Database support

Added connection
Added healthcheck
Added migration

backend/db/db.go

@@ -0,0 +1,59 @@
+package db
+
+import (
+	"context"
+	"embed"
+	"log"
+	"time"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+var Pool *pgxpool.Pool
+
+func Connect(url string) error {
+	// Create context timeout, if connection takes more than 5 seconds, it will be canceled automatically
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	// Always cancel timeout to clean up resources
+	defer cancel()
+
+	// Open new connection with database url
+	var err error
+	Pool, err = pgxpool.New(ctx, url)
+	if err != nil {
+		log.Printf("[ERROR] Failed to connect to DB: %v\n", err)
+		return err
+	}
+
+	// Ping database to check if its online
+	err = Pool.Ping(ctx)
+	if err != nil {
+		log.Printf("[ERROR] Failed to ping DB: %v", err)
+		return err
+	}
+
+	// Connection successful
+	log.Printf("[INFO] Connected to DB: %v\n", url)
+	return nil
+}
+
+//go:embed migrations.sql
+var migrationFS embed.FS
+
+func Migrate() error {
+	// Read file from embed
+	sql, err := migrationFS.ReadFile("migrations.sql")
+	if err != nil {
+		log.Printf("[ERROR] Failed to read migrations.sql: %v\n", err)
+		return err
+	}
+
+	// Execute sql file into database
+	_, err = Pool.Exec(context.Background(), string(sql))
+	if err != nil {
+		log.Printf("[ERROR] Failed to migrate DB: %v\n", err)
+		return err
+	}
+
+	return nil
+}