providers/ldap: memory Query (#1681)

* outposts/ldap: modularise ldap outpost, to allow different searchers and binders

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* outposts/ldap: add basic in-memory searcher

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* providers/ldap: add search mode field

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* outpost: add search mode field

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

internal/outpost/ldap/server/base.go

@@ -0,0 +1,35 @@
+package server
+
+import (
+	"github.com/go-openapi/strfmt"
+	"github.com/nmcclain/ldap"
+	"goauthentik.io/api"
+	"goauthentik.io/internal/outpost/ldap/flags"
+)
+
+type LDAPServerInstance interface {
+	GetAPIClient() *api.APIClient
+	GetOutpostName() string
+
+	GetFlowSlug() string
+	GetAppSlug() string
+	GetSearchAllowedGroups() []*strfmt.UUID
+
+	UserEntry(u api.User) *ldap.Entry
+
+	GetBaseDN() string
+	GetBaseGroupDN() string
+	GetBaseUserDN() string
+
+	GetUserDN(string) string
+	GetGroupDN(string) string
+	GetVirtualGroupDN(string) string
+
+	GetUidNumber(api.User) string
+	GetGidNumber(api.Group) string
+
+	UsersForGroup(api.Group) []string
+
+	GetFlags(string) (flags.UserFlags, bool)
+	SetFlags(string, flags.UserFlags)
+}