add pantheon migration state metrics (#4)

* support az aware hashring and multiple sts in one hashring (observatorium#129)

* support az aware hashring

* Update receive-controller.json

* support multiple statefulsets in 1 hashring

* add more logs

* style

* fix lint issue

* debug

* return when encountering error

* remove whitespace

* Fix k8s permissions (observatorium#133)

* Fix k8s permissions

* fix ci

* fix ci

* sync

* add pantheon migration state

* Revert "Fix k8s permissions (observatorium#133)"

This reverts commit e545b83.

---------

Co-authored-by: Alec Rajeev <13004609+alecrajeev@users.noreply.github.com>
Signed-off-by: Yi Jin <yi.jin@databricks.com>

.gitignore

@@ -4,3 +4,4 @@ vendor
 jsonnetfile.lock.json
 tmp
 .buildxcache
+.idea/

main.go

@@ -76,6 +76,7 @@ type CmdConfig struct {
 	ScaleTimeout           time.Duration
 	useAzAwareHashRing     bool
 	podAzAnnotationKey     string
+	migrationState         string
 }
 
 func parseFlags() CmdConfig {
@@ -98,6 +99,7 @@ func parseFlags() CmdConfig {
 	flag.DurationVar(&config.ScaleTimeout, "scale-timeout", defaultScaleTimeout, "A timeout to wait for receivers to really start after they report healthy")
 	flag.BoolVar(&config.useAzAwareHashRing, "use-az-aware-hashring", false, "A boolean to use az aware hashring to comply with Thanos v0.32+")
 	flag.StringVar(&config.podAzAnnotationKey, "pod-az-annotation-key", "", "pod annotation key for AZ Info, If not specified or key not found, will use sts name as AZ key")
+	flag.StringVar(&config.migrationState, "migration-state", "no-state", "[Databricks Internal] internal pantheon migration state info")
 	flag.Parse()
 
 	return config
@@ -160,7 +162,9 @@ func main() {
 			scaleTimeout:           config.ScaleTimeout,
 			useAzAwareHashRing:     config.useAzAwareHashRing,
 			podAzAnnotationKey:     config.podAzAnnotationKey,
+			migrationState:         config.migrationState,
 		}
+
 		c := newController(klient, logger, opt)
 		c.registerMetrics(reg)
 		done := make(chan struct{})
@@ -346,6 +350,7 @@ type options struct {
 	scaleTimeout           time.Duration
 	useAzAwareHashRing     bool
 	podAzAnnotationKey     string
+	migrationState         string
 }
 
 type controller struct {
@@ -368,6 +373,7 @@ type controller struct {
 	configmapLastSuccessfulChangeTime prometheus.Gauge
 	hashringNodes                     *prometheus.GaugeVec
 	hashringTenants                   *prometheus.GaugeVec
+	pantheonMigrationState            *prometheus.GaugeVec
 }
 
 func newController(klient kubernetes.Interface, logger log.Logger, o *options) *controller {
@@ -432,6 +438,13 @@ func newController(klient kubernetes.Interface, logger log.Logger, o *options) *
 			},
 			[]string{"name"},
 		),
+		pantheonMigrationState: prometheus.NewGaugeVec(
+			prometheus.GaugeOpts{
+				Name: "thanos_receive_controller_pantheon_migration_state",
+				Help: "pantheon migration state",
+			},
+			[]string{"migration_state"},
+		),
 	}
 }
 
@@ -446,6 +459,7 @@ func (c *controller) registerMetrics(reg *prometheus.Registry) {
 		c.configmapChangeErrors.WithLabelValues(create).Add(0)
 		c.configmapChangeErrors.WithLabelValues(update).Add(0)
 		c.configmapChangeErrors.WithLabelValues(other).Add(0)
+		c.pantheonMigrationState.WithLabelValues(c.options.migrationState).Add(1)
 		reg.MustRegister(
 			c.reconcileAttempts,
 			c.reconcileErrors,
@@ -455,6 +469,7 @@ func (c *controller) registerMetrics(reg *prometheus.Registry) {
 			c.configmapLastSuccessfulChangeTime,
 			c.hashringNodes,
 			c.hashringTenants,
+			c.pantheonMigrationState,
 		)
 	}
 }
@@ -533,6 +548,17 @@ func (c *controller) worker(ctx context.Context) {
 	}
 }
 
+func (c *controller) isProvisioned(statefulsets map[string][]*appsv1.StatefulSet) bool {
+	_, ok, err := c.cmapInf.GetStore().GetByKey(fmt.Sprintf("%s/%s", c.options.namespace, c.options.configMapGeneratedName))
+	if ok && err == nil {
+		level.Warn(c.logger).Log("msg", "could not fetch ConfigMap", "err", err)
+		// if the generated configmap is already present, we don't need to do anything
+		return true
+	}
+
+	return len(statefulsets) > 2 // at least 3 statefulsets need to be ready during provision
+}
+
 func (c *controller) sync(ctx context.Context) {
 	c.reconcileAttempts.Inc()
 	configMap, ok, err := c.cmapInf.GetStore().GetByKey(fmt.Sprintf("%s/%s", c.options.namespace, c.options.configMapName))
@@ -613,6 +639,12 @@ func (c *controller) sync(ctx context.Context) {
 		time.Sleep(c.options.scaleTimeout) // Give some time for all replicas before they receive hundreds req/s
 	}
 
+	if !c.isProvisioned(statefulsets) {
+		level.Error(c.logger).Log("msg", "not enough statefulsets found during provision",
+			"sts", fmt.Sprintf("%+v", statefulsets))
+		return
+	}
+
 	c.populate(ctx, hashrings, statefulsets)
 	level.Info(c.logger).Log("msg", "hashring populated", "hashring", fmt.Sprintf("%+v", hashrings))
 
@@ -632,7 +664,7 @@ func (c *controller) sync(ctx context.Context) {
 	}
 }
 
-func (c controller) waitForPod(ctx context.Context, name string) error {
+func (c *controller) waitForPod(ctx context.Context, name string) error {
 	//nolint:staticcheck
 	return wait.PollImmediate(time.Second, time.Minute, func() (bool, error) {
 		pod, err := c.klient.CoreV1().Pods(c.options.namespace).Get(ctx, name, metav1.GetOptions{})