plan(kez-chat): NATS is bundled in docker-compose, not in Rust code

Correcting an overcorrection. Previous version pushed NATS fully
external — "operator brings their own, we don't ship it." That went
too far. The right line is:

- NATS isn't *Rust code we wrote* — it's the official Go nats-server,
  separate process. We don't embed it. ✓ (unchanged)
- NATS *is* part of our deployment recipe — docker-compose includes a
  `nats` service alongside chat-server and sig-server so operators
  can `docker compose up` and have everything working.

This is the standard "we ship docker-compose with the dependencies
wired up" pattern (like projects that include Postgres in their
compose). Operators with existing NATS deployments can disable the
bundled service and set NATS_URL to their own broker.

Changes:

- §4.2 process diagram: NATS back inside the "our deployment" box,
  with a note that it's bundled-but-separable
- §4.3 docker-compose: nats service restored alongside chat-server
  and sig-server. Reference nats.conf path documented. Instructions
  for swapping in your own NATS broker.
- §6.4 NATS section retitled from "external dependency" to
  "bundled in compose, not in code." Same requirements (NATS 2.10+,
  JetStream, auth_callout) but framed as turn-key by default.
- Decisions-locked NATS row updated: "not in Rust code, yes in
  docker-compose; swap-able by config."
- §11 sequenced plan step 3: wire up the bundled nats service rather
  than "spin up a separate broker for dev."
- §12 summary: "we ship two Rust services PLUS a docker-compose
  recipe that includes nats-server."
- Appendix A trimmed: now just "running NATS standalone if you're
  iterating on chat-server in cargo watch and don't want the full
  compose stack." The full compose IS the standard dev setup.
This commit is contained in:
Tudisco 2026-05-24 22:45:29 -06:00
parent f0aa86f71a
commit 7b8b136e92

