feat: wire plumbing — real query data, ProxyError, streaming body limit by yairfalse · Pull Request #59 · false-systems/rauta

yairfalse · 2026-03-21T00:29:16Z

Summary

Real query data: rauta status, rauta routes list, rauta diagnose now return live gateway state instead of empty placeholders
ProxyError enum: Eliminates e.starts_with("TIMEOUT:") string matching — errors are now typed with proper HTTP status codes
Streaming body limit: http_body_util::Limited enforces 10MB cap during reading, not after full collection (prevents OOM)

What changed

Router — new list_routes() method returns Vec<RouteSnapshot> with backend health scores and draining status

CircuitBreakerManager — new snapshot_all() and open_count() for iterating all breakers via ArcSwap

RateLimiter — new snapshot_all(), exhausted_count(), TokenBucket::capacity(), TokenBucket::refill_rate()

LocalGatewayQuery — fully wired:

snapshot() reports real open_circuits and exhausted_rate_limiters
list_routes() / list_circuit_breakers() / list_rate_limiters() return real data with filtering
diagnose() feeds real route/CB/RL data to the diagnostics engine

ProxyError — replaces Result<..., String> in forward_to_backend and handle_request:

ProxyError::Timeout → 504
ProxyError::BackendError → 502
ProxyError::BodyTooLarge → 413
From<String> impl for backward compat

Body streaming — http_body_util::Limited::new(body, MAX_BODY_SIZE) wraps the body stream, aborting read at 10MB instead of buffering everything first

Test plan

220 tests pass across 5 crates
clippy clean, fmt clean
Manual: curl localhost:9091/api/v1/status shows real open_circuits count
Manual: curl localhost:9091/api/v1/routes shows configured routes

🤖 Generated with Claude Code

Wire LocalGatewayQuery to return real data: - Router.list_routes() exposes all routes as RouteSnapshot with backend health scores and draining status - CircuitBreakerManager.snapshot_all() and open_count() iterate the ArcSwap breaker map - RateLimiter.snapshot_all() and exhausted_count() iterate the ArcSwap bucket map, expose TokenBucket.capacity() and refill_rate() - LocalGatewayQuery.snapshot() now reports real open_circuits and exhausted_rate_limiters counts - list_routes/list_circuit_breakers/list_rate_limiters support filtering and return sorted results - diagnose() passes real route/CB/RL data to the diagnostics engine Wire ProxyError through the proxy (eliminates string matching): - forward_to_backend returns Result<..., ProxyError> instead of String - Timeout errors use ProxyError::Timeout (not "TIMEOUT:" prefix) - Body limit errors use ProxyError::BodyTooLarge - record_request_metrics uses e.status_code()/e.status_str() instead of e.starts_with("TIMEOUT:") - error_to_response takes ProxyError, maps via status_code() - From<String> impl provides backward compat for legacy error sites Streaming body limit (prevents OOM): - Use http_body_util::Limited to enforce 10MB cap during streaming - Body reading stops at the limit instead of collecting everything first - Returns 413 (ProxyError::BodyTooLarge) without buffering oversized data Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Copilot

Pull request overview

This PR wires the control-plane “query” surfaces (status/routes/diagnose) to real in-process gateway state, replaces stringly-typed proxy errors with a structured ProxyError, and enforces request body size limits while streaming to prevent buffering large payloads.

Changes:

Add snapshot/list APIs on Router, CircuitBreakerManager, and RateLimiter to expose live route/CB/RL state to admin/CLI/MCP queries.
Introduce ProxyError with HTTP status mapping, and propagate it through request handling/forwarding/metrics.
Enforce a 10MB request body cap during streaming reads using http_body_util::Limited.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
control/src/proxy/router.rs	Adds `list_routes()` to expose configured routes as agent-api snapshots including backend draining/health hints.
control/src/proxy/request_handler.rs	Switches handler pipeline to `ProxyError`, updates metrics/error mapping, and keeps retry logic working under typed errors.
control/src/proxy/rate_limiter.rs	Exposes token bucket capacity/refill rate and adds `snapshot_all()` + `exhausted_count()` for admin queries.
control/src/proxy/forwarder.rs	Uses `ProxyError` and enforces streaming body size limit with `http_body_util::Limited`.
control/src/proxy/circuit_breaker.rs	Adds `snapshot_all()` + `open_count()` for admin status/diagnostics.
control/src/error.rs	Introduces `ProxyError` enum with status mapping and legacy `From<String>` conversion.
control/src/admin/local_query.rs	Replaces placeholder query responses with live router/CB/RL data and adds filtering/sorting.

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Copilot · 2026-03-21T00:44:57Z

+            let err_str = e.to_string();
+            if err_str.contains("length limit exceeded") {


Body-size limit detection is currently based on e.to_string().contains("length limit exceeded"), which is brittle and may break if the error message changes. Prefer matching on the concrete error type/variant returned by http_body_util::Limited (or using an API like is_limit_exceeded if available) rather than string inspection.

