[receiver/azureeventhub] Fix memory leak on shutdown (#32401)

**Description:** <Describe what has changed.>
<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
As explained
[here](#30438 (comment)),
components need to cancel all their work and background tasks before
returning from `Shutdown`. My original [change for this
component](#32364)
to add `goleak` testing worked around the proper behavior. This PR fully
addresses the `Shutdown` functionality to ensure the component behaves
the way the spec requires.

**Link to tracking Issue:** <Issue number if applicable>
#30438

**Testing:** <Describe what testing was performed and which tests were
added.>
Tests are passing.

.chloggen/goleak_azureeventhubrec_fix.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. filelogreceiver)
+component: azureeventhubreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Fix memory leak on shutdown
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [32401]
+
+# (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:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# 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/azureeventhubreceiver/eventhubhandler.go

@@ -53,12 +53,14 @@ type eventhubHandler struct {
 	dataConsumer dataConsumer
 	config       *Config
 	settings     receiver.CreateSettings
+	cancel       context.CancelFunc
 }
 
 // Implement eventHandler Interface
 var _ eventHandler = (*eventhubHandler)(nil)
 
 func (h *eventhubHandler) run(ctx context.Context, host component.Host) error {
+	ctx, h.cancel = context.WithCancel(ctx)
 
 	storageClient, err := adapter.GetStorageClient(ctx, host, h.config.StorageID, h.settings.ID)
 	if err != nil {
@@ -177,6 +179,10 @@ func (h *eventhubHandler) close(ctx context.Context) error {
 		}
 		h.hub = nil
 	}
+	if h.cancel != nil {
+		h.cancel()
+	}
+
 	return nil
 }
 

receiver/azureeventhubreceiver/eventhubhandler_test.go

@@ -84,9 +84,6 @@ func (m *mockDataConsumer) consume(ctx context.Context, event *eventhub.Event) e
 }
 
 func TestEventhubHandler_Start(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
 	config := createDefaultConfig()
 	config.(*Config).Connection = "Endpoint=sb://namespace.servicebus.windows.net/;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=superSecret1234=;EntityPath=hubName"
 
@@ -97,17 +94,11 @@ func TestEventhubHandler_Start(t *testing.T) {
 	}
 	ehHandler.hub = &mockHubWrapper{}
 
-	err := ehHandler.run(ctx, componenttest.NewNopHost())
-	assert.NoError(t, err)
-
-	err = ehHandler.close(ctx)
-	assert.NoError(t, err)
+	assert.NoError(t, ehHandler.run(context.Background(), componenttest.NewNopHost()))
+	assert.NoError(t, ehHandler.close(context.Background()))
 }
 
 func TestEventhubHandler_newMessageHandler(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
 	config := createDefaultConfig()
 	config.(*Config).Connection = "Endpoint=sb://namespace.servicebus.windows.net/;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=superSecret1234=;EntityPath=hubName"
 
@@ -131,11 +122,10 @@ func TestEventhubHandler_newMessageHandler(t *testing.T) {
 	}
 	ehHandler.hub = &mockHubWrapper{}
 
-	err = ehHandler.run(ctx, componenttest.NewNopHost())
-	assert.NoError(t, err)
+	assert.NoError(t, ehHandler.run(context.Background(), componenttest.NewNopHost()))
 
 	now := time.Now()
-	err = ehHandler.newMessageHandler(ctx, &eventhub.Event{
+	err = ehHandler.newMessageHandler(context.Background(), &eventhub.Event{
 		Data:         []byte("hello"),
 		PartitionKey: nil,
 		Properties:   map[string]any{"foo": "bar"},
@@ -158,4 +148,5 @@ func TestEventhubHandler_newMessageHandler(t *testing.T) {
 	read, ok := sink.AllLogs()[0].ResourceLogs().At(0).ScopeLogs().At(0).LogRecords().At(0).Attributes().Get("foo")
 	assert.True(t, ok)
 	assert.Equal(t, "bar", read.AsString())
+	assert.NoError(t, ehHandler.close(context.Background()))
 }