mirror-nourybot/cmd/api/main.go

package main

import (
	"context"
	"database/sql"
	"fmt"
	"log"
	"net/http"
	"os"
	"time"

	"github.com/joho/godotenv"
	_ "github.com/lib/pq"
	"github.com/lyx0/nourybot/internal/data"
	"go.uber.org/zap"
)

type config struct {
	port int
	db   struct {
		dsn          string
		maxOpenConns int
		maxIdleConns int
		maxIdleTime  string
	}
}

type application struct {
	Logger *zap.SugaredLogger
	Db     *sql.DB
	Models data.Models
}

func main() {
	var cfg config

	// Initialize a new sugared logger that we'll pass on
	// down through the application.
	sugar := zap.NewExample().Sugar()
	defer sugar.Sync()

	err := godotenv.Load()
	if err != nil {
		log.Fatal("Error loading .env file")
	}

	// Database
	cfg.db.dsn = os.Getenv("DB_DSN")
	cfg.port = 3000
	cfg.db.maxOpenConns = 25
	cfg.db.maxIdleConns = 25
	cfg.db.maxIdleTime = "15m"

	// Establish database connection
	db, err := openDB(cfg)
	if err != nil {
		sugar.Fatal(err)
	}

	// Initialize Application
	app := &application{
		Logger: sugar,
		Db:     db,
		Models: data.NewModels(db),
	}

	srv := &http.Server{
		Addr:         fmt.Sprintf(":%d", cfg.port),
		Handler:      app.routes(),
		IdleTimeout:  time.Minute,
		ReadTimeout:  10 * time.Second,
		WriteTimeout: 10 * time.Second,
	}

	err = srv.ListenAndServe()
	sugar.Fatal(err)
}

// openDB returns the sql.DB connection pool.
func openDB(cfg config) (*sql.DB, error) {
	// sql.Open() creates an empty connection pool with the provided DSN
	db, err := sql.Open("postgres", cfg.db.dsn)
	if err != nil {
		return nil, err
	}

	// Set database restraints.
	db.SetMaxOpenConns(cfg.db.maxOpenConns)
	db.SetMaxIdleConns(cfg.db.maxIdleConns)

	// Parse the maxIdleTime string into an actual duration and set it.
	duration, err := time.ParseDuration(cfg.db.maxIdleTime)
	if err != nil {
		return nil, err
	}
	db.SetConnMaxIdleTime(duration)

	// Create a new context with a 5 second timeout.
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	// db.PingContext() is needed to actually check if the
	// connection to the database was successful.
	err = db.PingContext(ctx)
	if err != nil {
		return nil, err
	}

	return db, nil
}