View File

@ -194,65 +194,71 @@ becomes a fourth optional container.
### 4.2 Process / deployment model
NATS is **not part of our deployment.** The operator runs NATS however
they want (Synadia Cloud, their own cluster, a friend's broker, a single
local container) and gives the chat-server a URL. Same idea as a
database: we connect to one; we don't ship one.
NATS is **not embedded in our Rust code** — it's a separate process
(the official Go `nats-server`). But we **do bundle it in our deployment
recipe** so operators get a turn-key setup. Same pattern as projects
that ship docker-compose with Postgres included: we don't write the
database, but we wire it up so you can `docker compose up` and have
everything working.
```
External infrastructure
(operator's responsibility)
┌──────────────────────┐
│ NATS broker │
│ + JetStream │
│ somewhere │
└─────────▲─────▲──────┘
│ │
chat-server ──────┘ │ ◄────── client app
(auth callout) │ (publish/subscribe)
┌─────────────── our deployment ─────────────────┐
│ │
│ ┌─────────────────┐ ┌────────────────┐ │
│ │ kez-chat-server │ │ kez-sig-server │ │
│ │ (Rust) │ │ (Rust) │ │
│ │ │ │ │ │
│ │ ↓ handles │ │ ↓ sigchain │ │
│ │ ↓ nats auth │ │ storage │ │
│ │ ↓ HTTP API │ │ │ │
│ └─────────────────┘ └────────────────┘ │
│ ▲ ▲ │
└─────────┼──────────────────────┼───────────────┘
│ │
┌──────┴──────────────────────┴────────────────────────┐
│ Chat app (per user, runs on phone/desktop) │
│ │
│ • talks to the operator's NATS broker (NATS proto) │
│ • talks to kez-chat-server over HTTPS │
│ • talks to kez-sig-server over HTTPS │
│ • runs local iroh::Node for file send/receive │
└──────────────────────────────────────────────────────┘
┌────────────────── our deployment (docker-compose) ────────────────┐
│ │
│ ┌──────────────┐ ┌─────────────────┐ ┌────────────────┐ │
│ │ nats-server │ │ kez-chat-server │ │ kez-sig-server │ │
│ │ (Go) │◄──┤ (Rust) ├──►│ (Rust) │ │
│ │ + JetStream │ │ │ │ (existing) │ │
│ │ │ │ ↓ handles │ │ ↓ sigchain │ │
│ │ ↓ chat msgs │ │ ↓ nats auth │ │ storage │ │
│ │ ↓ tickets │ │ ↓ HTTP API │ │ │ │
│ └──────────────┘ └─────────────────┘ └────────────────┘ │
│ ▲ ▲ ▲ │
└─────────┼───────────────────┼──────────────────────┼──────────────┘
│ │ │
┌──────┴───────────────────┴──────────────────────┴───────────┐
│ Chat app (per user, runs on phone/desktop) │
│ │
│ • talks to nats-server over native NATS protocol │
│ • talks to kez-chat-server over HTTPS │
│ • talks to kez-sig-server over HTTPS │
│ • runs local iroh::Node for file send/receive │
└──────────────────────────────────────────────────────────────┘
```
The chat-server orchestrates auth against whatever NATS broker is
configured, but doesn't run, host, supervise, or ship NATS in any form.
The chat-server orchestrates auth between NATS and the handle registry.
NATS runs in its own container; we ship the config wired up.
### 4.3 docker-compose sketch (our two services only)
**Operators who already run NATS** can disable our bundled `nats`
service and point `NATS_URL` at their own broker — same auth_callout
config snippet works in any NATS deployment. Bundled NATS is the
default for convenience, not a requirement.
### 4.3 docker-compose recipe
```yaml
# deploy/docker-compose.yml — what we ship
# deploy/docker-compose.yml
services:
nats:
image: nats:latest
command: ["-c", "/etc/nats/nats.conf", "--jetstream"]
volumes:
- ./nats.conf:/etc/nats/nats.conf:ro
- nats-data:/data
ports:
- "4222:4222" # client connections (TLS in prod)
- "8222:8222" # monitoring
chat-server:
build: . # kez-chat-server Rust binary
environment:
NATS_URL: ${NATS_URL} # operator points us at their NATS broker
NATS_URL: nats://nats:4222
SIG_SERVER_URL: http://sig-server:7878
DB_PATH: /data/handles.db
AUTH_CALLOUT_NKEY_PATH: /etc/kez/auth-callout.nkey
volumes:
- chat-data:/data
- ./auth-callout.nkey:/etc/kez/auth-callout.nkey:ro
depends_on: [sig-server]
depends_on: [nats, sig-server]
ports:
- "8080:8080" # HTTP API for clients
@ -266,19 +272,23 @@ services:
- "7878:7878"
volumes:
nats-data:
chat-data:
sig-data:
```
**NATS is not in this file.** The operator brings their own — running
on a different host, in a different compose project, on Synadia Cloud,
or wherever. They give us `NATS_URL` and a place to put our auth
callout endpoint URL in their `nats.conf`.
We ship a reference `deploy/nats.conf` with the auth_callout wired up
to talk to our chat-server. Operators who want to bring their own
NATS:
