glm-5.1
fe1ae6c05e
Resolve OQ-08 through OQ-12 after reviewing implementation findings: - OQ-08: Remove /health route from the main HTTPS listener entirely. Health checking belongs on port 9900 and admin socket only, not on the public-facing proxy. This eliminates upstream collision problems and special-case routing logic. (ADR-022) - OQ-09: Not an architectural unknown — ADR-015 already decided on a separate connect timeout. The implementation gap is a known issue. - OQ-10: Not an open question — acme_contact is already specified as required in config.md. The empty contact list is bug C2. - OQ-11: Hardcoded is_https=true is correct for a TLS-terminating proxy. HTTP listener redirects, doesn't proxy. Just needs a comment. - OQ-12: Access logging is already specified as mandatory/always-on in operations.md. Missing log_request! calls are bug W13. Updated docs: proxy.md, operations.md, overview.md, config.md, open-questions.md, README.md, ADR-013. Created ADR-022.
84 lines
5.4 KiB
Markdown
84 lines
5.4 KiB
Markdown
---
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status: draft
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last_updated: 2026-06-12
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---
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# Reverse Proxy — Architecture
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## Current State
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**Phase 0 (Exploration) — Complete.** Phase 1 (Architecture) — In progress.
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This project replaces our vulnerable nginx 1.24.0 installation with a
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memory-safe Rust/axum reverse proxy. The primary motivation is CVE-2026-42945
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(unauthenticated RCE in nginx's rewrite module) and the broader pattern of
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memory corruption bugs in nginx's C codebase.
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The proxy supports multiple domains from initial release (git.alk.dev and
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alk.dev), with per-domain host-based routing and a single multi-domain SAN
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certificate via ACME.
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## Architecture Documents
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| Document | Status | Description |
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|----------|--------|-------------|
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| [overview.md](overview.md) | Draft | Vision, scope, crate dependencies, exports |
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| [proxy.md](proxy.md) | Draft | Reverse proxy handler, request flow, header injection |
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| [tls.md](tls.md) | Draft | TLS termination, ACME, manual certs, SNI |
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| [config.md](config.md) | Draft | TOML config format, static/dynamic split, ArcSwap reload |
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| [operations.md](operations.md) | Draft | Rate limiting, logging, health check, systemd, shutdown |
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## ADR Table
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| ADR | Title | Status |
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|-----|-------|--------|
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| [001](decisions/001-rust-axum.md) | Rust with Axum | Accepted |
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| [002](decisions/002-custom-proxy-handler.md) | Custom Proxy Handler | Accepted |
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| [003](decisions/003-toml-config.md) | TOML Configuration Format | Accepted |
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| [004](decisions/004-rustls-acme.md) | ACME-Primary Certificate Management | Accepted |
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| [005](decisions/005-tokio-rustls-direct.md) | tokio-rustls Directly, Not axum-server | Accepted |
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| [006](decisions/006-rate-limiting-approach.md) | Token Bucket Rate Limiting | Accepted |
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| [007](decisions/007-custom-log-format.md) | Custom Structured Log Format | Accepted |
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| [008](decisions/008-static-dynamic-config-split.md) | Static/Dynamic Config Split with ArcSwap | Accepted |
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| [009](decisions/009-signal-handling.md) | Signal Handling Strategy | Accepted |
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| [010](decisions/010-multi-site-phase1.md) | Multi-Site Support in Phase 1 | Accepted |
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| [011](decisions/011-multi-domain-tls.md) | Multi-Domain TLS Configuration | Accepted |
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| [012](decisions/012-cipher-suite-restriction.md) | Restrict Cipher Suites to nginx Scope | Accepted |
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| [013](decisions/013-health-check-port.md) | Health Check on Separate Local Port | Accepted |
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| [014](decisions/014-unix-socket-reload.md) | Unix Domain Socket Config Reload API | Accepted |
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| [015](decisions/015-per-site-timeouts.md) | Per-Site Upstream Timeouts with Defaults | Accepted |
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| [016](decisions/016-explicit-bind-address.md) | Explicit Bind Address Requirement | Accepted |
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| [017](decisions/017-upstream-connection-defaults.md) | Upstream Connection Defaults | Accepted |
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| [018](decisions/018-body-size-limit.md) | Request Body Size Limit | Accepted |
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| [019](decisions/019-multi-config-listeners.md) | Multi-Config Listener Support | Accepted |
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| [020](decisions/020-container-deployment.md) | Container Deployment Model | Accepted |
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| [021](decisions/021-x-forwarded-for-edge-proxy.md) | X-Forwarded-For Edge Proxy Model | Accepted |
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| [022](decisions/022-health-check-scope.md) | Health Check Scope — Local Port and Admin Socket Only | Accepted |
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## Open Questions
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See [open-questions.md](open-questions.md) for the full tracker.
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| OQ | Question | Priority | Status |
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|----|----------|----------|--------|
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| ~~OQ-01~~ | ~~Should cipher suites be restricted beyond rustls defaults?~~ | ~~medium~~ | **resolved** (ADR-012) |
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| ~~OQ-02~~ | ~~What log format should fail2ban consume?~~ | ~~high~~ | **resolved** (ADR-007) |
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| ~~OQ-03~~ | ~~Should the health check endpoint be on a separate port?~~ | ~~low~~ | **resolved** (ADR-013) |
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| ~~OQ-04~~ | ~~Config reload: SIGHUP only or also Unix socket API?~~ | ~~low~~ | **resolved** (ADR-014) |
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| ~~OQ-05~~ | ~~Should the proxy bind to multiple addresses?~~ | ~~low~~ | **resolved** (single bind_addr sufficient) |
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| ~~OQ-06~~ | ~~Should upstream timeouts be configurable per-site?~~ | ~~low~~ | **resolved** (ADR-015) |
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| ~~OQ-07~~ | ~~Should per-site TLS overrides be supported for mixed ACME/manual domains?~~ | ~~low~~ | **resolved** (ADR-019) |
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| ~~OQ-08~~ | ~~Should `/health` use a less common path to avoid upstream collision?~~ | ~~medium~~ | **resolved** (ADR-022: no `/health` route on main listener) |
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| ~~OQ-09~~ | ~~How should `upstream_connect_timeout_secs` be enforced?~~ | ~~medium~~ | **resolved** (implementation gap — ADR-015 already decides this) |
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| ~~OQ-10~~ | ~~Should ACME contact email be a required config field?~~ | ~~high~~ | **resolved** (already specified in config.md; implementation bug C2) |
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| ~~OQ-11~~ | ~~How should `X-Forwarded-Proto` be derived per-listener?~~ | ~~medium~~ | **resolved** (hardcoded `https` is correct for TLS-terminating proxy) |
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| ~~OQ-12~~ | ~~Should request access logging be mandatory or optional?~~ | ~~high~~ | **resolved** (mandatory, always-on per operations.md) |
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## Document Lifecycle
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| Status | Meaning | Transitions |
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|--------|---------|-------------|
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| `draft` | Under active development. May change significantly. | → `reviewed` when open questions are resolved |
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| `reviewed` | Architecture is final. Implementation may begin. Changes require review. | → `stable` when implementation is complete |
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| `stable` | Locked. Changes require review and may warrant an ADR. | → `deprecated` when superseded |
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| `deprecated` | Superseded. Kept for reference. | Removed when no longer referenced | |