refactor: rework file structure (#325)

* wip: add middlewares

* refactor: use context fom middleware in handlers

* refactor: use controller approach in handlers

* refactor: move oauth providers into services (non-working)

* feat: create oauth broker service

* refactor: use a boostrap service to bootstrap the app

* refactor: split utils into smaller files

* refactor: use more clear name for frontend assets

* feat: allow customizability of resources dir

* fix: fix typo in ui middleware

* fix: validate resource file paths in ui middleware

* refactor: move resource handling to a controller

* feat: add some logging

* fix: configure middlewares before groups

* fix: use correct api path in login mutation

* fix: coderabbit suggestions

* fix: further coderabbit suggestions

internal/service/ldap_service.go

@@ -0,0 +1,155 @@
+package service
+
+import (
+	"context"
+	"crypto/tls"
+	"fmt"
+	"time"
+
+	"github.com/cenkalti/backoff/v5"
+	ldapgo "github.com/go-ldap/ldap/v3"
+	"github.com/rs/zerolog/log"
+)
+
+type LdapServiceConfig struct {
+	Address      string
+	BindDN       string
+	BindPassword string
+	BaseDN       string
+	Insecure     bool
+	SearchFilter string
+}
+
+type LdapService struct {
+	Config LdapServiceConfig
+	Conn   *ldapgo.Conn
+}
+
+func NewLdapService(config LdapServiceConfig) *LdapService {
+	return &LdapService{
+		Config: config,
+	}
+}
+
+func (ldap *LdapService) Init() error {
+	_, err := ldap.connect()
+	if err != nil {
+		return fmt.Errorf("failed to connect to LDAP server: %w", err)
+	}
+
+	go func() {
+		for range time.Tick(time.Duration(5) * time.Minute) {
+			err := ldap.heartbeat()
+			if err != nil {
+				log.Error().Err(err).Msg("LDAP connection heartbeat failed")
+				if reconnectErr := ldap.reconnect(); reconnectErr != nil {
+					log.Error().Err(reconnectErr).Msg("Failed to reconnect to LDAP server")
+					continue
+				}
+				log.Info().Msg("Successfully reconnected to LDAP server")
+			}
+		}
+	}()
+
+	return nil
+}
+
+func (ldap *LdapService) connect() (*ldapgo.Conn, error) {
+	conn, err := ldapgo.DialURL(ldap.Config.Address, ldapgo.DialWithTLSConfig(&tls.Config{
+		InsecureSkipVerify: ldap.Config.Insecure,
+		MinVersion:         tls.VersionTLS12,
+	}))
+	if err != nil {
+		return nil, err
+	}
+
+	err = conn.Bind(ldap.Config.BindDN, ldap.Config.BindPassword)
+	if err != nil {
+		return nil, err
+	}
+
+	// Set and return the connection
+	ldap.Conn = conn
+	return conn, nil
+}
+
+func (ldap *LdapService) Search(username string) (string, error) {
+	// Escape the username to prevent LDAP injection
+	escapedUsername := ldapgo.EscapeFilter(username)
+	filter := fmt.Sprintf(ldap.Config.SearchFilter, escapedUsername)
+
+	searchRequest := ldapgo.NewSearchRequest(
+		ldap.Config.BaseDN,
+		ldapgo.ScopeWholeSubtree, ldapgo.NeverDerefAliases, 0, 0, false,
+		filter,
+		[]string{"dn"},
+		nil,
+	)
+
+	searchResult, err := ldap.Conn.Search(searchRequest)
+	if err != nil {
+		return "", err
+	}
+
+	if len(searchResult.Entries) != 1 {
+		return "", fmt.Errorf("multiple or no entries found for user %s", username)
+	}
+
+	userDN := searchResult.Entries[0].DN
+	return userDN, nil
+}
+
+func (ldap *LdapService) Bind(userDN string, password string) error {
+	err := ldap.Conn.Bind(userDN, password)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (ldap *LdapService) heartbeat() error {
+	log.Debug().Msg("Performing LDAP connection heartbeat")
+
+	searchRequest := ldapgo.NewSearchRequest(
+		"",
+		ldapgo.ScopeBaseObject, ldapgo.NeverDerefAliases, 0, 0, false,
+		"(objectClass=*)",
+		[]string{},
+		nil,
+	)
+
+	_, err := ldap.Conn.Search(searchRequest)
+	if err != nil {
+		return err
+	}
+
+	// No error means the connection is alive
+	return nil
+}
+
+func (ldap *LdapService) reconnect() error {
+	log.Info().Msg("Reconnecting to LDAP server")
+
+	exp := backoff.NewExponentialBackOff()
+	exp.InitialInterval = 500 * time.Millisecond
+	exp.RandomizationFactor = 0.1
+	exp.Multiplier = 1.5
+	exp.Reset()
+
+	operation := func() (*ldapgo.Conn, error) {
+		ldap.Conn.Close()
+		conn, err := ldap.connect()
+		if err != nil {
+			return nil, err
+		}
+		return conn, nil
+	}
+
+	_, err := backoff.Retry(context.TODO(), operation, backoff.WithBackOff(exp), backoff.WithMaxTries(3))
+
+	if err != nil {
+		return err
+	}
+
+	return nil
+}