What the operator needs to add on the NATS side (in **their** config):
1. Comment out (or delete) the `nats` service from the compose file.
2. Set `NATS_URL=nats://your-broker:4222` in the chat-server's env.
3. Apply our reference `nats.conf` snippet to their NATS deployment.
The auth_callout config snippet:
```conf
# nats.conf — added to whatever NATS deployment the operator runs
# nats.conf — patched into whichever NATS deployment is used
authorization {
auth_callout {
issuer: "<our auth-callout signing nkey public part>"
@ -293,11 +303,6 @@ that NATS trusts. When a client connects to NATS with their KEZ
ed25519 key, NATS forwards the auth request to our chat-server,
which checks the handle registry and signs a yes/no response.
We provide a reference `nats.conf` snippet in the docs. The operator
patches it into their own NATS deployment.
For local development, see Appendix A.
### 4.4 Endpoints
```
@ -519,43 +524,46 @@ import cleanly from the start.
- `iroh` — server doesn't run an Iroh node in v0 (no pinning)
- nats-server (Go) — separate container, not a Rust dep
### 6.4 NATS broker — external dependency
### 6.4 NATS broker — bundled in compose, not in code
NATS is **not part of our project**. It's external infrastructure the
operator provides, the same way they'd provide a database or an SMTP
relay. We ship:
NATS is **not embedded in the Rust binary** — it's the official Go
`nats-server` running as its own container. But we **do include it
in the docker-compose deployment** so `docker compose up` is the
whole setup for new operators. Same pattern as projects shipping
Postgres-in-compose: it's bundled for convenience, not because we
wrote a database.
- An `async-nats` client used by the chat-server (admin/utility work)
- An auth-callout HTTP endpoint that NATS calls during client connection
- A documented `nats.conf` snippet operators add to their NATS deployment
- A reference local-dev setup (Appendix A) for running NATS yourself
while developing
What we ship:
What we require from the operator's NATS:
- `deploy/docker-compose.yml` with a `nats` service alongside our
Rust services
- `deploy/nats.conf` — reference config with auth_callout wired up
- `async-nats` client inside chat-server for admin/utility work
- The auth-callout HTTP endpoint chat-server exposes for NATS to call
What NATS we require (whether bundled or BYO):
| Requirement | Why |
|---|---|
| **NATS 2.10+** (for auth_callout) | We rely on auth callout to bridge KEZ identity into NATS |
| **NATS 2.10+** (for auth_callout) | We use auth_callout to bridge KEZ identity into NATS |
| **JetStream enabled** | For offline message buffering (durable consumers) |
| **TCP reachable** from chat-server and clients | Standard |
| **TLS** (in production) | Standard |
| **auth_callout configured** to hit our endpoint | Required for client auth |
| **auth_callout configured** to hit our chat-server endpoint | Required for client auth |
That's it. Operator can run a single Docker container, a clustered
production deployment, or a managed service — we don't care, as long
as `NATS_URL` and the callout config are correct.
**Swapping in your own NATS** is a config change, not a code change:
disable the bundled `nats` service in the compose, set `NATS_URL` to
your own broker, apply our `nats.conf` snippet there. Useful for
operators with existing NATS infrastructure, Synadia Cloud users, etc.
Why fully external rather than alongside us:
Why bundled rather than embedded:
- NATS is a serious piece of infrastructure with its own scaling and
operational concerns. Bundling it implies we're responsible for it.
We're not.
- Operators with existing NATS deployments can reuse them. No "now run
our copy of NATS too."
- Different teams might run different NATS topologies (single instance,
cluster, mesh, leaf nodes). None of that is our problem.
- Swapping NATS implementations or moving to a managed provider is a
config change, not a code change.
- NATS is a 200KLOC Go service with its own ops story. We're not
rewriting it in Rust just to embed it.
- Bundling it as a separate process keeps the architecture honest —
if NATS misbehaves, it's a separate process to restart, debug, log.
- Operators can swap to a different broker deployment without touching
our code.
### 6.5 Iroh — client-side only
@ -646,7 +654,7 @@ Settle yes/no on this and the design is locked.
| Question | Decision |
|---|---|
| Bundle sigchain in chat-server? | **No.** Use existing `kez-sig-server`. Microservices. |
