hub: add debug logs for smart behavior (#1800)

this is so people trying to get smart working can see the config changes immediately. not need to wait for the smart interval.

internal/hub/systems/system.go

@@ -145,6 +145,7 @@ func (sys *System) update() error {
 		// update smart interval if it's set on the agent side
 		if data.Details.SmartInterval > 0 {
 			sys.smartInterval = data.Details.SmartInterval
+			sys.manager.hub.Logger().Info("SMART interval updated from agent details", "system", sys.Id, "interval", sys.smartInterval.String())
 			// make sure we reset expiration of lastFetch to remain as long as the new smart interval
 			// to prevent premature expiration leading to new fetch if interval is different.
 			sys.manager.smartFetchMap.UpdateExpiration(sys.Id, sys.smartInterval+time.Minute)
@@ -156,11 +157,10 @@ func (sys *System) update() error {
 		if sys.smartInterval <= 0 {
 			sys.smartInterval = time.Hour
 		}
-		lastFetch, _ := sys.manager.smartFetchMap.GetOk(sys.Id)
-		if time.Since(time.UnixMilli(lastFetch-1e4)) >= sys.smartInterval && sys.smartFetching.CompareAndSwap(false, true) {
+		if sys.shouldFetchSmart() && sys.smartFetching.CompareAndSwap(false, true) {
+			sys.manager.hub.Logger().Info("SMART fetch", "system", sys.Id, "interval", sys.smartInterval.String())
 			go func() {
 				defer sys.smartFetching.Store(false)
-				sys.manager.smartFetchMap.Set(sys.Id, time.Now().UnixMilli(), sys.smartInterval+time.Minute)
 				_ = sys.FetchAndSaveSmartDevices()
 			}()
 		}
@@ -643,6 +643,7 @@ func (s *System) createSSHClient() error {
 		return err
 	}
 	s.agentVersion, _ = extractAgentVersion(string(s.client.Conn.ServerVersion()))
+	s.manager.resetFailedSmartFetchState(s.Id)
 	return nil
 }
 

internal/hub/systems/system_manager.go

@@ -44,7 +44,7 @@ type SystemManager struct {
 	hub           hubLike                       // Hub interface for database and alert operations
 	systems       *store.Store[string, *System] // Thread-safe store of active systems
 	sshConfig     *ssh.ClientConfig             // SSH client configuration for system connections
-	smartFetchMap *expirymap.ExpiryMap[int64]   // Stores last SMART fetch time per system ID
+	smartFetchMap *expirymap.ExpiryMap[bool]    // Stores whether the last SMART fetch succeeded while entry TTL enforces fetch interval
 }
 
 // hubLike defines the interface requirements for the hub dependency.
@@ -62,7 +62,7 @@ func NewSystemManager(hub hubLike) *SystemManager {
 	return &SystemManager{
 		systems:       store.New(map[string]*System{}),
 		hub:           hub,
-		smartFetchMap: expirymap.New[int64](time.Hour),
+		smartFetchMap: expirymap.New[bool](time.Hour),
 	}
 }
 
@@ -306,6 +306,7 @@ func (sm *SystemManager) AddWebSocketSystem(systemId string, agentVersion semver
 	if err != nil {
 		return err
 	}
+	sm.resetFailedSmartFetchState(systemId)
 
 	system := sm.NewSystem(systemId)
 	system.WsConn = wsConn
@@ -317,6 +318,15 @@ func (sm *SystemManager) AddWebSocketSystem(systemId string, agentVersion semver
 	return nil
 }
 
+// resetFailedSmartFetchState clears only failed SMART cooldown entries so a fresh
+// agent reconnect retries SMART discovery immediately after configuration changes.
+func (sm *SystemManager) resetFailedSmartFetchState(systemID string) {
+	succeeded, ok := sm.smartFetchMap.GetOk(systemID)
+	if ok && !succeeded {
+		sm.smartFetchMap.Remove(systemID)
+	}
+}
+
 // createSSHClientConfig initializes the SSH client configuration for connecting to an agent's server
 func (sm *SystemManager) createSSHClientConfig() error {
 	privateKey, err := sm.hub.GetSSHKey("")

internal/hub/systems/system_smart.go

@@ -4,6 +4,7 @@ import (
 	"database/sql"
 	"errors"
 	"strings"
+	"time"
 
