Feature: LDAP refactoring (#16950)

* incapsulates multipleldap logic under one module

* abstracts users upsert and get logic

* changes some of the text error messages and import sort sequence

* heavily refactors the LDAP module – LDAP module now only deals with LDAP related behaviour

* integrates affected auth_proxy module and their tests

* refactoring of the auth_proxy logic

pkg/services/multildap/multildap.go

@@ -0,0 +1,204 @@
+package multildap
+
+import (
+	"errors"
+
+	"github.com/grafana/grafana/pkg/models"
+	"github.com/grafana/grafana/pkg/services/ldap"
+)
+
+// GetConfig gets LDAP config
+var GetConfig = ldap.GetConfig
+
+// IsEnabled checks if LDAP is enabled
+var IsEnabled = ldap.IsEnabled
+
+// ErrInvalidCredentials is returned if username and password do not match
+var ErrInvalidCredentials = ldap.ErrInvalidCredentials
+
+// ErrNoLDAPServers is returned when there is no LDAP servers specified
+var ErrNoLDAPServers = errors.New("No LDAP servers are configured")
+
+// ErrDidNotFindUser if request for user is unsuccessful
+var ErrDidNotFindUser = errors.New("Did not find a user")
+
+// IMultiLDAP is interface for MultiLDAP
+type IMultiLDAP interface {
+	Login(query *models.LoginUserQuery) (
+		*models.ExternalUserInfo, error,
+	)
+
+	Users(logins []string) (
+		[]*models.ExternalUserInfo, error,
+	)
+
+	User(login string) (
+		*models.ExternalUserInfo, error,
+	)
+
+	Add(dn string, values map[string][]string) error
+	Remove(dn string) error
+}
+
+// MultiLDAP is basic struct of LDAP authorization
+type MultiLDAP struct {
+	configs []*ldap.ServerConfig
+}
+
+// New creates the new LDAP auth
+func New(configs []*ldap.ServerConfig) IMultiLDAP {
+	return &MultiLDAP{
+		configs: configs,
+	}
+}
+
+// Add adds user to the *first* defined LDAP
+func (multiples *MultiLDAP) Add(
+	dn string,
+	values map[string][]string,
+) error {
+	if len(multiples.configs) == 0 {
+		return ErrNoLDAPServers
+	}
+
+	config := multiples.configs[0]
+	ldap := ldap.New(config)
+
+	if err := ldap.Dial(); err != nil {
+		return err
+	}
+
+	defer ldap.Close()
+
+	err := ldap.Add(dn, values)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Remove removes user from the *first* defined LDAP
+func (multiples *MultiLDAP) Remove(dn string) error {
+	if len(multiples.configs) == 0 {
+		return ErrNoLDAPServers
+	}
+
+	config := multiples.configs[0]
+	ldap := ldap.New(config)
+
+	if err := ldap.Dial(); err != nil {
+		return err
+	}
+
+	defer ldap.Close()
+
+	err := ldap.Remove(dn)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Login tries to log in the user in multiples LDAP
+func (multiples *MultiLDAP) Login(query *models.LoginUserQuery) (
+	*models.ExternalUserInfo, error,
+) {
+	if len(multiples.configs) == 0 {
+		return nil, ErrNoLDAPServers
+	}
+
+	for _, config := range multiples.configs {
+		server := ldap.New(config)
+
+		if err := server.Dial(); err != nil {
+			return nil, err
+		}
+
+		defer server.Close()
+
+		user, err := server.Login(query)
+
+		if user != nil {
+			return user, nil
+		}
+
+		// Continue if we couldn't find the user
+		if err == ErrInvalidCredentials {
+			continue
+		}
+
+		if err != nil {
+			return nil, err
+		}
+
+		return user, nil
+	}
+
+	// Return invalid credentials if we couldn't find the user anywhere
+	return nil, ErrInvalidCredentials
+}
+
+// User gets a user by login
+func (multiples *MultiLDAP) User(login string) (
+	*models.ExternalUserInfo,
+	error,
+) {
+
+	if len(multiples.configs) == 0 {
+		return nil, ErrNoLDAPServers
+	}
+
+	search := []string{login}
+	for _, config := range multiples.configs {
+		server := ldap.New(config)
+
+		if err := server.Dial(); err != nil {
+			return nil, err
+		}
+
+		defer server.Close()
+
+		users, err := server.Users(search)
+		if err != nil {
+			return nil, err
+		}
+
+		if len(users) != 0 {
+			return users[0], nil
+		}
+	}
+
+	return nil, ErrDidNotFindUser
+}
+
+// Users gets users from multiple LDAP servers
+func (multiples *MultiLDAP) Users(logins []string) (
+	[]*models.ExternalUserInfo,
+	error,
+) {
+	var result []*models.ExternalUserInfo
+
+	if len(multiples.configs) == 0 {
+		return nil, ErrNoLDAPServers
+	}
+
+	for _, config := range multiples.configs {
+		server := ldap.New(config)
+
+		if err := server.Dial(); err != nil {
+			return nil, err
+		}
+
+		defer server.Close()
+
+		users, err := server.Users(logins)
+		if err != nil {
+			return nil, err
+		}
+		result = append(result, users...)
+	}
+
+	return result, nil
+}