providers/ldap: correctly use pagination in search results in both modes (#5492)

closes #4292

Signed-off-by: Jens Langhammer <jens@goauthentik.io>

internal/outpost/ldap/utils/paginator/paginator.go

@@ -0,0 +1,64 @@
+package paginator
+
+import (
+	log "github.com/sirupsen/logrus"
+	"goauthentik.io/api/v3"
+)
+
+const PageSize = 100
+
+func FetchUsers(req api.ApiCoreUsersListRequest) []api.User {
+	fetchUsersOffset := func(page int) (*api.PaginatedUserList, error) {
+		users, _, err := req.Page(int32(page)).PageSize(PageSize).Execute()
+		if err != nil {
+			log.WithError(err).Warning("failed to update users")
+			return nil, err
+		}
+		log.WithField("page", page).WithField("count", len(users.Results)).Debug("fetched users")
+		return users, nil
+	}
+	page := 1
+	users := make([]api.User, 0)
+	for {
+		apiUsers, err := fetchUsersOffset(page)
+		if err != nil {
+			log.WithError(err).WithField("page", page).Warn("Failed to fetch user page")
+			continue
+		}
+		users = append(users, apiUsers.Results...)
+		if apiUsers.Pagination.Next > 0 {
+			page += 1
+		} else {
+			break
+		}
+	}
+	return users
+}
+
+func FetchGroups(req api.ApiCoreGroupsListRequest) []api.Group {
+	fetchGroupsOffset := func(page int) (*api.PaginatedGroupList, error) {
+		groups, _, err := req.Page(int32(page)).PageSize(PageSize).Execute()
+		if err != nil {
+			log.WithError(err).Warning("failed to update groups")
+			return nil, err
+		}
+		log.WithField("page", page).WithField("count", len(groups.Results)).Debug("fetched groups")
+		return groups, nil
+	}
+	page := 1
+	groups := make([]api.Group, 0)
+	for {
+		apiGroups, err := fetchGroupsOffset(page)
+		if err != nil {
+			log.WithError(err).WithField("page", page).Warn("Failed to fetch group page")
+			continue
+		}
+		groups = append(groups, apiGroups.Results...)
+		if apiGroups.Pagination.Next > 0 {
+			page += 1
+		} else {
+			break
+		}
+	}
+	return groups
+}