* fix(proxy): harden MITM proxy reliability and scale for bulk installs
Deep-dive analysis of dropped connections during large installs (5000+
packages with concurrent downloads) surfaced three issues, each verified
with a reproduction test before fixing.
1. Transient upstream errors tore down whole keep-alive tunnels.
goproxy returns false (closing the entire MITM client tunnel) when a
single upstream round-trip errors. Under load, CDN-fronted registries
(e.g. Cloudflare for registry.npmjs.org) intermittently reset
connections, so one transient reset dropped a pooled keep-alive socket
and surfaced to the package manager as ECONNRESET / "socket hang up".
Fix: route upstream round-trips through a resilient round tripper that
retries idempotent, body-less requests with bounded linear backoff,
absorbing transient resets and keeping the tunnel alive. A reproduction
test shows the tunnel count drop from 3 to 1 across a transient failure.
2. Head-of-line amplification against the external analysis service.
Concurrent requests for the same package version each issued their own
gRPC call. Fix: de-duplicate in-flight analyses with singleflight so a
burst of identical requests collapses into one upstream call.
3. Per-request goproxy verbose logging on the hot path.
proxy.Verbose was always on, formatting several log lines per request
even when discarded below debug level. Fix: enable goproxy verbose
logging only when PMG runs at debug level.
Note: the hypothesis that the http.Server Read/WriteTimeout leaks onto
hijacked CONNECT tunnels was investigated and disproven (Go clears the
deadlines on Hijack); the behavioral guard tests for long-lived
connections and slow transfers are retained.
* fix: Type assertion error handling
---------
Co-authored-by: Claude <noreply@anthropic.com>
* feat: Add dependency cooldown for npm packages
Strip recently-published package versions from npm registry metadata
responses so npm's resolver naturally falls back to older versions.
Overrides the Accept header to force full packument responses (which
include the "time" field needed for publish-date checks).
Reports cooldown blocks only when all versions are stripped (remaining == 0),
matching npm's --min-release-age behavior for silent fallback.
* fix: Report oldest version in cooldown block (shortest wait)
When all versions are blocked by cooldown, report the oldest version
since it exits the cooldown window first — giving the user the
shortest wait time instead of the longest.
* fix: Handle resp.Body.Close error return for errcheck linter
* test: Add dependency cooldown assertions to template config tests
* fix: config template for dependency cooldown
* fix: Prevent npm from caching cooldown-stripped metadata responses
* fix: Restore body on ReadAll failure and log Close errors in response modifier
* fix: Close response body before replacing to prevent connection leak
* fix: Correct daysLeft ceiling math and update ContentLength on error recovery
* fix: Clear Status on status code change and update ContentLength in modifier error path
* refactor: address review comments on dependency cooldown PR
- Make NpmCooldownHandler and constructor package-private
- Pass cooldown days as parameter instead of reading config internally
- Convert standalone functions to methods on npmCooldownHandler
- Set Accept-Encoding: identity to prevent gzip responses breaking JSON parsing
- Return 503 with descriptive message when upstream body read fails
* fix: log errors in stripCooldownVersions instead of swallowing them
* fix: Config preserve fallback defaults
* fix: Code review fixes
* fix: correct cooldown tip to show wait time instead of incorrect trusted_packages advice
* fix: prevent integer overflow in cooldown duration calculation with large days values
* refactor: deduplicate CooldownBlock into internal/models, fix misleading variable names
- Move CooldownBlock struct to internal/models to eliminate duplication
between proxy/interceptors and internal/ui packages
- Simplify proxy_flow.go by using direct assignment instead of field copy
- Rename latestStripped/latestDate to oldestVer/oldestDate for clarity
* fix: Dependency Cooldown Check Encapsulation (#207)
* fix: Encapsulate cooldown check
* feat: Add --skip-dependency-cooldown override
* fix: Code review fixes
---------
Co-authored-by: Abhisek Datta <abhisek.datta@gmail.com>
When users have HTTP_PROXY/HTTPS_PROXY set in their shell (e.g. corporate
proxy), PMG's upstream transport routes all traffic through that external
proxy — including requests to localhost/127.0.0.1. The external proxy
cannot reach the user's loopback, causing EFAULT/ConnectionRefused errors.
This adds loopback bypass in two places:
- Proxy upstream transport skips external proxy for localhost/127.0.0.1/::1
- Child process env gets NO_PROXY so proxy-aware libs (axios) skip PMG's
proxy for loopback addresses
Fixes#193
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
