chore: fix flake in listening ports test (#10833)

agent/agent.go

@@ -68,6 +68,7 @@ type Options struct {
 	EnvironmentVariables         map[string]string
 	Logger                       slog.Logger
 	IgnorePorts                  map[int]string
+	PortCacheDuration            time.Duration
 	SSHMaxTimeout                time.Duration
 	TailnetListenPort            uint16
 	Subsystems                   []codersdk.AgentSubsystem
@@ -126,6 +127,9 @@ func New(options Options) Agent {
 	if options.ServiceBannerRefreshInterval == 0 {
 		options.ServiceBannerRefreshInterval = 2 * time.Minute
 	}
+	if options.PortCacheDuration == 0 {
+		options.PortCacheDuration = 1 * time.Second
+	}
 
 	prometheusRegistry := options.PrometheusRegistry
 	if prometheusRegistry == nil {
@@ -153,6 +157,7 @@ func New(options Options) Agent {
 		lifecycleReported:            make(chan codersdk.WorkspaceAgentLifecycle, 1),
 		lifecycleStates:              []agentsdk.PostLifecycleRequest{{State: codersdk.WorkspaceAgentLifecycleCreated}},
 		ignorePorts:                  options.IgnorePorts,
+		portCacheDuration:            options.PortCacheDuration,
 		connStatsChan:                make(chan *agentsdk.Stats, 1),
 		reportMetadataInterval:       options.ReportMetadataInterval,
 		serviceBannerRefreshInterval: options.ServiceBannerRefreshInterval,
@@ -181,8 +186,9 @@ type agent struct {
 	// ignorePorts tells the api handler which ports to ignore when
 	// listing all listening ports. This is helpful to hide ports that
 	// are used by the agent, that the user does not care about.
-	ignorePorts map[int]string
-	subsystems  []codersdk.AgentSubsystem
+	ignorePorts       map[int]string
+	portCacheDuration time.Duration
+	subsystems        []codersdk.AgentSubsystem
 
 	reconnectingPTYs       sync.Map
 	reconnectingPTYTimeout time.Duration

agent/api.go

@@ -26,17 +26,27 @@ func (a *agent) apiHandler() http.Handler {
 		cpy[k] = b
 	}
 
-	lp := &listeningPortsHandler{ignorePorts: cpy}
+	cacheDuration := 1 * time.Second
+	if a.portCacheDuration > 0 {
+		cacheDuration = a.portCacheDuration
+	}
+
+	lp := &listeningPortsHandler{
+		ignorePorts:   cpy,
+		cacheDuration: cacheDuration,
+	}
 	r.Get("/api/v0/listening-ports", lp.handler)
 
 	return r
 }
 
 type listeningPortsHandler struct {
-	mut         sync.Mutex
-	ports       []codersdk.WorkspaceAgentListeningPort
-	mtime       time.Time
-	ignorePorts map[int]string
+	ignorePorts   map[int]string
+	cacheDuration time.Duration
+
+	mut   sync.Mutex
+	ports []codersdk.WorkspaceAgentListeningPort
+	mtime time.Time
 }
 
 // handler returns a list of listening ports. This is tested by coderd's

agent/ports_supported.go

@@ -15,7 +15,7 @@ func (lp *listeningPortsHandler) getListeningPorts() ([]codersdk.WorkspaceAgentL
 	lp.mut.Lock()
 	defer lp.mut.Unlock()
 
-	if time.Since(lp.mtime) < time.Second {
+	if time.Since(lp.mtime) < lp.cacheDuration {
 		// copy
 		ports := make([]codersdk.WorkspaceAgentListeningPort, len(lp.ports))
 		copy(ports, lp.ports)