Refactor docs; Add 'ipng_source_tag', add udp listener for nginx-ipng-stats plugin

cmd/collector/prom_test.go

@@ -110,6 +110,61 @@ func TestPromStoreServeHTTP(t *testing.T) {
 	}
 }
 
+func TestPromStoreSourceTagRollup(t *testing.T) {
+	ps := NewPromStore()
+	// same host, two tags; each tag should appear with its own series.
+	ps.Ingest(LogRecord{Website: "h", Method: "GET", Status: "200", BodyBytesSent: 100, SourceTag: "direct"})
+	ps.Ingest(LogRecord{Website: "h", Method: "GET", Status: "200", BodyBytesSent: 300, SourceTag: "cdn"})
+	ps.Ingest(LogRecord{Website: "h", Method: "GET", Status: "200", BodyBytesSent: 100, SourceTag: "cdn"})
+
+	req := httptest.NewRequest("GET", "/metrics", nil)
+	rec := httptest.NewRecorder()
+	ps.ServeHTTP(rec, req)
+	body := rec.Body.String()
+
+	checks := []string{
+		"# TYPE nginx_http_requests_by_source_total counter",
+		`nginx_http_requests_by_source_total{source_tag="direct"} 1`,
+		`nginx_http_requests_by_source_total{source_tag="cdn"} 2`,
+		"# TYPE nginx_http_response_body_bytes_by_source histogram",
+		`nginx_http_response_body_bytes_by_source_sum{source_tag="direct"} 100`,
+		`nginx_http_response_body_bytes_by_source_sum{source_tag="cdn"} 400`,
+		// host-series totals are unchanged (one row, counting 3 requests).
+		`nginx_http_requests_total{host="h",method="GET",status="200"} 3`,
+	}
+	for _, want := range checks {
+		if !strings.Contains(body, want) {
+			t.Errorf("missing %q in output:\n%s", want, body)
+		}
+	}
+}
+
+func TestPromStoreUDPCounters(t *testing.T) {
+	ps := NewPromStore()
+	ps.IncUDPPacket()
+	ps.IncUDPPacket()
+	ps.IncUDPPacket()
+	ps.IncUDPSuccess()
+	ps.IncUDPSuccess()
+	ps.IncUDPConsumed()
+
+	req := httptest.NewRequest("GET", "/metrics", nil)
+	rec := httptest.NewRecorder()
+	ps.ServeHTTP(rec, req)
+	body := rec.Body.String()
+
+	checks := []string{
+		"logtail_udp_packets_received_total 3",
+		"logtail_udp_loglines_success_total 2",
+		"logtail_udp_loglines_consumed_total 1",
+	}
+	for _, want := range checks {
+		if !strings.Contains(body, want) {
+			t.Errorf("missing %q in output:\n%s", want, body)
+		}
+	}
+}
+
 func TestPromStoreCounterCap(t *testing.T) {
 	ps := NewPromStore()
 	// Fill to cap with distinct {host,method,status} combos