 	"github.com/henrygd/beszel/internal/entities/smart"
 	"github.com/pocketbase/pocketbase/core"
@@ -12,10 +13,44 @@ import (
 // FetchAndSaveSmartDevices fetches SMART data from the agent and saves it to the database
 func (sys *System) FetchAndSaveSmartDevices() error {
 	smartData, err := sys.FetchSmartDataFromAgent()
-	if err != nil || len(smartData) == 0 {
+	if err != nil {
+		sys.recordSmartFetchResult(err, 0)
 		return err
 	}
-	return sys.saveSmartDevices(smartData)
+	err = sys.saveSmartDevices(smartData)
+	sys.recordSmartFetchResult(err, len(smartData))
+	return err
+}
+
+// recordSmartFetchResult stores a cooldown entry for the SMART interval and marks
+// whether the last fetch produced any devices, so failed setup can retry on reconnect.
+func (sys *System) recordSmartFetchResult(err error, deviceCount int) {
+	if sys.manager == nil {
+		return
+	}
+	interval := sys.smartFetchInterval()
+	success := err == nil && deviceCount > 0
+	if sys.manager.hub != nil {
+		sys.manager.hub.Logger().Info("SMART fetch result", "system", sys.Id, "success", success, "devices", deviceCount, "interval", interval.String(), "err", err)
+	}
+	sys.manager.smartFetchMap.Set(sys.Id, success, interval+time.Minute)
+}
+
+// shouldFetchSmart returns true when there is no active SMART cooldown entry for this system.
+func (sys *System) shouldFetchSmart() bool {
+	if sys.manager == nil {
+		return true
+	}
+	_, ok := sys.manager.smartFetchMap.GetOk(sys.Id)
+	return !ok
+}
+
+// smartFetchInterval returns the agent-provided SMART interval or the default when unset.
+func (sys *System) smartFetchInterval() time.Duration {
+	if sys.smartInterval > 0 {
+		return sys.smartInterval
+	}
+	return time.Hour
 }
 
 // saveSmartDevices saves SMART device data to the smart_devices collection

internal/hub/systems/system_smart_test.go

@@ -0,0 +1,75 @@
+//go:build testing
+
+package systems
+
+import (
+	"errors"
+	"testing"
+	"time"
+
+	"github.com/henrygd/beszel/internal/hub/expirymap"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRecordSmartFetchResult(t *testing.T) {
+	sm := &SystemManager{smartFetchMap: expirymap.New[bool](time.Hour)}
+	t.Cleanup(sm.smartFetchMap.StopCleaner)
+
+	sys := &System{
+		Id:            "system-1",
+		manager:       sm,
+		smartInterval: time.Hour,
+	}
+
+	// Successful fetch with devices
+	sys.recordSmartFetchResult(nil, 5)
+	succeeded, ok := sm.smartFetchMap.GetOk(sys.Id)
+	assert.True(t, ok, "expected smart fetch result to be stored")
+	assert.True(t, succeeded, "expected successful fetch state to be recorded")
+
+	// Failed fetch
+	sys.recordSmartFetchResult(errors.New("failed"), 0)
+	succeeded, ok = sm.smartFetchMap.GetOk(sys.Id)
+	assert.True(t, ok, "expected failed smart fetch state to be stored")
+	assert.False(t, succeeded, "expected failed smart fetch state to be marked unsuccessful")
+
+	// Successful fetch but no devices
+	sys.recordSmartFetchResult(nil, 0)
+	succeeded, ok = sm.smartFetchMap.GetOk(sys.Id)
+	assert.True(t, ok, "expected fetch with zero devices to be stored")
+	assert.False(t, succeeded, "expected fetch with zero devices to be marked unsuccessful")
+}
+
+func TestShouldFetchSmart(t *testing.T) {
+	sm := &SystemManager{smartFetchMap: expirymap.New[bool](time.Hour)}
+	t.Cleanup(sm.smartFetchMap.StopCleaner)
+
+	sys := &System{
+		Id:            "system-1",
+		manager:       sm,
+		smartInterval: time.Hour,
+	}
+
+	assert.True(t, sys.shouldFetchSmart(), "expected initial smart fetch to be allowed")
+
+	sys.recordSmartFetchResult(errors.New("failed"), 0)
+	assert.False(t, sys.shouldFetchSmart(), "expected smart fetch to be blocked while interval entry exists")
+
+	sm.smartFetchMap.Remove(sys.Id)
+	assert.True(t, sys.shouldFetchSmart(), "expected smart fetch to be allowed after interval entry is cleared")
+}
+
+func TestResetFailedSmartFetchState(t *testing.T) {
+	sm := &SystemManager{smartFetchMap: expirymap.New[bool](time.Hour)}
+	t.Cleanup(sm.smartFetchMap.StopCleaner)
+
+	sm.smartFetchMap.Set("system-1", false, time.Hour)
+	sm.resetFailedSmartFetchState("system-1")
+	_, ok := sm.smartFetchMap.GetOk("system-1")
+	assert.False(t, ok, "expected failed smart fetch state to be cleared on reconnect")
+
+	sm.smartFetchMap.Set("system-1", true, time.Hour)
+	sm.resetFailedSmartFetchState("system-1")
+	_, ok = sm.smartFetchMap.GetOk("system-1")
+	assert.True(t, ok, "expected successful smart fetch state to be preserved")
+}