Add nginx metrics to prometheus

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

@@ -0,0 +1,233 @@
+/*
+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 (
+	"path/filepath"
+
+	"github.com/golang/glog"
+
+	common "github.com/ncabatoff/process-exporter"
+	"github.com/ncabatoff/process-exporter/proc"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+type exeMatcher struct {
+	name string
+	args []string
+}
+
+func (em exeMatcher) MatchAndName(nacl common.NameAndCmdline) (bool, string) {
+	if len(nacl.Cmdline) == 0 {
+		return false, ""
+	}
+	cmd := filepath.Base(nacl.Cmdline[0])
+	return em.name == cmd, ""
+}
+
+func (n *NGINXController) setupMonitor(args []string) {
+	pc, err := newProcessCollector(true, exeMatcher{"nginx", args})
+	if err != nil {
+		glog.Fatalf("unexpedted error registering nginx collector: %v", err)
+	}
+	err = prometheus.Register(pc)
+	if err != nil {
+		glog.Warningf("unexpected error registering nginx collector: %v", err)
+	}
+}
+
+var (
+	numprocsDesc = prometheus.NewDesc(
+		"nginx_num_procs",
+		"number of processes",
+		nil, nil)
+
+	cpuSecsDesc = prometheus.NewDesc(
+		"nginx_cpu_seconds_total",
+		"Cpu usage in seconds",
+		nil, nil)
+
+	readBytesDesc = prometheus.NewDesc(
+		"nginx_read_bytes_total",
+		"number of bytes read",
+		nil, nil)
+
+	writeBytesDesc = prometheus.NewDesc(
+		"nginx_write_bytes_total",
+		"number of bytes written",
+		nil, nil)
+
+	memResidentbytesDesc = prometheus.NewDesc(
+		"nginx_resident_memory_bytes",
+		"number of bytes of memory in use",
+		nil, nil)
+
+	memVirtualbytesDesc = prometheus.NewDesc(
+		"nginx_virtual_memory_bytes",
+		"number of bytes of memory in use",
+		nil, nil)
+
+	startTimeDesc = prometheus.NewDesc(
+		"nginx_oldest_start_time_seconds",
+		"start time in seconds since 1970/01/01",
+		nil, nil)
+
+	activeDesc = prometheus.NewDesc(
+		"nginx_active_connections",
+		"total number of active connections",
+		nil, nil)
+
+	acceptedDesc = prometheus.NewDesc(
+		"nginx_accepted_connections",
+		"total number of accepted client connections",
+		nil, nil)
+
+	handledDesc = prometheus.NewDesc(
+		"nginx_handled_connections",
+		"total number of handled connections",
+		nil, nil)
+
+	requestsDesc = prometheus.NewDesc(
+		"nginx_total_requests",
+		"total number of client requests",
+		nil, nil)
+
+	readingDesc = prometheus.NewDesc(
+		"nginx_current_reading_connections",
+		"current number of connections where nginx is reading the request header",
+		nil, nil)
+
+	writingDesc = prometheus.NewDesc(
+		"nginx_current_writing_connections",
+		"current number of connections where nginx is writing the response back to the client",
+		nil, nil)
+
+	waitingDesc = prometheus.NewDesc(
+		"nginx_current_waiting_connections",
+		"current number of idle client connections waiting for a request",
+		nil, nil)
+)
+
+type (
+	scrapeRequest struct {
+		results chan<- prometheus.Metric
+		done    chan struct{}
+	}
+
+	namedProcessCollector struct {
+		scrapeChan chan scrapeRequest
+		*proc.Grouper
+		fs *proc.FS
+	}
+)
+
+func newProcessCollector(
+	children bool,
+	n common.MatchNamer) (*namedProcessCollector, error) {
+
+	fs, err := proc.NewFS("/proc")
+	if err != nil {
+		return nil, err
+	}
+	p := &namedProcessCollector{
+		scrapeChan: make(chan scrapeRequest),
+		Grouper:    proc.NewGrouper(children, n),
+		fs:         fs,
+	}
+	_, err = p.Update(p.fs.AllProcs())
+	if err != nil {
+		return nil, err
+	}
+
+	go p.start()
+
+	return p, nil
+}
+
+// Describe implements prometheus.Collector.
+func (p *namedProcessCollector) Describe(ch chan<- *prometheus.Desc) {
+	ch <- cpuSecsDesc
+	ch <- numprocsDesc
+	ch <- readBytesDesc
+	ch <- writeBytesDesc
+	ch <- memResidentbytesDesc
+	ch <- memVirtualbytesDesc
+	ch <- startTimeDesc
+}
+
+// Collect implements prometheus.Collector.
+func (p *namedProcessCollector) Collect(ch chan<- prometheus.Metric) {
+	req := scrapeRequest{results: ch, done: make(chan struct{})}
+	p.scrapeChan <- req
+	<-req.done
+}
+
+func (p *namedProcessCollector) start() {
+	for req := range p.scrapeChan {
+		ch := req.results
+		p.scrape(ch)
+		req.done <- struct{}{}
+	}
+}
+
+func (p *namedProcessCollector) scrape(ch chan<- prometheus.Metric) {
+	s, err := getNginxStatus()
+	if err != nil {
+		glog.Warningf("unexpected error obtaining nginx status info: %v", err)
+		return
+	}
+
+	ch <- prometheus.MustNewConstMetric(activeDesc,
+		prometheus.GaugeValue, float64(s.Active))
+	ch <- prometheus.MustNewConstMetric(acceptedDesc,
+		prometheus.GaugeValue, float64(s.Accepted))
+	ch <- prometheus.MustNewConstMetric(handledDesc,
+		prometheus.GaugeValue, float64(s.Handled))
+	ch <- prometheus.MustNewConstMetric(requestsDesc,
+		prometheus.GaugeValue, float64(s.Requests))
+	ch <- prometheus.MustNewConstMetric(readingDesc,
+		prometheus.GaugeValue, float64(s.Reading))
+	ch <- prometheus.MustNewConstMetric(writingDesc,
+		prometheus.GaugeValue, float64(s.Writing))
+	ch <- prometheus.MustNewConstMetric(waitingDesc,
+		prometheus.GaugeValue, float64(s.Waiting))
+
+	_, err = p.Update(p.fs.AllProcs())
+	if err != nil {
+		glog.Warningf("unexpected error obtaining nginx process info: %v", err)
+		return
+	}
+
+	for gname, gcounts := range p.Groups() {
+		glog.Infof("%v", gname)
+		glog.Infof("%v", gcounts)
+		ch <- prometheus.MustNewConstMetric(numprocsDesc,
+			prometheus.GaugeValue, float64(gcounts.Procs))
+		ch <- prometheus.MustNewConstMetric(memResidentbytesDesc,
+			prometheus.GaugeValue, float64(gcounts.Memresident))
+		ch <- prometheus.MustNewConstMetric(memVirtualbytesDesc,
+			prometheus.GaugeValue, float64(gcounts.Memvirtual))
+		ch <- prometheus.MustNewConstMetric(startTimeDesc,
+			prometheus.GaugeValue, float64(gcounts.OldestStartTime.Unix()))
+		ch <- prometheus.MustNewConstMetric(cpuSecsDesc,
+			prometheus.CounterValue, gcounts.Cpu)
+		ch <- prometheus.MustNewConstMetric(readBytesDesc,
+			prometheus.CounterValue, float64(gcounts.ReadBytes))
+		ch <- prometheus.MustNewConstMetric(writeBytesDesc,
+			prometheus.CounterValue, float64(gcounts.WriteBytes))
+	}
+}

