Implement graceful shutdown of agent.DataAccess (#1008)

* Implements graceful shutdown of agent.DataAccess and underlying Datastore/Logstore/MessageQueue

* adds tests for closing agent.DataAccess and Datastore

api/datastore/internal/datastoreutil/metrics.go

@@ -116,3 +116,8 @@ func (m *metricds) GetLog(ctx context.Context, appName, callID string) (io.Reade
 
 // instant & no context ;)
 func (m *metricds) GetDatabase() *sqlx.DB { return m.ds.GetDatabase() }
+
+// Close calls Close on the underlying Datastore
+func (m *metricds) Close() error {
+	return m.ds.Close()
+}

api/datastore/mock.go

@@ -198,3 +198,7 @@ func (m *mock) batchDeleteRoutes(ctx context.Context, appID string) error {
 func (m *mock) GetDatabase() *sqlx.DB {
 	return nil
 }
+
+func (m *mock) Close() error {
+	return nil
+}

api/datastore/sql/sql.go

@@ -910,3 +910,8 @@ func buildFilterCallQuery(filter *models.CallFilter) (string, []interface{}) {
 func (ds *sqlStore) GetDatabase() *sqlx.DB {
 	return ds.db
 }
+
+// Close closes the database, releasing any open resources.
+func (ds *sqlStore) Close() error {
+	return ds.db.Close()
+}

api/datastore/sql/sql_test.go

@@ -127,4 +127,23 @@ func TestDatastore(t *testing.T) {
 
 		both(u)
 	}
+
+}
+
+func TestClose(t *testing.T) {
+	ctx := context.Background()
+	defer os.RemoveAll("sqlite_test_dir")
+	u, err := url.Parse("sqlite3://sqlite_test_dir")
+	if err != nil {
+		t.Fatal(err)
+	}
+	os.RemoveAll("sqlite_test_dir")
+	ds, err := newDS(ctx, u)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if err := ds.Close(); err != nil {
+		t.Fatalf("Failed to close datastore: %v", err)
+	}
 }