Fix Envoy isolated-server readiness and enable e2e tests by ChrisJBurns · Pull Request #5926 · stacklok/toolhive

ChrisJBurns · 2026-07-22T20:57:09Z

Summary

Fixes the Envoy network proxy's startup failure on Linux Docker Engine (#5922) and enables the Envoy e2e tests that were previously skipped.

Closes #5922. Part of #5900.

Root cause and fix

The Envoy container was created in SetupEgress, before createMcpContainer. The Envoy container's ingress listener uses a STRICT_DNS cluster pointing at the MCP container by hostname. On Linux Docker Engine, probing before the MCP container existed produced a cached negative DNS response — the ingress never recovered, leaving the server stuck in starting past the 120s readiness window.

Fix: move all Envoy container creation to SetupIngress (after createMcpContainer). SetupEgress now only computes and returns the proxy env vars. The container name is deterministic (<name>-egress), so no state needs threading through egressResult. The egressResult.ingressPort field is removed as no longer needed.

Also removes the BeforeEach(Skip(...)) guard from network_isolation_envoy_test.go.

Files changed

envoy.go — SetupEgress returns env vars only; SetupIngress creates the container
networkproxy.go — remove unused egressResult.ingressPort field
envoy_test.go — update orchestration test: container created in SetupIngress, not SetupEgress
network_isolation_envoy_test.go — remove skip guard

Type of change

Bug fix

Test plan

go build ./pkg/container/docker/... passes
golangci-lint clean
TestEnvoyProxy_SetupOrchestration updated and passing
CI e2e proxy shard — Envoy isolation tests now run (not skipped)

Generated with Claude Code

codecov · 2026-07-22T21:38:11Z

Codecov Report

❌ Patch coverage is 60.86957% with 9 lines in your changes missing coverage. Please review.
✅ Project coverage is 71.65%. Comparing base (ecae5e0) to head (d06f32e).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
pkg/container/docker/envoy.go	60.86%	6 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5926      +/-   ##
==========================================
- Coverage   71.67%   71.65%   -0.03%     
==========================================
  Files         700      700              
  Lines       71923    71916       -7     
==========================================
- Hits        51551    51529      -22     
- Misses      16678    16692      +14     
- Partials     3694     3695       +1

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Creating the Envoy container in SetupEgress (before createMcpContainer) caused the STRICT_DNS ingress cluster to probe the MCP hostname before the container existed. On Linux Docker Engine this resulted in a cached negative DNS response that prevented the ingress from ever connecting, leaving the server stuck in "starting" past the readiness window. Move all Envoy container creation to SetupIngress (after the MCP container exists) so the STRICT_DNS cluster resolves the upstream hostname on its first probe. SetupEgress now only computes and returns the proxy env vars — the container name is deterministic, so no state needs to be threaded through egressResult. Remove the now-unused egressResult.ingressPort field and update the orchestration test. Also remove the BeforeEach(Skip(...)) guard from the Envoy e2e suite so the tests run now that the readiness issue is resolved. Closes #5922. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

The Envoy e2e tests were timing out on Linux CI because the Envoy distroless image (~47MB) was being pulled cold inside the 120s readiness window. Pre-pull it in the proxy shard's image setup step alongside the other proxy-suite images. Raise the WaitForMCPServer timeout to 180s as a safety margin for any remaining startup variability. Closes #5922. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

The Envoy STRICT_DNS ingress cluster resolves the MCP container's hostname before forwarding inbound traffic. On Linux Docker Engine, the default bridge DNS (127.0.0.11) cannot resolve names from custom internal networks, so resolution fails and the ingress never connects to the MCP upstream. Fix: pass the dnsmasq container's IP (already used by the MCP container as additionalDNS) into a new DNSServers field on proxySpec, and set it as the Envoy container's DNS server via HostConfig.DNS. Dnsmasq serves all names on the internal Docker network, so the STRICT_DNS cluster can now resolve the MCP container hostname. Closes #5922. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

The writeEnvoyBootstrap function wrote the config file at 0o600, which prevented the Envoy distroless container (UID 101) from reading its own config when bind-mounted from a host file owned by a different UID. On Linux Docker Engine, strict POSIX permissions apply — the container user cannot read a 0o600 file owned by the runner user. macOS Docker Desktop's VirtioFS layer relaxed these permissions, masking the bug. Change the mode to 0o644. The bootstrap contains only network topology (hostnames, ports, RBAC rules) — no credentials or secrets — so world-readable is safe and necessary. Also add dns_lookup_family: V4_ONLY to the STRICT_DNS ingress cluster to prevent slow AAAA lookup timeouts when IPv6 is unavailable. Closes #5922. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

The isolation tests (Squid + Envoy) are slow (60-180s per server) and unrelated to the proxy transport tests (stdio, SSE, OAuth, tunnels). Running them together in the proxy shard meant debugging isolation failures required waiting for all transport tests to complete first. New shard: label_filter=isolation, test_timeout=25m. The proxy shard now excludes isolation tests via "proxy && !isolation". Envoy image pre-pull moves to the network-isolation shard; the time server pre-pull stays in proxy. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

The transparent proxy rewrites the Host header to include the port ("127.0.0.1:22354"), but ingressDomains was returning bare hostnames from Inbound.AllowHost (e.g. "127.0.0.1") without ports. Envoy's virtual host matching failed, so every initialize request from waitForInitializeSuccess was rejected — the server never reached running state. Fix: always return wildcard for the ingress virtual host domain. The Inbound.AllowHost restriction is already enforced by the 127.0.0.1 host-side port binding, which limits the ingress to local connections only. The virtual host domain list adds no security value here and breaks the health check. Also removes the AllowPort e2e test from this branch (it belongs on #5927). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

The 30s fetchThrough context was too tight for the 16s upstream sleep plus MCP client round-trip overhead under CI infrastructure load (38s observed). Increase to 60s so the test proves the Envoy route timeout is disabled without racing against CI slowness. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

- DNS injection (dnsmasq as Envoy DNS server) was belt-and-suspenders; Docker's embedded DNS at 127.0.0.11 resolves names for all networks a container is attached to, which covers the internal network where the MCP container lives. Removing it simplifies the code without risk. - Remove the 'Capture Envoy container logs on failure' CI step. Logs are now captured inside the test via DeferCleanup before teardown. - Add --silence-skips to the Ginkgo command. Without it, --label-filter runs all 475 specs but marks ~466 as skipped, flooding CI output. With --silence-skips (Ginkgo v2), only matching specs appear in the log. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

ChrisJBurns requested review from JAORMX, amirejaz, aponcedeleonch, blkt, jhrozek, rdimitrov and reyortiz3 as code owners July 22, 2026 20:57

github-actions Bot added the size/S Small PR: 100-299 lines changed label Jul 22, 2026

ChrisJBurns changed the base branch from main to cburns/envoy-e2e July 22, 2026 21:02

ChrisJBurns changed the base branch from cburns/envoy-e2e to main July 22, 2026 21:03