homelabby/.planning/phases/06-lab-advisor/06-01-SUMMARY.md

phase	plan	subsystem	tags	dependency_graph	tech_stack	key_files	decisions	metrics
06-lab-advisor	01	store	postgresql pgx persistence store migrations	requires provides affects internal/store 06-02 06-03	added patterns github.com/jackc/pgx/v5 v5.9.1 github.com/jackc/puddle/v2 v2.2.2 github.com/jackc/pgpassfile v1.0.0 github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 pgxpool for connection pooling (not single conn) Parameterized $N queries throughout (no string interpolation) ErrNotFound sentinel for missing resources Integration tests gated behind `//go:build integration` tag	created modified internal/store/store.go internal/store/migrations.go internal/store/conversations.go internal/store/store_test.go go.mod go.sum	Used dot-import in external test package to avoid verbose `store.NewStore` prefix while keeping package boundary clean Used LEFT JOIN in GetConversation to handle conversations with zero messages, scanning nullable message columns Added LIMIT 100 to ListConversations per T-06-01-04 (DoS guard for unbounded growth) DSN never logged on connection error — only error text forwarded (T-06-01-02)	duration_seconds completed_at tasks_completed tasks_total files_created files_modified 124 2026-04-10T07:31:15Z 2 2 4 2

Phase 06 Plan 01: PostgreSQL Store Package Summary

One-liner: pgx/v5 connection pool with idempotent schema migrations and typed CRUD for conversations + messages, backed by live PostgreSQL at 10.5.0.109.

Tasks Completed

#	Name	Commit	Files
1	Add pgx/v5 dep and create Store with RunMigrations	4bc22dc	store.go, migrations.go, go.mod, go.sum
2	Conversation and message CRUD methods	623cff0	conversations.go, store_test.go

What Was Built

internal/store/store.go

Store struct wrapping *pgxpool.Pool. NewStore(ctx, dsn) opens the pool and pings before returning. Close() drains the pool. Pool() accessor gives migrations and tests direct pool access.

internal/store/migrations.go

RunMigrations(ctx, pool) executes two CREATE TABLE IF NOT EXISTS statements in dependency order (conversations first, then messages which references it via FK). Safe to call on every startup.

Schema:

• conversations(id UUID PK DEFAULT gen_random_uuid(), started_at TIMESTAMPTZ DEFAULT now(), model TEXT DEFAULT '')
• messages(id UUID PK, conversation_id UUID FK REFERENCES conversations ON DELETE CASCADE, role TEXT CHECK IN ('user','assistant','system'), content TEXT, created_at TIMESTAMPTZ DEFAULT now())

internal/store/conversations.go

Types: Message, Conversation, ConversationSummary, ErrNotFound.

Methods on *Store:

• CreateConversation(ctx, model) (id string, err error)
• AddMessage(ctx, conversationID, role, content) (id string, err error) — DB CHECK constraint rejects invalid roles
• GetConversation(ctx, id) (*Conversation, error) — LEFT JOIN to handle zero-message conversations; returns ErrNotFound on miss
• ListConversations(ctx) ([]ConversationSummary, error) — COUNT(m.id) aggregation with LIMIT 100 soft guard

internal/store/store_test.go

Integration tests (build tag: integration) covering all behaviors from the plan spec. Each sub-test creates its own fixtures and cleans up via deferred DELETE. Tests connect to the real PostgreSQL instance.

Deviations from Plan

None — plan executed exactly as written. The dot-import (import . "git.georgsen.dk/hwlab/internal/store") in the test file is a minor stylistic choice for readability in external test packages, consistent with common Go testing practice for the same package's integration tests.

Threat Mitigations Applied

Threat ID	Mitigation
T-06-01-01	All queries use $1/$2 parameterized args via pgx; zero string interpolation in SQL
T-06-01-02	NewStore wraps error without including DSN; only pgx error text is forwarded
T-06-01-03	DB-level CHECK (role IN ('user','assistant','system')) — verified by test
T-06-01-04	LIMIT 100 added to ListConversations

Known Stubs

None — all methods are fully wired to the live database.

Self-Check: PASSED

• internal/store/store.go: exists
• internal/store/migrations.go: exists
• internal/store/conversations.go: exists
• internal/store/store_test.go: exists
• Commit 4bc22dc: verified in git log
• Commit 623cff0: verified in git log
• go build ./...: PASSED
• Integration tests: 12/12 PASSED