Added simple database connection

internal/database/db.go

@@ -0,0 +1,29 @@
+package database
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"time"
+
+	_ "github.com/jackc/pgx/v5/stdlib"
+)
+
+func New(ctx context.Context, connURL string) (*sql.DB, error) {
+	db, err := sql.Open("pgx", connURL)
+	if err != nil {
+		return nil, fmt.Errorf("failed to connect to database: %w", err)
+	}
+
+	db.SetMaxOpenConns(10)
+	db.SetMaxIdleConns(10)
+
+	db.SetConnMaxLifetime(5 * time.Minute)
+	db.SetConnMaxIdleTime(5 * time.Minute)
+
+	if err := db.PingContext(ctx); err != nil {
+		return nil, fmt.Errorf("database unreachable: %w", err)
+	}
+
+	return db, nil
+}