). Every exported symbol: [api.md](api.md)
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## Zone data model (logical)
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| Type | Purpose |
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|------|---------|
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| **Record** | Single RR: owner, class, type, TTL, presentation-format rdata |
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| **RRSet** | Group of RRs with same owner/class/type |
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| **Zone** | Origin + full record set + SOA/serial (complete zone in memory) |
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| **UpdateResult** | UPDATE response status |
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| **TransferResult** | AXFR result + populated `Zone` + serial metadata |
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## BIND configuration
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Operators configure BIND so a TSIG key may **update** and **transfer** a zone (`allow-update`, `allow-transfer`). Step-by-step instructions, security notes, and a minimal `named.conf` example:
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**[bind-tsig-configuration.md](bind-tsig-configuration.md)**
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## Tests
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| Command | Purpose |
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|---------|---------|
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| `go test ./...` | Unit tests (encoding, parsing, zone model, typed builders). Fails when `docs/api.md` is stale |
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| `UPDATE_API_DOCS=1 go test -run TestAPIDoc -count=1` | Rewrite `docs/api.md` after an exported API change |
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| `go test -tags=integration ./...` | **BIND testcontainer** (Docker required) |
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Follow the Workspace `.cursor/rules/go-testing.mdc`. This Library's integration image is BIND.
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## Package layout
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```
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package godns # public API at module root
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docs/guide.md # consumer guide
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docs/api.md # generated exported API
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docs/project-specification.md
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docs/bind-tsig-configuration.md
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```
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