PinLog

An AI place journal that finds places again by experience and feeling, even when you forget the name

Screens

Overview

Period: Jul – Aug 2026 (5 weeks)
Team: 6 people · SSAFY team project
Role: Infra lead

The problem

Saved places are hard to find again once you forget the name, and why you saved them is lost. On the infra side, several services had to be deployed and run on a single given server without cloud API access.

The approach

01
Natural-language search over your own contextPlaces are saved with the reason and experience behind them, and found again by a sentence instead of a name.
02
Discovery through anonymous collectionsPublic collections that hide identity and original notes let you discover others' taste, then add your own context to what you find.
03
GitOps on a single serverEvery service ships through a shared Helm chart, and Argo CD applies the state declared in Git to k3s.

My work

Led the design and build of the k3s deployment and operations platform: deploy automation, resource isolation, observability, AI-assisted alerts, and backup and recovery.

01
Only verified images shipDeploy PRs are opened only after CI success and the registry digest are verified, the commit is rechecked before merge, and rollbacks are recorded as Git reverts.GitHub Actions · private GHCR · pinned full commit SHA + image digest · Helm · Argo CD ApplicationSet
02
Splitting one server's resourcesSeparate dev and prod areas, resource ceilings and capped observability storage keep services from starving each other.Namespaces · resource budgets · NetworkPolicy · Pod Security Admission
03
AI-assisted alertsAlerts are summarized in Korean from a limited set of related metrics and logs. If the AI fails or evidence is thin, a rule-based alert goes out instead, and nothing in the cluster is changed automatically.Alertmanager → Sentinel Receiver (redaction · allow-listed JSON) → AI API → output validation → Mattermost
04
Observability and external probesMetrics, logs and dashboards, plus a separate external HTTPS/TLS probe so a full server outage is still reported.Prometheus · Loki · Alloy · Grafana · GitHub-hosted external probe
05
Secrets and accessSecrets are encrypted in Git, and deploy automation tokens are scoped per repository with least privilege.Sealed Secrets · least-privilege tokens · Cloudflare Tunnel · Traefik

Fixed in production

01
Container runtime eating CPUKubelet polling through Docker and cri-dockerd kept the CPU busy; switching to K3s embedded containerd removed that layer, using a procedure with DB backup, preserved config and a rollback path.
02
A broken backup could become the latest restore pointDumps are now checked as archives, and only verified files are atomically promoted to latest.dump.

Stack

Infra: k3s · Helm · Argo CD · GitHub Actions · Cloudflare · Traefik
Observability: Prometheus · Loki · Alloy · Grafana · Alertmanager
Backend: Spring Boot · PostgreSQL + pgvector · Redis
AI: FastAPI · pgvector
Frontend: React 19 · TypeScript · Vite · TanStack Router/Query

Engineering · July 29, 2026

Runtime Contracts and Infrastructure Ownership Boundaries for Deployment

Runtime contracts, infrastructure ownership, and the gap between passing checks and deploying: a look back at PinLog’s July 2026 records.

Retrospective · July 29, 2026

Agreeing on How We Develop Before Bringing AI Agents into the Team

Applying AlgoSu’s AI agent practices to PinLog started with aligning people: making assumptions explicit and agreeing on structure, conventions, and ownership.

Engineering · July 22, 2026

PVC Retention Policies and Data Recovery Limits on Single-Node k3s

Looking at local-path and local-path-retain on a single-node k3s cluster, I separated three questions: Pod restarts, PVC deletion, and recovery after losing the node.

AI Agents · July 22, 2026

Separating an Operations AI’s Memory from Actual Server State

Separating observations, contracts, evidence, and query views when using Pico’s memory for operational decisions.

AI Agents · July 21, 2026

AI Processing of Incident Alerts, with Output Verified by Code

PinLog's Sentinel uses Hermes to process alert payloads, while trusted code revalidates mentions, URLs, and the final format. Critical, Warning, and RESOLVED policies, plus a closing one-line summary, make that division of responsibility concrete.

Engineering · July 21, 2026

An External Monitoring Path That Works Even When the Node Fails

Internal alerts cannot watch over the complete failure of the node they run on. How PinLog separates internal monitoring from external HTTPS/TLS checks, and what that separation does not solve.