Suggested change

let err_str = e.to_string();

if err_str.contains("length limit exceeded") {

// Detect body-size limit violations using the concrete error type

// produced by `http_body_util::Limited`, rather than inspecting

// the error message string.

if e.is::<http_body_util::LengthLimitError>() {

Fixed in 589fa15 — now uses e.is::<http_body_util::LengthLimitError>() for type-safe detection instead of string matching.

Copilot · 2026-03-21T00:44:57Z

+                    "Request body exceeded size limit"
+                );
+                return ProxyError::BodyTooLarge {
+                    size: MAX_BODY_SIZE + 1,


ProxyError::BodyTooLarge is constructed with size: MAX_BODY_SIZE + 1, which is not the actual received size and can be misleading in logs/API responses. If the limiting layer doesn’t expose the real size, consider reporting size: MAX_BODY_SIZE (or omitting/setting to 0/None) and keeping max as the authoritative limit.

Suggested change

size: MAX_BODY_SIZE + 1,

size: MAX_BODY_SIZE,

Fixed in 589fa15 — now reports size: 0 since the actual received size is unknown when streaming was aborted at the limit. The max field still shows the configured cap.

Copilot · 2026-03-21T00:44:58Z

+        Err(ref e) => {
+            let status_code = e.status_code();
+            let status_str = e.status_str();

            HTTP_REQUESTS_TOTAL


With ProxyError now carrying client/proxy-side conditions (e.g., BodyTooLarge = 413), treating every Err(e) uniformly as a backend error can skew metrics/health. Consider branching on the ProxyError variant here so client-side errors don’t get counted the same way as backend failures (and aren’t later attributed to backend health/circuit breaker).

Fixed in 589fa15 — BodyTooLarge errors now skip record_backend_response and circuit_breaker.record_failure. Only backend-originated errors (Timeout, BackendError) affect health metrics.

Copilot · 2026-03-21T00:44:58Z

+/// Allow `?` on String errors (legacy compatibility during migration)
+impl From<String> for ProxyError {
+    fn from(s: String) -> Self {
+        ProxyError::BackendError { message: s }


From<String> for ProxyError maps all legacy String errors to BackendError (502). This can misclassify internal/proxy errors that still use String with ?, leading to incorrect HTTP status/metrics. Consider removing this blanket conversion once migration is complete, or narrowing it (e.g., only for known backend-connection strings) and updating call sites to construct the correct ProxyError variant explicitly.

Suggested change

/// Allow `?` on String errors (legacy compatibility during migration)

impl From<String> for ProxyError {

fn from(s: String) -> Self {

ProxyError::BackendError { message: s }

/// Allow `?` on String errors (legacy compatibility during migration).

/// Generic `String` errors are treated as internal/filter failures (500),

/// not as backend connection errors (502), to avoid misclassification.

impl From<String> for ProxyError {

fn from(s: String) -> Self {

ProxyError::FilterError { message: s }

Added transitional docs in 589fa15. The From<String> impl is explicitly marked as a migration shim with a note that callers should construct specific variants directly. Will be removed once all error sites are migrated.

Copilot · 2026-03-21T00:44:58Z

        let retry_req = match retry_builder.body(Full::new(Bytes::new())) {
            Ok(r) => r,
            Err(e) => {
-                last_result = Err(format!("Failed to build retry request: {}", e));
+                last_result = Err(ProxyError::BackendError {
+                    message: format!("Failed to build retry request: {}", e),


When rebuilding the retry request, ensure the retry URI preserves the original request’s query string. Currently the retry path construction earlier in this block uses path (from req.uri().path()), so retries can silently drop ?query=... parameters and change GET/HEAD semantics.

Fixed in 589fa15 — retry URI now uses path_and_query (from req.uri().path_and_query()) instead of just path. Query parameters like ?foo=bar are preserved across retries.

- Use LengthLimitError type check instead of string matching for body limit detection (fixes brittle e.to_string().contains() pattern) - Report size: 0 in BodyTooLarge since actual size is unknown when streaming was aborted at the limit - Don't count BodyTooLarge (client error) against backend health/circuit breaker — only backend-originated errors affect health metrics - Preserve query string in retry URIs (was silently dropping ?query=...) - Add transitional docs to From<String> for ProxyError Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

yairfalse requested a review from Copilot March 21, 2026 00:38

Copilot started reviewing on behalf of yairfalse March 21, 2026 00:38 View session

Copilot AI reviewed Mar 21, 2026

View reviewed changes

yairfalse merged commit 56d8ca4 into main Mar 21, 2026
2 checks passed

yairfalse deleted the feat/wire-plumbing branch March 21, 2026 15:58

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feat: wire plumbing — real query data, ProxyError, streaming body limit#59

feat: wire plumbing — real query data, ProxyError, streaming body limit#59
yairfalse merged 2 commits into
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		let err_str = e.to_string();
		if err_str.contains("length limit exceeded") {

-            let err_str = e.to_string();
-            if err_str.contains("length limit exceeded") {
+            // Detect body-size limit violations using the concrete error type
+            // produced by `http_body_util::Limited`, rather than inspecting
+            // the error message string.
+            if e.is::<http_body_util::LengthLimitError>() {

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yairfalse commented Mar 21, 2026

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