---
phase: 02-docker-integration
plan: 02
subsystem: api
tags: [n8n, docker-api, telegram, fuzzy-matching, workflow]

requires:
  - phase: 02-docker-integration/01
    provides: Docker socket access from n8n container
  - phase: 01-foundation
    provides: Telegram trigger and authentication workflow

provides:
  - Docker container status queries via Telegram
  - Fuzzy container name matching
  - Summary and detailed container views

affects: [03-container-actions, 04-logs-intelligence]

tech-stack:
  added: []
  patterns: [execute-command-curl, switch-routing, fuzzy-match]

key-files:
  created: []
  modified: [n8n-workflow.json]

key-decisions:
  - "Use curl -s flag to suppress stderr progress output"
  - "Only validate stdout JSON, ignore stderr for error detection"
  - "Simple substring matching for container names (no external library)"

patterns-established:
  - "Execute Command node with curl for Docker API queries"
  - "Code nodes for JSON parsing and response formatting"
  - "Switch node for message routing based on content"

duration: ~30min
completed: 2026-01-29
---

# Phase 2 Plan 02: Docker Query Workflow Summary

**n8n workflow extended with Docker query capability - status summaries and container details via Telegram**

## Performance

- **Duration:** ~30 min
- **Started:** 2026-01-29T14:35:00Z
- **Completed:** 2026-01-29T15:05:00Z
- **Tasks:** 3
- **Files modified:** 1

## Accomplishments

- Added Switch node to route "status" messages to Docker query branch
- Execute Command node queries Docker API via Unix socket with curl
- Code nodes parse JSON, implement fuzzy container name matching, and format responses
- Emoji status indicators (✅ running, ❌ stopped, etc.)
- Summary view shows container counts by state
- Detail view shows name, state, status, image, and ID
- Echo branch preserved for non-docker messages

## Task Commits

1. **Task 1: Add Docker Query Branch to Workflow** - `1252ff4` (feat)
2. **Bug fix: False positive docker error** - `8e155c5` (fix)

**Plan metadata:** (this commit)

## Files Created/Modified

- `n8n-workflow.json` - Extended with Docker query branch (5 new nodes)

## Decisions Made

| Decision | Rationale |
|----------|-----------|
| Use curl -s (silent) flag | Suppresses progress output to stderr that caused false error detection |
| Validate only stdout for errors | stderr contains curl progress info even on success |
| Simple substring matching | No external library needed, works well for container names |
| Strip linuxserver-/binhex- prefixes | Common Unraid container naming patterns |

## Deviations from Plan

### Bug Fix: stderr False Positive

- **Found during:** Task 3 (verification)
- **Issue:** curl writes progress to stderr even on success, triggering error handler
- **Fix:** Added -s flag to curl, changed error check to only validate stdout JSON
- **Committed in:** 8e155c5

---

**Total deviations:** 1 bug fix during verification
**Impact on plan:** Minor fix, no scope change

## Issues Encountered

- Initial error handling checked for any stderr content, but curl writes progress info there even on success. Fixed by using -s flag and only checking stdout validity.

## User Setup Required

None - workflow file updated, user imports into n8n.

## Next Phase Readiness

- Docker query capability complete and verified
- Foundation ready for Phase 3: Container Actions (start/stop/restart)
- Fuzzy matching pattern established for reuse in action commands

---
*Phase: 02-docker-integration*
*Completed: 2026-01-29*