feat: basic envoy tunnel impl

[MasterPtato]

Description

Please include a summary of the changes and the related issue. Please also include relevant motivation and context.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

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[MasterPtato]

• chore: remove global epoxy contention #4554
• feat: native SQLite backend via napi-rs with KV channel protocol #4496
• feat: actor query in gateway #4553
• feat: add sleep and reschedule endpoints for actors #4556
• fix: optimize e2e actor path #4551
• feat(pb): actor v1 to v2 migration #4548
• feat(envoy-client): fully flesh out tunnel impl #4547
• feat: basic rivetkit impl #4544
• feat: basic envoy tunnel impl #4534 👈 (View in Graphite)
• chore: envoy client #4521 : 1 other dependent PR (#4531 )
• feat(pb): actors v3 #4463
• feat(ups): implement queue subs #4486
• feat(cache): add in flight deduping #4459
• fix(cache): clean up lib #4457
• fix(config): allow configuring topo dcs via map, fix pg ssl mode config #4456
• fix(api): dont 500 on cross dc response #4449
• chore: update byte units on frontend #4444
• fix: runner alloc idx logic, api auth for actor get #4443
• main

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commit: da489fa

[claude]

PR Review: feat: basic envoy tunnel impl

Good foundational work on the HTTP tunnel implementation. There are a few bugs and design concerns worth addressing before merging.

---

Bugs

1. Wrong field name for max payload check (tunnel.ts)

ctx.protocolMetadata?.maxPayloadSize should be ctx.protocolMetadata?.maxResponsePayloadSize. The field added to ProtocolMetadata (in both v1.bare and envoy-protocol/src/index.ts) is maxResponsePayloadSize. As written, the comparison is always number > undefined which is false in JavaScript, silently disabling the payload size limit.

2. Map lookup by array key always fails (actor.ts, tunnel.ts)

// This pattern breaks -- Map uses reference equality for object keys
pendingRequests: new Map<[protocol.GatewayId, protocol.RequestId], PendingRequest>()

map.get([gatewayId, requestId]) will never match a map.set([gatewayId, requestId], ...) entry because each array literal is a distinct object. A string composite key like ${gatewayId}:${requestId} would work correctly. This affects all request-chunk and request-abort lookups in both actor.ts and tunnel.ts.

3. requestToActor is never populated (tunnel.ts)

handleRequestStart forwards the request to the actor but never calls ctx.requestToActor.set(...). As a result, handleRequestChunk and handleRequestAbort will always find actorId === undefined and return early without processing chunks.

4. Streaming request body: initial body bytes are discarded (actor.ts)

In the streaming path of request-start, a ReadableStream is created and its controller is stored in pendingRequests, but the initial msg.req.body bytes from the RequestStart message are passed directly (not enqueued into the stream). Those bytes are effectively discarded -- the Request is constructed with the stream as its body, which starts empty until chunks arrive.

5. SIGTERM/SIGINT copy-paste bug (test-envoy/src/index.ts)

Both SIGTERM and SIGINT handlers log "received SIGTERM". The SIGINT handler should log "received SIGINT".

---

Design Concerns

6. startEnvoy can hang indefinitely

startEnvoy now awaits startRx.changed(), which only resolves once ToEnvoyInit is received. If init is never received (network issue, auth failure, etc.), the call hangs forever. A timeout should wrap this await.

7. Errors from spawn(sendResponse(...)) are silently dropped (actor.ts)

The spawn call that invokes sendResponse doesn't handle errors. If sendResponse throws (e.g., body too large), the error is lost and the request never receives a response. Consider catching the error and sending an error response instead.

8. Oversized body throws instead of returning an error response (tunnel.ts)

throw new Error("Response body too large") propagates up and gets swallowed by the unhandled spawn. Prefer sending a 413 Payload Too Large response so the caller gets actionable feedback.

9. v1.bare modified instead of adding a new schema version

Per CLAUDE.md: "Never modify an existing published *.bare runner protocol version unless explicitly asked to do so. Add a new versioned schema instead." Adding maxResponsePayloadSize to v1.bare violates this. A v2.bare (or appropriate next version) should carry the new field.

---

Minor

• await envoy?.shutdown() (test-envoy/src/index.ts): shutdown() returns void, so the await is a no-op. Remove it.
• Import inconsistency (tunnel.ts): Uses @/context.js (path alias) while all other envoy-client files use relative imports. Align with the existing convention.
• clientMessageIndex in PendingRequest is unused -- Stored but never incremented or validated, so chunk ordering/deduplication silently does nothing.
• TODO: Actor v2 comment (delete.rs): Link to an issue number so this doesn't get lost.
• test-envoy/src/log.ts appears to be duplicated from test-runner/src/log.ts. Consider extracting to a shared package.

[NathanFlurry]

Merge activity

• Apr 5, 11:11 AM UTC: A user started a stack merge that includes this pull request via Graphite.
• Apr 5, 11:30 AM UTC: Graphite rebased this pull request as part of a merge.
• Apr 5, 11:31 AM UTC: @NathanFlurry merged this pull request with Graphite.