Merge pull request #15082 from roidelapluie/notifystart

Notify web UI when starting up and shutting down

cmd/prometheus/main.go

@@ -76,9 +76,9 @@ import (
 	"github.com/prometheus/prometheus/tsdb/wlog"
 	"github.com/prometheus/prometheus/util/documentcli"
 	"github.com/prometheus/prometheus/util/logging"
+	"github.com/prometheus/prometheus/util/notifications"
 	prom_runtime "github.com/prometheus/prometheus/util/runtime"
 	"github.com/prometheus/prometheus/web"
-	"github.com/prometheus/prometheus/web/api"
 )
 
 var (
@@ -500,9 +500,10 @@ func main() {
 
 	logger := promlog.New(&cfg.promlogConfig)
 
-	notifs := api.NewNotifications(cfg.maxNotificationsSubscribers, prometheus.DefaultRegisterer)
+	notifs := notifications.NewNotifications(cfg.maxNotificationsSubscribers, prometheus.DefaultRegisterer)
 	cfg.web.NotificationsSub = notifs.Sub
 	cfg.web.NotificationsGetter = notifs.Get
+	notifs.AddNotification(notifications.StartingUp)
 
 	if err := cfg.setFeatureListOptions(logger); err != nil {
 		fmt.Fprintln(os.Stderr, fmt.Errorf("Error parsing feature list: %w", err))
@@ -989,6 +990,7 @@ func main() {
 			func(err error) {
 				close(cancel)
 				webHandler.SetReady(web.Stopping)
+				notifs.AddNotification(notifications.ShuttingDown)
 			},
 		)
 	}
@@ -1089,10 +1091,10 @@ func main() {
 
 		callback := func(success bool) {
 			if success {
-				notifs.DeleteNotification(api.ConfigurationUnsuccessful)
+				notifs.DeleteNotification(notifications.ConfigurationUnsuccessful)
 				return
 			}
-			notifs.AddNotification(api.ConfigurationUnsuccessful)
+			notifs.AddNotification(notifications.ConfigurationUnsuccessful)
 		}
 
 		g.Add(
@@ -1174,6 +1176,7 @@ func main() {
 				reloadReady.Close()
 
 				webHandler.SetReady(web.Ready)
+				notifs.DeleteNotification(notifications.StartingUp)
 				level.Info(logger).Log("msg", "Server is ready to receive web requests.")
 				<-cancel
 				return nil

util/notifications/notifications.go

@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package api
+package notifications
 
 import (
 	"sync"
@@ -22,6 +22,8 @@ import (
 
 const (
 	ConfigurationUnsuccessful = "Configuration reload has failed."
+	StartingUp                = "Prometheus is starting and replaying the write-ahead log (WAL)."
+	ShuttingDown              = "Prometheus is shutting down and gracefully stopping all operations."
 )
 
 // Notification represents an individual notification message.

util/notifications/notifications_test.go

@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package api
+package notifications
 
 import (
 	"sync"

web/api/v1/api.go

@@ -54,8 +54,8 @@ import (
 	"github.com/prometheus/prometheus/tsdb/index"
 	"github.com/prometheus/prometheus/util/annotations"
 	"github.com/prometheus/prometheus/util/httputil"
+	"github.com/prometheus/prometheus/util/notifications"
 	"github.com/prometheus/prometheus/util/stats"
-	"github.com/prometheus/prometheus/web/api"
 )
 
 type status string
@@ -214,8 +214,8 @@ type API struct {
 	gatherer            prometheus.Gatherer
 	isAgent             bool
 	statsRenderer       StatsRenderer
-	notificationsGetter func() []api.Notification
-	notificationsSub    func() (<-chan api.Notification, func(), bool)
+	notificationsGetter func() []notifications.Notification
+	notificationsSub    func() (<-chan notifications.Notification, func(), bool)
 
 	remoteWriteHandler http.Handler
 	remoteReadHandler  http.Handler
@@ -249,8 +249,8 @@ func NewAPI(
 	corsOrigin *regexp.Regexp,
 	runtimeInfo func() (RuntimeInfo, error),
 	buildInfo *PrometheusVersion,
-	notificationsGetter func() []api.Notification,
-	notificationsSub func() (<-chan api.Notification, func(), bool),
+	notificationsGetter func() []notifications.Notification,
+	notificationsSub func() (<-chan notifications.Notification, func(), bool),
 	gatherer prometheus.Gatherer,
 	registerer prometheus.Registerer,
 	statsRenderer StatsRenderer,

web/web.go

@@ -59,7 +59,7 @@ import (
 	"github.com/prometheus/prometheus/template"
 	"github.com/prometheus/prometheus/util/httputil"
 	"github.com/prometheus/prometheus/util/netconnlimit"
-	"github.com/prometheus/prometheus/web/api"
+	"github.com/prometheus/prometheus/util/notifications"
 	api_v1 "github.com/prometheus/prometheus/web/api/v1"
 	"github.com/prometheus/prometheus/web/ui"
 )
@@ -267,8 +267,8 @@ type Options struct {
 	RuleManager           *rules.Manager
 	Notifier              *notifier.Manager
 	Version               *PrometheusVersion
-	NotificationsGetter   func() []api.Notification
-	NotificationsSub      func() (<-chan api.Notification, func(), bool)
+	NotificationsGetter   func() []notifications.Notification
+	NotificationsSub      func() (<-chan notifications.Notification, func(), bool)
 	Flags                 map[string]string
 
 	ListenAddresses            []string