postgresql & migrations

internal/repository/postgresql/postgresql.go

@@ -0,0 +1,76 @@
+package postgresql
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"log/slog"
+
+	"gitea.computernetthings.ru/yash/crypto_alert_bot/internal/config"
+	"gitea.computernetthings.ru/yash/crypto_alert_bot/internal/repository/postgresql/migrations"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+
+	"github.com/golang-migrate/migrate/v4"
+	pgx "github.com/golang-migrate/migrate/v4/database/pgx/v5"
+	"github.com/golang-migrate/migrate/v4/source/iofs"
+	_ "github.com/jackc/pgx/v5/stdlib"
+)
+
+type Postgresql struct {
+	db *pgxpool.Pool
+}
+
+func New(ctx context.Context, log *slog.Logger, cfg *config.Postgresql) (*Postgresql, error) {
+	pool, err := pgxpool.New(ctx, fmt.Sprintf("postgres://%s:%s@%s/%s?sslmode=disable", cfg.User, cfg.Password, cfg.Address, cfg.DBName))
+	if err != nil {
+		return nil, fmt.Errorf("failed to connect to postgres: %w", err)
+	}
+
+	if err = pool.Ping(ctx); err != nil {
+		return nil, err
+	}
+
+	// apply migrations automatically
+	if err = applyMigrations(cfg, log); err != nil {
+		return nil, fmt.Errorf("failed to apply migrations: %w", err)
+	}
+
+	return &Postgresql{db: pool}, nil
+}
+
+func applyMigrations(cfg *config.Postgresql, log *slog.Logger) error {
+	dsn := fmt.Sprintf("postgres://%s:%s@%s/%s?sslmode=disable", cfg.User, cfg.Password, cfg.Address, cfg.DBName)
+
+	sqlDB, err := sql.Open("pgx", dsn)
+	if err != nil {
+		return fmt.Errorf("failed to open sql db for migrations: %w", err)
+	}
+	defer sqlDB.Close()
+
+	driver, err := pgx.WithInstance(sqlDB, &pgx.Config{})
+	if err != nil {
+		return fmt.Errorf("failed to create pgx driver: %w", err)
+	}
+
+	d, err := iofs.New(migrations.Folder, ".")
+	if err != nil {
+		return fmt.Errorf("failed to create iofs source: %w", err)
+	}
+
+	m, err := migrate.NewWithInstance("iofs", d, "postgres", driver)
+	if err != nil {
+		return fmt.Errorf("failed to create postgresql db migration: %w", err)
+	}
+
+	if err := m.Up(); err != nil {
+		if errors.Is(err, migrate.ErrNoChange) {
+			log.Info("no migrations to process")
+			return nil
+		}
+		return err
+	}
+	log.Info("migrations processed")
+	return nil
+}