Add nginx metrics to prometheus

controllers/nginx/pkg/cmd/controller/status.go

@@ -0,0 +1,99 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"regexp"
+	"strconv"
+)
+
+var (
+	ac      = regexp.MustCompile(`Active connections: (\d+)`)
+	sahr    = regexp.MustCompile(`(\d+)\s(\d+)\s(\d+)`)
+	reading = regexp.MustCompile(`Reading: (\d+)`)
+	writing = regexp.MustCompile(`Writing: (\d+)`)
+	waiting = regexp.MustCompile(`Waiting: (\d+)`)
+)
+
+type nginxStatus struct {
+	// Active total number of active connections
+	Active int
+	// Accepted total number of accepted client connections
+	Accepted int
+	// Handled total number of handled connections. Generally, the parameter value is the same as accepts unless some resource limits have been reached (for example, the worker_connections limit).
+	Handled int
+	// Requests total number of client requests.
+	Requests int
+	// Reading current number of connections where nginx is reading the request header.
+	Reading int
+	// Writing current number of connections where nginx is writing the response back to the client.
+	Writing int
+	// Waiting current number of idle client connections waiting for a request.
+	Waiting int
+}
+
+func getNginxStatus() (*nginxStatus, error) {
+	resp, err := http.DefaultClient.Get(fmt.Sprintf("http://localhost:%v%v", ngxHealthPort, ngxStatusPath))
+	if err != nil {
+		return nil, fmt.Errorf("unexpected error scraping nginx status page: %v", err)
+	}
+
+	data, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("unexpected error scraping nginx status page (%v)", err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode < 200 || resp.StatusCode >= 400 {
+		return nil, fmt.Errorf("unexpected error scraping nginx status page (status %v)", resp.StatusCode)
+	}
+
+	return parse(string(data)), nil
+}
+
+func parse(data string) *nginxStatus {
+	acr := ac.FindStringSubmatch(data)
+	sahrr := sahr.FindStringSubmatch(data)
+	readingr := reading.FindStringSubmatch(data)
+	writingr := writing.FindStringSubmatch(data)
+	waitingr := waiting.FindStringSubmatch(data)
+
+	return &nginxStatus{
+		toInt(acr, 1),
+		toInt(sahrr, 1),
+		toInt(sahrr, 2),
+		toInt(sahrr, 3),
+		toInt(readingr, 1),
+		toInt(writingr, 1),
+		toInt(waitingr, 1),
+	}
+}
+
+func toInt(data []string, pos int) int {
+	if len(data) == 0 {
+		return 0
+	}
+	if pos > len(data) {
+		return 0
+	}
+	if v, err := strconv.Atoi(data[pos]); err == nil {
+		return v
+	}
+	return 0
+}