a bit more safety by copying the state when passing it to

the websessions and prometheus.

cmd/converge/notifier.go

@@ -15,6 +15,6 @@ func NewStateNotifier() *StateNotifier {
 }
 
 func (notifier StateNotifier) Publish(state *models.State) {
-	notifier.webNotificationChannel <- state
+	notifier.webNotificationChannel <- state.Copy()
-	notifier.prometheusNotificationChannel <- state
+	notifier.prometheusNotificationChannel <- state.Copy()
 }

pkg/models/state.go

@@ -1,6 +1,18 @@
 package models
 
+// State is a description of the current state of converge.
+// Created by the server and used for updating the web client
+// and prometheus metrics.
 type State struct {
 	Agents  []Agent
 	Clients []Client
 }
+
+func (state *State) Copy() *State {
+	c := State{}
+	c.Agents = make([]Agent, len(state.Agents))
+	c.Clients = make([]Client, len(state.Clients))
+	copy(c.Agents, state.Agents)
+	copy(c.Clients, state.Clients)
+	return &c
+}