From a01a0d103924348fc2f76cd6d2cea8b20f6d71bd Mon Sep 17 00:00:00 2001
From: Kristoffer Dalby <kradalby@kradalby.no>
Date: Tue, 5 Oct 2021 16:24:46 +0000
Subject: [PATCH] Remove unstable update channel, replace with state updates

---
 app.go        |   6 +--
 machine.go    | 106 --------------------------------------------------
 namespaces.go |  19 +++------
 3 files changed, 7 insertions(+), 124 deletions(-)

diff --git a/app.go b/app.go
index 27b9672..a6e547f 100644
--- a/app.go
+++ b/app.go
@@ -65,9 +65,6 @@ type Headscale struct {
 	aclPolicy *ACLPolicy
 	aclRules  *[]tailcfg.FilterRule
 
-	clientsUpdateChannels     sync.Map
-	clientsUpdateChannelMutex sync.Mutex
-
 	lastStateChange sync.Map
 }
 
@@ -145,10 +142,9 @@ func (h *Headscale) expireEphemeralNodesWorker() {
 				if err != nil {
 					log.Error().Err(err).Str("machine", m.Name).Msg("🤮 Cannot delete ephemeral machine from the database")
 				}
-				updateRequestsFromNode.WithLabelValues("ephemeral-node-update").Inc()
-				h.notifyChangesToPeers(&m)
 			}
 		}
+		h.setLastStateChangeToNow(ns.Name)
 	}
 }
 
diff --git a/machine.go b/machine.go
index 7a9df2e..fcc8255 100644
--- a/machine.go
+++ b/machine.go
@@ -2,7 +2,6 @@ package headscale
 
 import (
 	"encoding/json"
-	"errors"
 	"fmt"
 	"sort"
 	"strconv"
@@ -214,111 +213,6 @@ func (m *Machine) GetHostInfo() (*tailcfg.Hostinfo, error) {
 	return &hostinfo, nil
 }
 
-func (h *Headscale) notifyChangesToPeers(m *Machine) {
-	peers, err := h.getPeers(m)
-	if err != nil {
-		log.Error().
-			Str("func", "notifyChangesToPeers").
-			Str("machine", m.Name).
-			Msgf("Error getting peers: %s", err)
-		return
-	}
-	for _, peer := range peers {
-		log.Info().
-			Str("func", "notifyChangesToPeers").
-			Str("machine", m.Name).
-			Str("peer", peer.Name).
-			Str("address", peer.IPAddress).
-			Msgf("Notifying peer %s (%s)", peer.Name, peer.IPAddress)
-		err := h.sendRequestOnUpdateChannel(&peer)
-		if err != nil {
-			log.Info().
-				Str("func", "notifyChangesToPeers").
-				Str("machine", m.Name).
-				Str("peer", peer.Name).
-				Msgf("Peer %s does not have an open update client, skipping.", peer.Name)
-			continue
-		}
-		log.Trace().
-			Str("func", "notifyChangesToPeers").
-			Str("machine", m.Name).
-			Str("peer", peer.Name).
-			Str("address", peer.IPAddress).
-			Msgf("Notified peer %s (%s)", peer.Name, peer.IPAddress)
-	}
-}
-
-func (h *Headscale) getOrOpenUpdateChannel(m *Machine) <-chan struct{} {
-	var updateChan chan struct{}
-	if storedChan, ok := h.clientsUpdateChannels.Load(m.ID); ok {
-		if unwrapped, ok := storedChan.(chan struct{}); ok {
-			updateChan = unwrapped
-		} else {
-			log.Error().
-				Str("handler", "openUpdateChannel").
-				Str("machine", m.Name).
-				Msg("Failed to convert update channel to struct{}")
-		}
-	} else {
-		log.Debug().
-			Str("handler", "openUpdateChannel").
-			Str("machine", m.Name).
-			Msg("Update channel not found, creating")
-
-		updateChan = make(chan struct{})
-		h.clientsUpdateChannels.Store(m.ID, updateChan)
-	}
-	return updateChan
-}
-
-func (h *Headscale) closeUpdateChannel(m *Machine) {
-	h.clientsUpdateChannelMutex.Lock()
-	defer h.clientsUpdateChannelMutex.Unlock()
-
-	if storedChan, ok := h.clientsUpdateChannels.Load(m.ID); ok {
-		if unwrapped, ok := storedChan.(chan struct{}); ok {
-			close(unwrapped)
-		}
-	}
-	h.clientsUpdateChannels.Delete(m.ID)
-}
-
-func (h *Headscale) sendRequestOnUpdateChannel(m *Machine) error {
-	h.clientsUpdateChannelMutex.Lock()
-	defer h.clientsUpdateChannelMutex.Unlock()
-
-	pUp, ok := h.clientsUpdateChannels.Load(uint64(m.ID))
-	if ok {
-		log.Info().
-			Str("func", "requestUpdate").
-			Str("machine", m.Name).
-			Msgf("Notifying peer %s", m.Name)
-
-		if update, ok := pUp.(chan struct{}); ok {
-			log.Trace().
-				Str("func", "requestUpdate").
-				Str("machine", m.Name).
-				Msgf("Update channel is %#v", update)
-
-			updateRequestsToNode.Inc()
-			update <- struct{}{}
-
-			log.Trace().
-				Str("func", "requestUpdate").
-				Str("machine", m.Name).
-				Msgf("Notified machine %s", m.Name)
-		}
-	} else {
-		err := errors.New("machine does not have an open update channel")
-		log.Info().
-			Str("func", "requestUpdate").
-			Str("machine", m.Name).
-			Msgf("Machine %s does not have an open update channel", m.Name)
-		return err
-	}
-	return nil
-}
-
 func (h *Headscale) isOutdated(m *Machine) bool {
 	err := h.UpdateMachine(m)
 	if err != nil {
diff --git a/namespaces.go b/namespaces.go
index 75b6eab..2bf62bb 100644
--- a/namespaces.go
+++ b/namespaces.go
@@ -176,24 +176,17 @@ func (h *Headscale) checkForNamespacesPendingUpdates() {
 		return
 	}
 
-	names := []string{}
-	err = json.Unmarshal([]byte(v), &names)
+	namespaces := []string{}
+	err = json.Unmarshal([]byte(v), &namespaces)
 	if err != nil {
 		return
 	}
-	for _, name := range names {
+	for _, namespace := range namespaces {
 		log.Trace().
 			Str("func", "RequestMapUpdates").
-			Str("machine", name).
-			Msg("Sending updates to nodes in namespace")
-		machines, err := h.ListMachinesInNamespace(name)
-		if err != nil {
-			continue
-		}
-		for _, m := range *machines {
-			updateRequestsFromNode.WithLabelValues("namespace-update").Inc()
-			h.notifyChangesToPeers(&m)
-		}
+			Str("machine", namespace).
+			Msg("Sending updates to nodes in namespacespace")
+		h.setLastStateChangeToNow(namespace)
 	}
 	newV, err := h.getValue("namespaces_pending_updates")
 	if err != nil {