Add PostgreSQL, user/squad management, remove private domains from docs

internal/db/db.go

@@ -0,0 +1,65 @@
+package db
+
+import (
+	"context"
+	"embed"
+	"fmt"
+	"time"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+//go:embed migrations/*.sql
+var migrationsFS embed.FS
+
+type DB struct {
+	pool *pgxpool.Pool
+}
+
+func Connect(ctx context.Context, databaseURL string) (*DB, error) {
+	cfg, err := pgxpool.ParseConfig(databaseURL)
+	if err != nil {
+		return nil, fmt.Errorf("parse database url: %w", err)
+	}
+	cfg.MaxConns = 10
+	cfg.MinConns = 1
+
+	pool, err := pgxpool.NewWithConfig(ctx, cfg)
+	if err != nil {
+		return nil, fmt.Errorf("connect postgres: %w", err)
+	}
+
+	ctx, cancel := context.WithTimeout(ctx, 10*time.Second)
+	defer cancel()
+	if err := pool.Ping(ctx); err != nil {
+		pool.Close()
+		return nil, fmt.Errorf("ping postgres: %w", err)
+	}
+
+	d := &DB{pool: pool}
+	if err := d.migrate(ctx); err != nil {
+		pool.Close()
+		return nil, err
+	}
+	return d, nil
+}
+
+func (d *DB) Close() {
+	d.pool.Close()
+}
+
+func (d *DB) migrate(ctx context.Context) error {
+	data, err := migrationsFS.ReadFile("migrations/001_init.sql")
+	if err != nil {
+		return fmt.Errorf("read migration: %w", err)
+	}
+	_, err = d.pool.Exec(ctx, string(data))
+	if err != nil {
+		return fmt.Errorf("apply migration: %w", err)
+	}
+	return nil
+}
+
+func (d *DB) Pool() *pgxpool.Pool {
+	return d.pool
+}