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

@@ -18,24 +18,30 @@ package main
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"io/ioutil"
+	"net"
 	"net/http"
 	"os"
 	"os/exec"
+	"syscall"
+	"time"
 
 	"github.com/golang/glog"
-
 	"k8s.io/kubernetes/pkg/api"
 
-	"k8s.io/ingress/core/pkg/ingress"
-	"k8s.io/ingress/core/pkg/ingress/defaults"
-
-	"errors"
-
 	"k8s.io/ingress/controllers/nginx/pkg/config"
 	ngx_template "k8s.io/ingress/controllers/nginx/pkg/template"
 	"k8s.io/ingress/controllers/nginx/pkg/version"
+	"k8s.io/ingress/core/pkg/ingress"
+	"k8s.io/ingress/core/pkg/ingress/defaults"
+)
+
+const (
+	ngxHealthPort = 18080
+	ngxHealthPath = "/healthz"
+	ngxStatusPath = "/internal_nginx_status"
 )
 
 var (
@@ -78,6 +84,7 @@ Error loading new template : %v
 	}
 
 	n.t = ngxTpl
+
 	go n.Start()
 
 	return n
@@ -93,15 +100,56 @@ type NGINXController struct {
 // Start start a new NGINX master process running in foreground.
 func (n NGINXController) Start() {
 	glog.Info("starting NGINX process...")
+
+	done := make(chan error, 1)
 	cmd := exec.Command(n.binary, "-c", cfgPath)
+	n.start(cmd, done)
+
+	// if the nginx master process dies the workers continue to process requests,
+	// passing checks but in case of updates in ingress no updates will be
+	// reflected in the nginx configuration which can lead to confusion and report
+	// issues because of this behavior.
+	// To avoid this issue we restart nginx in case of errors.
+	for {
+		err := <-done
+		if exitError, ok := err.(*exec.ExitError); ok {
+			waitStatus := exitError.Sys().(syscall.WaitStatus)
+			glog.Warningf(`
+-------------------------------------------------------------------------------
+NGINX master process died (%v): %v
+-------------------------------------------------------------------------------
+`, waitStatus.ExitStatus(), err)
+		}
+		cmd.Process.Release()
+		cmd = exec.Command(n.binary, "-c", cfgPath)
+		// we wait until the workers are killed
+		for {
+			conn, err := net.DialTimeout("tcp", "127.0.0.1:80", 1*time.Second)
+			if err == nil {
+				conn.Close()
+				break
+			}
+			time.Sleep(1 * time.Second)
+		}
+		// start a new nginx master process
+		n.start(cmd, done)
+	}
+}
+
+func (n *NGINXController) start(cmd *exec.Cmd, done chan error) {
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
 	if err := cmd.Start(); err != nil {
 		glog.Fatalf("nginx error: %v", err)
+		done <- err
+		return
 	}
-	if err := cmd.Wait(); err != nil {
-		glog.Errorf("nginx error: %v", err)
-	}
+
+	n.setupMonitor(cmd.Args)
+
+	go func() {
+		done <- cmd.Wait()
+	}()
 }
 
