* fix(proxy): reuse upstream connections for OpenCode API requests
`createProxyMiddleware` was constructed without an `agent`, so `http-proxy`
fell back to `agent: false`. That disables connection pooling and forces
`Connection: close` on every proxied request, consuming one ephemeral port
per request.
Measured against a real `opencode serve` instance, 200 sequential requests
through the proxy created 201 TIME_WAIT entries (1.005 ports/request). With
a keep-alive agent the same load creates 0.
On macOS the ephemeral range is 16,384 ports and TIME_WAIT lasts 30s, so
sustained traffic around 546 req/sec exhausts the pool — after which every
process on the host fails to open outbound connections with EADDRNOTAVAIL.
`maxSockets: Infinity` preserves the unbounded concurrency of `agent: false`,
so this changes connection reuse only, not request throughput.
Partially addresses #2915.
* fix(proxy): derive proxy agent class from the target scheme
Addresses review feedback on #2916. The first commit created an
unconditional `http.Agent`, which regresses external OpenCode servers
configured over https via `OPENCODE_HOST` (accepted by env-config.js).
http-proxy dispatches through `https.request` when the target protocol is
`https:` (http-proxy/lib/http-proxy/passes/web-incoming.js:126), and
`http.Agent#createConnection` is plain `net.createConnection` — so an
http.Agent would open a plaintext socket to a TLS port and fail every
proxied request. `agent: false` previously worked for both schemes.
`createOpenCodeProxyAgent(target)` now returns an `https.Agent` for https
targets and an `http.Agent` otherwise, derived once from
`resolveProxyTarget()` at registration so the single shared instance is
preserved across `apiProxy` and `interactiveOAuthProxy`.
Guarded in both test layers, verified to fail when the selection is
reverted to an unconditional http.Agent. `https.Agent` extends
`http.Agent`, so the http cases assert `not.toBeInstanceOf(https.Agent)`.
* Round 2: fix: resolve the proxy agent lazily so cold starts honor https
Addresses the round-2 blocker on #2916. Deriving the agent class at
registration is too early: startup-pipeline-runtime.js calls setupProxy()
(line 104) before bootstrapOpenCodeAtStartup() (line 141), so on a fresh
process state.openCodePort is null, buildOpenCodeUrl() throws
(network-runtime.js:86-88), and resolveProxyTarget() returns the http
loopback fallback. An external server configured via OPENCODE_HOST=https://
only appears on state.openCodeBaseUrl after bootstrap, so it was still
getting a plain http.Agent — the regression the previous commit intended
to fix.
`agent` is now a getter backed by a per-scheme memoizing resolver.
http-proxy-middleware rebuilds per-request options with
`Object.assign({}, this.proxyOptions)` in prepareProxyRequest, which invokes
getters, so resolution happens at request time while still yielding one
shared pool per scheme.
Tests now model the production ordering — registration while the port is
null and buildOpenCodeUrl throws, then an https base URL appearing after
bootstrap — and fail against the eager implementation. A behavioral test
pins the http-proxy-middleware option re-read the fix depends on, so a
library change that froze options would fail loudly instead of silently
regressing https targets.
The resolver is module-private; `bun run dead-code` flagged it as an
unused export when it was exported.
* Round 3: docs(changelog): note upstream connection reuse under [Unreleased]
Repo precedent adds [Unreleased] bullets for comparable proxy/stability
fixes (1.18.4 Stability, 1.9.3 Reliability/Proxy). Non-blocker raised in
review on #2916.
* Round 3: docs(changelog): use repo-standard 'behavior' spelling
* Round 4: docs(changelog): don't imply a restart is the only recovery
The ephemeral port pool drains on its own once the exhausting traffic
stops (TIME_WAIT expiry), so a restart is sufficient but not necessary.
Optional nit raised in review on #2916.
* Round 5: fix: construct the proxy agent through one factory; widen the pool
Review found the https branch was mutation-uncovered: the resolver
re-implemented agent construction inline instead of calling the exported
`createOpenCodeProxyAgent(target)`, so replacing its https branch with
`new https.Agent()` — dropping OPENCODE_AGENT_OPTIONS, and with it
keep-alive — left the entire suite green. Since `createOpenCodeProxyAgent`
also had no production callers, its four tests were pinning dead code.
Delegating collapses both: the factory is now the single construction
path, and the mutation fails 2 tests including the live resolver path.
Also from review:
- maxFreeSockets 32 -> 256 (Node's own default). The lower cap evicted
pooled sockets under concurrency, reintroducing the churn this agent
exists to prevent: at 64 concurrent requests it left 303 sockets in
TIME_WAIT versus 0 at 256.
- Added `timeout` to OPENCODE_AGENT_OPTIONS. Free-socket eviction is
governed by agent.options.timeout, which was unset, so idle sockets
persisted until the peer closed them. `keepAliveMsecs` is the TCP probe
delay, not the idle lifetime.
- resolveProxyTarget() now checks openCodePort before calling
buildOpenCodeUrl instead of relying on it throwing. The port is nulled
on several runtime paths (health-check failure, failed restart), so a
degraded OpenCode made every proxied request pay for a thrown-and-caught
exception — and the getter added a second call per request.
- Test fixtures use :4096 rather than :443; WHATWG URL elides the default
port, so parseInt('') is NaN and env-config rejects that host. The
fixtures modeled a state that cannot reach production.
- The getter-read assertion is now exact (0 at construction, 1, then 2)
rather than >= 2, which would have passed if the getter were read twice
at construction and never per-request.
- listen() rejects on 'error' and servers start inside try/finally, so a
bind failure fails the test instead of hanging to timeout.
Aaron Hogue
7611076436