[aw-failures] [aw] P0: Smoke Gemini — Gemini CLI proxy architecture blocks all agent traffic (localhost:8080 not reachable)

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Problem

Smoke Gemini (Google Gemini CLI engine) fails on every run because the Gemini CLI internally routes all requests through localhost:8080 as its MCP/proxy gateway — an address that the agentic workflow firewall blocks. This results in a 94% block rate (295/315 requests) and agent job failure.

Affected Workflow & Run

• Workflow: Smoke Gemini
• Engine: Google Gemini CLI
• Failing run: §25263690512 (2026-05-03, firewall v0.25.35)
• Trigger branch: copilot/bump-firewall-version-to-v0-25-35

Evidence

Firewall block breakdown:

Domain	Requests blocked
localhost:8080	279
172.30.0.30:10003	15
unknown	1
Total blocked	295 / 315 (94%)
Only allowed	play.googleapis.com:443 (20)

• blocked_request_at_cap: true — the blocked request counter was capped
• Client error artifacts generated: gemini-client-error-Turn.run-sendMessageStream (50KB), gemini-client-error-generateJson-api (34KB)
• Failure stage: agent job (5.6m) → FAILURE; cascaded detection and safe_outputs as skipped

Root Cause

Gemini CLI's architecture routes all network traffic (including MCP calls) through a local proxy at localhost:8080. The agentic workflow firewall blocks all loopback addresses (127.0.0.0/8) that are not explicitly allow-listed. This is a fundamental architectural incompatibility: as long as the firewall blocks localhost:8080, the Gemini engine cannot operate.

The secondary address 172.30.0.30:10003 appears to be the container's internal proxy IP — also blocked.

Proposed Remediation

Two viable approaches:

1. Firewall allow-list (lower effort): Add localhost:8080 and/or 172.30.0.30:10003 to the firewall's allow-list for the Gemini engine container. Risk: may weaken isolation.
2. Reconfigure Gemini CLI proxy (preferred): Configure the Gemini CLI to route MCP traffic through an external/allowed endpoint instead of the loopback proxy. This preserves firewall integrity.

Additionally, investigate why 172.30.0.30:10003 is being targeted — this may be a separate MCP gateway that needs to be routed differently.

Success Criteria

• Smoke Gemini run completes with conclusion: SUCCESS
• Firewall block rate drops below 10%
• No gemini-client-error artifacts generated

Parent: #29851

Generated by [aw] Failure Investigator (6h) · ● 448.8K · ◷

• expires on May 10, 2026, 1:32 AM UTC