refactor: extract connection to database logic to db module

cmd/main.go

@@ -7,31 +7,22 @@ import (
 	"os"
 
 	"git.ksdemosapps.com/kylesoda/pgx-learning/internal/config"
+	"git.ksdemosapps.com/kylesoda/pgx-learning/internal/db"
 	"git.ksdemosapps.com/kylesoda/pgx-learning/internal/db/postgres"
 	"git.ksdemosapps.com/kylesoda/pgx-learning/internal/models"
 	"git.ksdemosapps.com/kylesoda/pgx-learning/internal/repository"
-	"github.com/jackc/pgx/v5/pgxpool"
 	"github.com/urfave/cli/v2"
 )
 
-var pool *pgxpool.Pool
-var ctx = context.Background()
-
-func init() {
-	var err error
-	pool, err = pgxpool.New(ctx, config.Db.Url)
-	if err != nil {
-		log.Fatal("Unable to connect to database:", err)
-	}
-
-	if err := pool.Ping(ctx); err != nil {
-		log.Fatal("Unable to ping database:", err)
-	}
-
-	// fmt.Println("Connected to PostgreSQL database!")
-}
-
 func main() {
+	ctx := context.Background()
+
+	pool, err := db.Connect(ctx, config.Db.Url)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer db.Close(pool)
+
 	taskRespository := postgres.NewTaskRepository(pool)
 
 	app := &cli.App{
@@ -175,7 +166,7 @@ func main() {
 		},
 	}
 
-	err := app.Run(os.Args)
+	err = app.Run(os.Args)
 	if err != nil {
 		log.Fatal(err)
 	}

internal/db/connection.go

@@ -0,0 +1,28 @@
+package db
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+func Connect(ctx context.Context, dbURL string) (*pgxpool.Pool, error) {
+	pool, err := pgxpool.New(ctx, dbURL)
+	if err != nil {
+		return nil, fmt.Errorf("unable to connect to database: %w", err)
+	}
+
+	if err := pool.Ping(ctx); err != nil {
+		pool.Close()
+		return nil, fmt.Errorf("unable to ping database: %w", err)
+	}
+
+	return pool, nil
+}
+
+func Close(pool *pgxpool.Pool) {
+	if pool != nil {
+		pool.Close()
+	}
+}