diff --git a/stackdriver_exporter.go b/stackdriver_exporter.go index 324c0bad..e46d2f09 100644 --- a/stackdriver_exporter.go +++ b/stackdriver_exporter.go @@ -109,35 +109,59 @@ func createMonitoringService(ctx context.Context) (*monitoring.Service, error) { return monitoringService, nil } -func newHandler(projectIDs []string, m *monitoring.Service, logger log.Logger) http.HandlerFunc { - return func(w http.ResponseWriter, r *http.Request) { - collectParams := r.URL.Query()["collect"] - - // Create filters for "collect" query parameters. - filters := make(map[string]bool) - for _, param := range collectParams { - filters[param] = true - } +type handler struct { + handler http.Handler + logger log.Logger - registry := prometheus.NewRegistry() + projectIDs []string + m *monitoring.Service +} - for _, project := range projectIDs { - monitoringCollector, err := collectors.NewMonitoringCollector(project, m, filters, logger) - if err != nil { - level.Error(logger).Log("err", err) - os.Exit(1) - } - registry.MustRegister(monitoringCollector) - } +func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) { + collectParams := r.URL.Query()["collect"] + filters := make(map[string]bool) + for _, param := range collectParams { + filters[param] = true + } + + if len(filters) > 0 { + h.innerHandler(filters).ServeHTTP(w, r) + return + } + + h.handler.ServeHTTP(w, r) +} + +func newHandler(projectIDs []string, m *monitoring.Service, logger log.Logger) *handler { + h := &handler{ + logger: logger, + projectIDs: projectIDs, + m: m, + } + + h.handler = h.innerHandler(nil) + return h +} - gatherers := prometheus.Gatherers{ - prometheus.DefaultGatherer, - registry, +func (h *handler) innerHandler(filters map[string]bool) http.Handler { + registry := prometheus.NewRegistry() + + for _, project := range h.projectIDs { + monitoringCollector, err := collectors.NewMonitoringCollector(project, h.m, filters, h.logger) + if err != nil { + level.Error(h.logger).Log("err", err) + os.Exit(1) } - // Delegate http serving to Prometheus client library, which will call collector.Collect. - h := promhttp.HandlerFor(gatherers, promhttp.HandlerOpts{}) - h.ServeHTTP(w, r) + registry.MustRegister(monitoringCollector) + } + + gatherers := prometheus.Gatherers{ + prometheus.DefaultGatherer, + registry, } + + // Delegate http serving to Prometheus client library, which will call collector.Collect. + return promhttp.HandlerFor(gatherers, promhttp.HandlerOpts{}) } func main() { @@ -172,9 +196,9 @@ func main() { } projectIDs := strings.Split(*projectID, ",") - handlerFunc := newHandler(projectIDs, monitoringService, logger) + handler := newHandler(projectIDs, monitoringService, logger) - http.Handle(*metricsPath, promhttp.InstrumentMetricHandler(prometheus.DefaultRegisterer, handlerFunc)) + http.Handle(*metricsPath, promhttp.InstrumentMetricHandler(prometheus.DefaultRegisterer, handler)) http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) { w.Write([]byte(` Stackdriver Exporter