Add a statistics pane to the webhook page (closes #368)

The webhook page opens with a statistics pane: entrypoints and targets, deliveries in progress, the last arrival, the retention period; events, deliveries and failures, lifetime and within retention; and events, failures and failure percentage over 10 minutes and 24 hours.

Running totals, one row per target plus one for events, sit in each webhook's event database and are written in the same transaction as the rows they count; retention prunes in paused, stoppable batches and subtracts what it removes. Window figures are index-range counts on a new finished_at column. An existing event database must be recreated.

Model: opus-5-5

internal/delivery/delivery_totals_test.go

@@ -0,0 +1,177 @@
+package delivery_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gorm.io/gorm"
+	"sneak.berlin/go/webhooker/internal/database"
+)
+
+// targetTotals reads one target's totals from a webhook database, all
+// zero when it has no row.
+func targetTotals(
+	t *testing.T, db *gorm.DB, targetID string,
+) database.TargetTotals {
+	t.Helper()
+
+	var rows []database.TargetTotals
+
+	require.NoError(t, db.Where("target_id = ?", targetID).
+		Find(&rows).Error)
+
+	if len(rows) == 0 {
+		return database.TargetTotals{TargetID: targetID}
+	}
+
+	return rows[0]
+}
+
+// TestUpdateDeliveryStatus_FinishTimeAndTargetTotals pins what a status
+// write records for the webhook page's statistics: the time a delivery
+// finished, set only when it becomes delivered or failed, and one more
+// on its target's delivered or failed total.
+func TestUpdateDeliveryStatus_FinishTimeAndTargetTotals(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		status    database.DeliveryStatus
+		finished  bool
+		delivered int64
+		failed    int64
+	}{
+		{database.DeliveryStatusRetrying, false, 0, 0},
+		{database.DeliveryStatusDelivered, true, 1, 0},
+		{database.DeliveryStatusFailed, true, 0, 1},
+	}
+
+	for _, tt := range tests {
+		t.Run(string(tt.status), func(t *testing.T) {
+			t.Parallel()
+
+			db := testWebhookDB(t)
+			e := testEngine(t, 1)
+			event := seedEvent(t, db, `{}`)
+			targetID := uuid.New().String()
+			d := seedDelivery(
+				t, db, event.ID, targetID,
+				database.DeliveryStatusPending,
+			)
+
+			before := time.Now()
+
+			require.NoError(t, e.ExportUpdateDeliveryStatus(
+				db, &d, tt.status,
+			))
+
+			var stored database.Delivery
+
+			require.NoError(t, db.First(&stored, "id = ?", d.ID).Error)
+			assert.Equal(t, tt.status, stored.Status)
+
+			if tt.finished {
+				require.NotNil(t, stored.FinishedAt)
+				assert.False(t, stored.FinishedAt.Before(before))
+			} else {
+				assert.Nil(t, stored.FinishedAt)
+			}
+
+			assert.Equal(t, database.TargetTotals{
+				TargetID:  targetID,
+				Delivered: tt.delivered,
+				Failed:    tt.failed,
+			}, targetTotals(t, db, targetID))
+		})
+	}
+}
+
+// TestUpdateDeliveryStatus_DeletedDeliveryIsNotCounted covers a
+// delivery retention deleted while the engine still held it. Failing
+// it afterwards writes no row, so it adds no failure either: retention
+// has already counted what it removed.
+func TestUpdateDeliveryStatus_DeletedDeliveryIsNotCounted(t *testing.T) {
+	t.Parallel()
+
+	db := testWebhookDB(t)
+	e := testEngine(t, 1)
+	event := seedEvent(t, db, `{}`)
+	targetID := uuid.New().String()
+	d := seedDelivery(
+		t, db, event.ID, targetID,
+		database.DeliveryStatusRetrying,
+	)
+
+	require.NoError(t, db.Unscoped().
+		Delete(&database.Delivery{}, "id = ?", d.ID).Error)
+
+	require.NoError(t, e.ExportUpdateDeliveryStatus(
+		db, &d, database.DeliveryStatusFailed,
+	))
+
+	assert.Equal(t, database.TargetTotals{TargetID: targetID},
+		targetTotals(t, db, targetID))
+}
+
+// TestUpdateDeliveryStatus_FinishedDeliveryIsNotSettledAgain covers a
+// delivery settled a second time, as recovery can do when a worker has
+// settled it since recovery read it. Neither status writes over the
+// first, and the totals do not move.
+func TestUpdateDeliveryStatus_FinishedDeliveryIsNotSettledAgain(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	finished := []database.DeliveryStatus{
+		database.DeliveryStatusDelivered,
+		database.DeliveryStatusFailed,
+	}
+
+	for _, first := range finished {
+		t.Run(string(first), func(t *testing.T) {
+			t.Parallel()
+
+			db := testWebhookDB(t)
+			e := testEngine(t, 1)
+			event := seedEvent(t, db, `{}`)
+			targetID := uuid.New().String()
+			d := seedDelivery(
+				t, db, event.ID, targetID,
+				database.DeliveryStatusRetrying,
+			)
+
+			// The delivery as recovery read it, before the worker
+			// settled it.
+			readBefore := d
+
+			require.NoError(t, e.ExportUpdateDeliveryStatus(
+				db, &d, first,
+			))
+
+			var settled database.Delivery
+
+			require.NoError(t, db.First(&settled, "id = ?", d.ID).Error)
+			require.NotNil(t, settled.FinishedAt)
+
+			totals := targetTotals(t, db, targetID)
+
+			for _, again := range finished {
+				stale := readBefore
+
+				require.NoError(t, e.ExportUpdateDeliveryStatus(
+					db, &stale, again,
+				))
+			}
+
+			var stored database.Delivery
+
+			require.NoError(t, db.First(&stored, "id = ?", d.ID).Error)
+			assert.Equal(t, first, stored.Status)
+			require.NotNil(t, stored.FinishedAt)
+			assert.True(t, settled.FinishedAt.Equal(*stored.FinishedAt))
+			assert.Equal(t, totals, targetTotals(t, db, targetID))
+		})
+	}
+}