| Bundle NATS into Rust server? | **No.** NATS is external infrastructure the operator provides. We don't ship, embed, or supervise it. We connect to whatever broker `NATS_URL` points at. |
| Bundle NATS into Rust server? | **Not in the Rust code** — NATS stays the official Go `nats-server` running as its own process. **Yes in our docker-compose** — operators get `nats + chat-server + sig-server` wired up out of the box. Operators with existing NATS deployments can disable the bundled service and set `NATS_URL` to point elsewhere. |
| KEZ + nostr coexistence for chat? | **No nostr in chat.** KEZ is identity-only; nostr only as a verifiable claim in someone's sigchain, not as transport. |
| Handle scope: federation or global? | **Global for v0**, federation-ready design (see §3.5). |
| Recovery if key lost? | **Paper backup (24-word mnemonic), Keybase-style.** No server-side recovery. |
@ -701,8 +709,9 @@ When we start building:
Handle registry + WebFinger first — these unblock client-side
account creation.
3. **NATS auth callout.** Bring up a NATS broker for development (see
Appendix A), configure its auth_callout to hit our chat-server's
3. **NATS auth callout.** Wire up the `nats` service in our compose
(or, in dev, run `nats-server -c deploy/nats.conf --jetstream`
locally). Its auth_callout hits our chat-server's
`/internal/nats/auth`. End-to-end: a client can register a handle
and then connect to NATS authenticated by its KEZ key.
@ -737,11 +746,15 @@ ed25519 primary key. The same key authenticates to a NATS broker
(chat, presence, file tickets — broker is dumb, clients do E2E with
ChaCha20-Poly1305 over X25519-derived keys) and identifies an Iroh
node (P2P bulk transfer, content-addressed blobs, on-demand fetch).
**Our project ships two services**: a thin Rust `kez-chat-server`
that handles the handle registry + NATS auth callout + HTTP API, and
the existing `kez-sig-server` that stores sigchains. **NATS is
external infrastructure the operator provides** — we never ship,
embed, or supervise it. The chat-server does not run an Iroh node
**Our project ships two Rust services** (`kez-chat-server` for handle
registry + NATS auth callout + HTTP API, and the existing
`kez-sig-server` for sigchain storage) **plus a docker-compose recipe
that includes `nats-server`** for turn-key deployment. NATS isn't in
our Rust code — it's the official Go binary running as its own
container — but it's wired up in our compose so operators can
`docker compose up` and have everything working. Operators with
existing NATS deployments can disable the bundled service and point
us elsewhere. The chat-server does not run an Iroh node
and does not pin files in v0; file transfer is pure P2P between
online peers. Account recovery is via a 24-word paper-backup
mnemonic. Federation across home servers is deferred but the design
@ -749,26 +762,21 @@ keeps it as a flip-the-switch future change.
---
## Appendix A: running a NATS broker locally for development
## Appendix A: running just NATS during development
NATS is not part of our project, but you need one running to test the
chat-server end-to-end. Easiest path during development:
The full deployment is `docker compose up` in `deploy/` — that brings
nats, chat-server, and sig-server together. But if you're iterating on
chat-server in `cargo watch` and want a standalone NATS to point at:
```sh
docker run -d --name kez-dev-nats \
-p 4222:4222 -p 8222:8222 \
-v "$PWD/dev-nats.conf:/etc/nats/nats.conf:ro" \
-v "$PWD/deploy/nats.conf:/etc/nats/nats.conf:ro" \
nats:latest -c /etc/nats/nats.conf --jetstream
```
Where `dev-nats.conf` enables the auth callout pointing at your
locally-running chat-server (e.g. `http://host.docker.internal:8080/internal/nats/auth`).
Point your locally-running chat-server at it with
`NATS_URL=nats://127.0.0.1:4222`. The auth_callout in the same
`nats.conf` will reach back to `http://host.docker.internal:8080/internal/nats/auth`.
A full reference `dev-nats.conf` will live at `deploy/dev-nats.conf`
when we start building. This appendix exists so developers have a
one-liner to spin up NATS for testing; **it is not the production
deployment recipe** (operators run their own NATS however they want).
For production: see the NATS docs (https://docs.nats.io). Our project
has no opinion beyond "must be 2.10+ with JetStream + auth_callout
configured to hit our endpoint."
Tear down with `docker rm -f kez-dev-nats` when done.