feat: added migrations

cmd/migrate/main.go

@@ -0,0 +1,78 @@
+package main
+
+import (
+	"database/sql"
+	"embed"
+	"errors"
+	"flag"
+	"log"
+
+	"orderservice/internal/config"
+
+	"github.com/golang-migrate/migrate/v4"
+	"github.com/golang-migrate/migrate/v4/database/postgres"
+	"github.com/golang-migrate/migrate/v4/source/iofs"
+)
+
+//go:embed migrations/*.sql
+var migrationsFS embed.FS
+
+func main() {
+	var cmd string
+
+	flag.StringVar(&cmd, "cmd", "up", "migration command: up|down|force|version")
+	flag.Parse()
+
+	cfg, err := config.Load()
+	if err != nil {
+		log.Fatalf("failed to load config: %v", err)
+	}
+
+	db, err := sql.Open("postgres", cfg.BuildPostgresDSN())
+	if err != nil {
+		log.Fatalf("open db: %v", err)
+	}
+	defer db.Close()
+
+	drv, err := postgres.WithInstance(db, &postgres.Config{})
+	if err != nil {
+		log.Printf("postgres driver: %v", err)
+		return
+	}
+
+	src, err := iofs.New(migrationsFS, "migrations")
+	if err != nil {
+		log.Printf("iofs source: %v", err)
+		return
+	}
+
+	m, err := migrate.NewWithInstance("iofs", src, "postgres", drv)
+	if err != nil {
+		log.Printf("migrate NewWithInstance: %v", err)
+		return
+	}
+
+	switch cmd {
+	case "up":
+		if err := m.Up(); err != nil && !errors.Is(err, migrate.ErrNoChange) {
+			log.Printf("m.Up failed: %v", err)
+			return
+		}
+		log.Println("migrations applied (up)")
+	case "down":
+		if err := m.Steps(-1); err != nil {
+			log.Printf("m.Steps(-1) failed: %v", err)
+			return
+		}
+		log.Println("stepped down 1 migration")
+	case "version":
+		v, dirty, verr := m.Version()
+		if verr != nil {
+			log.Printf("version: %v", verr)
+			return
+		}
+		log.Printf("version: %d dirty: %v\n", v, dirty)
+	default:
+		log.Printf("unknown cmd: %s", cmd)
+	}
+}

cmd/migrate/migrations/000001_create_orders_table.down.sql

@@ -0,0 +1 @@
+drop table if exists orders;

cmd/migrate/migrations/000001_create_orders_table.up.sql

@@ -0,0 +1,5 @@
+create table if not exists orders (
+    id uuid primary key,
+    item varchar(500) not null,
+    quantity integer not null check (quantity > 0)
+);