func NewSocketCollector()

in internal/ingress/metric/collectors/socket.go [113:232]
103 lines of code
4 McCabe index (conditional complexity)

func NewSocketCollector(pod, namespace, class string, metricsPerHost bool, buckets HistogramBuckets) (*SocketCollector, error) {
	socket := "/tmp/prometheus-nginx.socket"
	// unix sockets must be unlink()ed before being used
	_ = syscall.Unlink(socket)

	listener, err := net.Listen("unix", socket)
	if err != nil {
		return nil, err
	}

	err = os.Chmod(socket, 0777) // #nosec
	if err != nil {
		return nil, err
	}

	constLabels := prometheus.Labels{
		"controller_namespace": namespace,
		"controller_class":     class,
		"controller_pod":       pod,
	}

	requestTags := requestTags
	if metricsPerHost {
		requestTags = append(requestTags, "host")
	}

	sc := &SocketCollector{
		listener: listener,

		metricsPerHost: metricsPerHost,

		responseTime: prometheus.NewHistogramVec(
			prometheus.HistogramOpts{
				Name:        "response_duration_seconds",
				Help:        "The time spent on receiving the response from the upstream server",
				Namespace:   PrometheusNamespace,
				ConstLabels: constLabels,
				Buckets:     buckets.TimeBuckets,
			},
			requestTags,
		),
		responseLength: prometheus.NewHistogramVec(
			prometheus.HistogramOpts{
				Name:        "response_size",
				Help:        "The response length (including request line, header, and request body)",
				Namespace:   PrometheusNamespace,
				ConstLabels: constLabels,
				Buckets:     buckets.LengthBuckets,
			},
			requestTags,
		),

		requestTime: prometheus.NewHistogramVec(
			prometheus.HistogramOpts{
				Name:        "request_duration_seconds",
				Help:        "The request processing time in milliseconds",
				Namespace:   PrometheusNamespace,
				ConstLabels: constLabels,
				Buckets:     buckets.TimeBuckets,
			},
			requestTags,
		),
		requestLength: prometheus.NewHistogramVec(
			prometheus.HistogramOpts{
				Name:        "request_size",
				Help:        "The request length (including request line, header, and request body)",
				Namespace:   PrometheusNamespace,
				Buckets:     buckets.LengthBuckets,
				ConstLabels: constLabels,
			},
			requestTags,
		),

		requests: prometheus.NewCounterVec(
			prometheus.CounterOpts{
				Name:        "requests",
				Help:        "The total number of client requests.",
				Namespace:   PrometheusNamespace,
				ConstLabels: constLabels,
			},
			requestTags,
		),

		bytesSent: prometheus.NewHistogramVec(
			prometheus.HistogramOpts{
				Name:        "bytes_sent",
				Help:        "The number of bytes sent to a client",
				Namespace:   PrometheusNamespace,
				Buckets:     buckets.SizeBuckets,
				ConstLabels: constLabels,
			},
			requestTags,
		),

		upstreamLatency: prometheus.NewSummaryVec(
			prometheus.SummaryOpts{
				Name:        "ingress_upstream_latency_seconds",
				Help:        "Upstream service latency per Ingress",
				Namespace:   PrometheusNamespace,
				ConstLabels: constLabels,
				Objectives:  defObjectives,
			},
			[]string{"ingress", "namespace", "service", "canary"},
		),
	}

	sc.metricMapping = map[string]interface{}{
		prometheus.BuildFQName(PrometheusNamespace, "", "request_duration_seconds"): sc.requestTime,
		prometheus.BuildFQName(PrometheusNamespace, "", "request_size"):             sc.requestLength,

		prometheus.BuildFQName(PrometheusNamespace, "", "response_duration_seconds"): sc.responseTime,
		prometheus.BuildFQName(PrometheusNamespace, "", "response_size"):             sc.responseLength,

		prometheus.BuildFQName(PrometheusNamespace, "", "bytes_sent"): sc.bytesSent,

		prometheus.BuildFQName(PrometheusNamespace, "", "ingress_upstream_latency_seconds"): sc.upstreamLatency,
	}

	return sc, nil
}