 // Reload checks if the running configuration file is different
@@ -260,7 +308,7 @@ func (n NGINXController) Name() string {
 
 // Check returns if the nginx healthz endpoint is returning ok (status code 200)
 func (n NGINXController) Check(_ *http.Request) error {
-	res, err := http.Get("http://127.0.0.1:18080/healthz")
+	res, err := http.Get(fmt.Sprintf("http://localhost:%v%v", ngxHealthPort, ngxHealthPath))
 	if err != nil {
 		return err
 	}

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
+}

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

@@ -0,0 +1,70 @@
+/*
+Copyright 2015 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 (
+	"reflect"
+	"testing"
+)
+
+func TestParseStatus(t *testing.T) {
+	tests := []struct {
+		in  string
+		out *nginxStatus
+	}{
+		{`Active connections: 43
+server accepts handled requests
+ 7368 7368 10993
+Reading: 0 Writing: 5 Waiting: 38`,
+			&nginxStatus{43, 7368, 7368, 10993, 0, 5, 38},
+		},
+		{`Active connections: 0
+server accepts handled requests
+ 1 7 0
+Reading: A Writing: B Waiting: 38`,
+			&nginxStatus{0, 1, 7, 0, 0, 0, 38},
+		},
+	}
+
+	for _, test := range tests {
+		r := parse(test.in)
+		if !reflect.DeepEqual(r, test.out) {
+			t.Fatalf("expected %v but returned  %v", test.out, r)
+		}
+	}
+}
+
+func TestToint(t *testing.T) {
+	tests := []struct {
+		in  []string
+		pos int
+		exp int
+	}{
+		{[]string{}, 0, 0},
+		{[]string{}, 1, 0},
+		{[]string{"A"}, 0, 0},
+		{[]string{"1"}, 0, 1},
+		{[]string{"a", "2"}, 1, 2},
+	}
+
+	for _, test := range tests {
+		v := toInt(test.in, test.pos)
+		if v != test.exp {
+			t.Fatalf("expected %v but returned  %v", test.exp, v)
+		}
+	}
+}

controllers/nginx/rootfs/etc/nginx/template/nginx.tmpl

@@ -349,6 +349,17 @@ http {
             {{ end }}
         }
 
+        # this location is used to extract nginx metrics
+        # using prometheus.
+        # TODO: enable extraction for vts module.
+        location /internal_nginx_status {
+            allow 127.0.0.1;
+            deny all;
+
+            access_log off;
+            stub_status on;
+        }
+
         location / {
             set $proxy_upstream_name "upstream-default-backend";
             proxy_pass             http://upstream-default-backend;

core/pkg/ingress/controller/controller.go

@@ -140,7 +140,7 @@ func newIngressController(config *Configuration) *GenericController {
 
 	eventBroadcaster := record.NewBroadcaster()
 	eventBroadcaster.StartLogging(glog.Infof)
-	eventBroadcaster.StartRecordingToSink(unversionedcore.EventSinkImpl{
+	eventBroadcaster.StartRecordingToSink(&unversionedcore.EventSinkImpl{
 		Interface: config.Client.Core().Events(config.Namespace),
 	})
 

core/pkg/ingress/controller/launch.go

@@ -11,9 +11,9 @@ import (
 	"time"
 
 	"github.com/golang/glog"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/spf13/pflag"
 
-	"github.com/prometheus/client_golang/prometheus"
 	"k8s.io/kubernetes/pkg/api"
 	clientset "k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset"
 	"k8s.io/kubernetes/pkg/client/restclient"
@@ -161,7 +161,7 @@ func registerHandlers(enableProfiling bool, port int, ic *GenericController) {
 		ic.cfg.Backend,
 	)
 
-	mux.Handle("/metrics", prometheus.Handler())
+	mux.Handle("/metrics", promhttp.Handler())
 
 	mux.HandleFunc("/build", func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusOK)

core/pkg/ingress/controller/metrics.go

@@ -16,7 +16,9 @@ limitations under the License.
 
 package controller
 
-import "github.com/prometheus/client_golang/prometheus"
+import (
+	"github.com/prometheus/client_golang/prometheus"
+)
 
 const (
 	ns          = "ingress_controller"
@@ -27,9 +29,6 @@ const (
 func init() {
 	prometheus.MustRegister(reloadOperation)
 	prometheus.MustRegister(reloadOperationErrors)
-
-	reloadOperationErrors.WithLabelValues(reloadLabel).Set(0)
-	reloadOperation.WithLabelValues(reloadLabel).Set(0)
 }
 
 var (