Add configuration files, database migrations, and authentication implementation scaffolding

internal/db/db.go

@@ -0,0 +1,51 @@
+package db
+
+import (
+	"database/sql"
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/golang-migrate/migrate/v4"
+	_ "github.com/golang-migrate/migrate/v4/database/postgres"
+	_ "github.com/golang-migrate/migrate/v4/source/file"
+	_ "github.com/lib/pq"
+)
+
+// Connect initializes a standard sql.DB connection with retries.
+func Connect(dsn string) (*sql.DB, error) {
+	var db *sql.DB
+	var err error
+
+	for i := 0; i < 10; i++ {
+		db, err = sql.Open("postgres", dsn)
+		if err == nil {
+			err = db.Ping()
+			if err == nil {
+				return db, nil
+			}
+		}
+		fmt.Printf("Failed to connect to database, retrying in 2s... (%d/10)\n", i+1)
+		time.Sleep(2 * time.Second)
+	}
+
+	return nil, fmt.Errorf("failed to connect to database after retries: %w", err)
+}
+
+// RunMigrations runs the SQL migrations from internal/db/migrations.
+func RunMigrations(dsn string) error {
+	m, err := migrate.New(
+		"file://internal/db/migrations",
+		dsn,
+	)
+	if err != nil {
+		return fmt.Errorf("could not create migrate instance: %w", err)
+	}
+
+	if err := m.Up(); err != nil && err != migrate.ErrNoChange {
+		return fmt.Errorf("could not run up migrations: %w", err)
+	}
+
+	log.Println("Migrations completed successfully")
+	return nil
+}