[receiver/scraperhelper] exit before scraping if the receiver was shu…

…tdown (#11632)

#### Description
exit before scraping if the receiver was shutdown, do not wait the
initial delay.

.chloggen/initial_delay_shutdown.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: scraperhelper
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: If the scraper shuts down, do not scrape first.
+
+# One or more tracking issues or pull requests related to the change
+issues: [11632]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: |
+  When the scraper is shutting down, it currently will scrape at least once.
+  With this change, upon receiving a shutdown order, the receiver's scraperhelper will exit immediately.
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

receiver/scraperhelper/scrapercontroller.go

@@ -161,7 +161,12 @@ func (sc *controller) Shutdown(ctx context.Context) error {
 func (sc *controller) startScraping() {
 	go func() {
 		if sc.initialDelay > 0 {
-			<-time.After(sc.initialDelay)
+			select {
+			case <-time.After(sc.initialDelay):
+			case <-sc.done:
+				sc.terminated <- struct{}{}
+				return
+			}
 		}
 
 		if sc.tickerCh == nil {

receiver/scraperhelper/scrapercontroller_test.go

@@ -425,3 +425,37 @@ func TestScrapeControllerInitialDelay(t *testing.T) {
 
 	assert.NoError(t, r.Shutdown(context.Background()), "Must not error closing down")
 }
+
+func TestShutdownBeforeScrapeCanStart(t *testing.T) {
+	cfg := ControllerConfig{
+		CollectionInterval: time.Second,
+		InitialDelay:       5 * time.Second,
+	}
+
+	scp, err := NewScraper(component.MustNewType("timed"), func(context.Context) (pmetric.Metrics, error) {
+		// make the scraper wait for long enough it would disrupt a shutdown.
+		time.Sleep(30 * time.Second)
+		return pmetric.NewMetrics(), nil
+	})
+	require.NoError(t, err, "Must not error when creating scraper")
+
+	r, err := NewScraperControllerReceiver(
+		&cfg,
+		receivertest.NewNopSettings(),
+		new(consumertest.MetricsSink),
+		AddScraper(scp),
+	)
+	require.NoError(t, err, "Must not error when creating receiver")
+	require.NoError(t, r.Start(context.Background(), componenttest.NewNopHost()))
+	shutdown := make(chan struct{}, 1)
+	go func() {
+		assert.NoError(t, r.Shutdown(context.Background()))
+		close(shutdown)
+	}()
+	timer := time.NewTicker(10 * time.Second)
+	select {
+	case <-timer.C:
+		require.Fail(t, "shutdown should not wait for scraping")
+	case <-shutdown:
+	}
+}