---
agent: host-operator
engagement_id: eng-coulomb-railiance01-ho-001
project: coulomb-railiance01
last_updated: '2026-07-22'
session_count: 7
confidentiality: client_owned
---

# Host Operator Memory — railiance01 pilot

## Engagement Charter

- **Duty:** Keep railiance01 operational and secure; OS currency; load and workload review
- **Cadence:** daily health/load (business days); weekly OS/security pass
- **Change windows:** prefer low-traffic periods; reboot only with human approval
- **Escalation:** coulomb / railiance human operator (Bernd / on-call as designated)
- **Out of scope:** app features; other hosts; secret vending
- **Access:** `ssh railiance01` as tegwick (host_observe verified 2026-07-16)

## Project Context

Coulomb ecosystem production host `railiance01` runs k3s and platform workloads
(including Forgejo/apps per railiance-hosts docs). This engagement is the first
forward-deployed host-operator pilot (KAIZEN-WP-0009).

## Host Profiles

| hostname | role | typical load | services | last review |
|----------|------|--------------|----------|-------------|
| railiance01 | k3s production single-node | calmer after reboot (~load 2 on 2 cores) | k3s, gitea, temporal, activity-core, state-hub | 2026-07-16 capacity check |


## OS & Patch State

- Ubuntu 24.04 LTS (noble); kernel 6.8.0-87-generic (needrestart KSTA=1 — no reboot required after 2026-07-16 upgrade)
- **2026-07-16:** full `apt-get upgrade` applied (approved); certs/ca updated; some service restarts deferred
- unattended-upgrades / logind may still want restart; re-login SSH sessions recommended


## Security Posture

- UFW active: OpenSSH Anywhere; **6443 only from operator IPs** 89.244.90.246 and 85.132.220.102
- **8472/udp world-open removed** (single-node; re-add if multi-node flannel peers needed)
- UFW backup: /etc/ufw/user.rules.bak.20260716
- 2026-07-16 package upgrades applied (security-relevant packages included)


## Load & Workload Envelope

| Field | 2026-07-16 capacity check (post operator upgrade claim) |
|-------|--------------------------------------------------------|
| Cores (guest) | **still 2** — operator reported 4; not visible yet |
| RAM (guest) | **still ~3.8 GiB** — operator reported 16 GiB; not visible yet |
| Load 1m | ~2 (improved vs Critical era) |
| MemAvailable | ~0.9 GiB |
| Swap | 4 GiB file, ~300 Mi used |
| PSI memory full avg60 | ~0.2% |
| k3s | Ready |

Do **not** treat 4/16 as baseline until `nproc` and `free -h` match.
See reports/2026-07-16-capacity-upgrade-check.md


## Accumulated Findings

- Undersized RAM for workload density is the dominant risk
- k3s API instability under memory pressure
- Large journald footprint
- Pending OS security updates

## What Worked

- Observe path via `ssh railiance01` (tegwick + id_custodian_agent)
- passwordless `sudo -n` for read-only needrestart/ufw/k3s inspect
- Engagement vault + close-session for durable evidence

## Watch Points

- Single-node production: privileged mistakes have full blast radius
- DinD / Actions runner privilege model (railiance-hosts ADR-004)
- Disk growth from images, logs, and backups
- Do not schedule heavy CI/agents until memory recovers
- Bridge reverse-forward port collisions (18765)

## Recurring Findings

- Memory pressure on 3.8G host · first seen 2026-07-16 · mitigated by swap but capacity still tight
- Load ≫ cores · improved after remediation; still watch


## Cleared Issues

- No swap · cleared 2026-07-16 via /swapfile 4G + fstab
- journald 4G bloat · vacuumed to ~500M target 2026-07-16
- World-open k3s API 6443 · restricted to operator IPs 2026-07-16
- World-open flannel 8472 · removed 2026-07-16 (single-node)
- Pending package upgrades · apt upgrade applied 2026-07-16


## Open Threads

- **Confirm VM resize:** operator reported 4 vCPU / 16 GiB; live guest still 2 / 3.8 GiB (2026-07-16 check)
- After 4/16 confirmed: update baseline; consider whether to keep full 4G swap or shrink
- Re-login stale SSH sessions after earlier apt upgrade if not done
- UFW: add new admin public IPs when they change (see access-plan allowlist procedure)


## Session Log

- 2026-07-16 · railiance01 · standard_review · T09 wire-up smoke: prepare+close-session path verified (no host access) · ok
- 2026-07-16 · railiance01 · first live observe: Critical memory/load; k3s API unavailable; RU checklist complete · ok
- 2026-07-16 · railiance01 · deep_assessment · T10 ramp-up complete: Critical memory/load, k3s API unavailable, RU all done, phase operating · ok
- 2026-07-16 · railiance01 · privileged remediation P1–P4 applied (swap, journal, apt, ufw) · ok
- 2026-07-16 · railiance01 · deep_assessment · Approved P1-P4 done: 4G swap, journal vacuum, apt upgrade, UFW k3s API allowlist; k3s Ready; RAM still tight · ok
- 2026-07-16 · railiance01 · capacity check after operator 4CPU/16G report: guest still 2/3.8G · watch
- 2026-07-16 · railiance01 · standard_review · Operator reported 4CPU/16G upgrade; live guest still 2CPU/3.8G after reboot; k3s Ready; load calmer · ok
- 2026-07-21 · railiance01 · capacity recheck: guest still 2CPU/3.8G (not 4/16); swap 1.1G used · watch
- 2026-07-21 · railiance01 · short_assist · Capacity recheck 2026-07-21: guest still 2CPU/3.8G not 4/16; k3s Ready; swap 1.1G used · ok
- 2026-07-22 · railiance01 · short_assist · Reboot completed; guest still 2CPU/3.8G not 4/16; resize must be finished in provider panel · ok