refactor:

pkg/external/aws/aws.go

@@ -0,0 +1 @@
+package aws

pkg/external/kafka/kafka.go

@@ -0,0 +1 @@
+package kafka

pkg/external/ms-auth/client.go

@@ -0,0 +1 @@
+package ms_auth

pkg/external/pandoc/pandoc.go

@@ -0,0 +1,71 @@
+package pandoc
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+)
+
+type Client struct {
+	client  *http.Client
+	address string
+}
+
+type PandocClient interface {
+	ConvertLatexToHtml5(ctx context.Context, text string) (string, error)
+}
+
+func NewPandocClient(client *http.Client, address string) *Client {
+	return &Client{
+		client:  client,
+		address: address,
+	}
+}
+
+type convertRequest struct {
+	Text string `json:"text"`
+	From string `json:"from"`
+	To   string `json:"to"`
+}
+
+func (client *Client) convert(ctx context.Context, text, from, to string) (string, error) {
+	body, err := json.Marshal(convertRequest{
+		Text: text,
+		From: from,
+		To:   to,
+	})
+	if err != nil {
+		return "", err
+	}
+
+	buf := bytes.NewBuffer(body)
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, client.address, buf)
+	if err != nil {
+		return "", err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	resp, err := client.client.Do(req)
+	if err != nil {
+		return "", err
+	}
+
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return "", err
+	}
+
+	body, err = io.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+
+	return string(body), nil
+}
+
+func (client *Client) ConvertLatexToHtml5(ctx context.Context, text string) (string, error) {
+	return client.convert(ctx, text, "latex", "html5")
+}

pkg/external/postgres/postgres.go

@@ -0,0 +1,30 @@
+package postgres
+
+import (
+	"github.com/jmoiron/sqlx"
+	"time"
+)
+
+const (
+	maxOpenConns    = 60
+	connMaxLifetime = 120
+	maxIdleConns    = 30
+	connMaxIdleTime = 20
+)
+
+func NewPostgresDB(dsn string) (*sqlx.DB, error) {
+	db, err := sqlx.Open("pgx", dsn)
+	if err != nil {
+		return nil, err
+	}
+
+	db.SetMaxOpenConns(maxOpenConns)
+	db.SetConnMaxLifetime(connMaxLifetime * time.Second)
+	db.SetMaxIdleConns(maxIdleConns)
+	db.SetConnMaxIdleTime(connMaxIdleTime * time.Second)
+	if err = db.Ping(); err != nil {
+		return nil, err
+	}
+
+	return db, nil
+}

pkg/external/valkey/valkey.go

@@ -0,0 +1,12 @@
+package valkey
+
+import "github.com/valkey-io/valkey-go"
+
+func NewValkeyClient(dsn string) (valkey.Client, error) {
+	opts, err := valkey.ParseURL(dsn)
+	if err != nil {
+		return nil, err
+	}
+
+	return valkey.NewClient(opts)
+}