---
plan: 03-01
phase: 03-ssh-execution
status: complete
completed: 2026-03-23
requirements-completed: [EXEC-03]
---

# 03-01 Summary: SSHConnectionManager

## What Was Built

`vmcluster_mcp/exec/ssh.py` — SSH connection manager with per-node caching and transparent reconnect. Foundation for all Phase 3 execution tools.

## Key Files

### Created
- `vmcluster_mcp/exec/ssh.py` — `SSHConnectionManager` class with caching, reconnect, and structured output
- `tests/test_ssh_client.py` — 9 unit tests covering all behaviour paths

## Decisions Made

- Cache key is `(ip, port, user, key_path)` tuple — covers multiple users/keys per host
- `asyncssh.TimeoutError` caught before `OSError` handler (it IS-A OSError); returns `timed_out=True`
- Stale connection (ConnectionLost, DisconnectError, OSError) → invalidate + retry once; second failure → `ExecResult(exit_code=-1, timed_out=False, stderr=str(exc))`
- `known_hosts=None` used for internal cluster trust (all hosts are trusted)
- `time.monotonic()` for duration measurement

## Verification

- `pytest tests/test_ssh_client.py -x` — 9/9 passed
- `ruff check vmcluster_mcp/exec/ssh.py` — no errors

## Self-Check: PASSED
