[ws-scheduler] Add Prometheus metrics to scaler

components/ee/ws-scheduler/cmd/run.go

@@ -58,6 +58,8 @@ var runCmd = &cobra.Command{
 			log.Info("ws-scheduler shut down")
 		}()
 
+		reg := prometheus.NewRegistry()
+
 		if config.Scaler.Enabled {
 			controller, err := scaler.NewController(config.Scaler.Controller)
 			if err != nil {
@@ -67,14 +69,17 @@ var runCmd = &cobra.Command{
 			if err != nil {
 				log.WithError(err).Fatal("cannot create scaler driver")
 			}
+			err = driver.RegisterMetrics(prometheus.WrapRegistererWithPrefix("gitpod_ws_scaler_", reg))
+			if err != nil {
+				log.WithError(err).Fatal("cannot register metrics")
+			}
+
 			go driver.Run()
 			defer driver.Stop()
-
 			log.WithField("controller", config.Scaler.Controller.Kind).Info("started scaler")
 		}
 
 		if config.Prometheus.Addr != "" {
-			reg := prometheus.NewRegistry()
 			reg.MustRegister(
 				prometheus.NewGoCollector(),
 				prometheus.NewProcessCollector(prometheus.ProcessCollectorOpts{}),

components/ee/ws-scheduler/go.mod

@@ -11,9 +11,9 @@ require (
 	github.com/go-ozzo/ozzo-validation v3.5.0+incompatible
 	github.com/golang/groupcache v0.0.0-20191027212112-611e8accdfc9 // indirect
 	github.com/golang/mock v1.4.3
-	github.com/golang/protobuf v1.3.5
+	github.com/golang/protobuf v1.4.2
-	github.com/google/go-cmp v0.4.0
+	github.com/google/go-cmp v0.5.0
-	github.com/google/uuid v1.1.1
+	github.com/google/uuid v1.1.2
 	github.com/googleapis/gnostic v0.3.1 // indirect
 	github.com/hashicorp/golang-lru v0.5.3 // indirect
 	github.com/opentracing/opentracing-go v1.1.0
@@ -23,7 +23,7 @@ require (
 	golang.org/x/crypto v0.0.0-20191112222119-e1110fd1c708 // indirect
 	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1
 	google.golang.org/appengine v1.6.5 // indirect
-	google.golang.org/grpc v1.29.1
+	google.golang.org/grpc v1.34.0
 	k8s.io/api v0.0.0
 	k8s.io/apimachinery v0.0.0
 	k8s.io/client-go v0.0.0

components/ee/ws-scheduler/go.sum

@@ -55,6 +55,7 @@ github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDk
 github.com/cloudflare/cfssl v0.0.0-20180726162950-56268a613adf/go.mod h1:yMWuSON2oQp+43nFtAV/uvKQIFpSPerB57DCt9t8sSA=
 github.com/clusterhq/flocker-go v0.0.0-20160920122132-2b8b7259d313/go.mod h1:P1wt9Z3DP8O6W3rvwCt0REIlshg1InHImaLW0t3ObY0=
 github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f/go.mod h1:M8M6+tZqaGXZJjfX53e64911xZQV5JYwmTeXPW+k8Sc=
+github.com/cncf/udpa/go v0.0.0-20200629203442-efcf912fb354/go.mod h1:WmhPx2Nbnhtbo57+VJT5O0JRkEi1Wbu0z5j0R8u5Hbk=
 github.com/codahale/hdrhistogram v0.0.0-20161010025455-3a0bb77429bd h1:qMd81Ts1T2OTKmB4acZcyKaMtRnY5Y44NuXGX2GFJ1w=
 github.com/codahale/hdrhistogram v0.0.0-20161010025455-3a0bb77429bd/go.mod h1:sE/e/2PUdi/liOCUjSTXgM1o87ZssimdTWN964YiIeI=
 github.com/codedellemc/goscaleio v0.0.0-20170830184815-20e2ce2cf885/go.mod h1:JIHmDHNZO4tmA3y3RHp6+Gap6kFsNf55W9Pn/3YS9IY=
@@ -95,7 +96,9 @@ github.com/docopt/docopt-go v0.0.0-20180111231733-ee0de3bc6815/go.mod h1:WwZ+bS3
 github.com/elazarl/goproxy v0.0.0-20170405201442-c4fc26588b6e/go.mod h1:/Zj4wYkgs4iZTTu3o/KG3Itv/qCCa8VVMlb3i9OVuzc=
 github.com/emicklei/go-restful v0.0.0-20170410110728-ff4f55a20633/go.mod h1:otzb+WCGbkyDHkqmQmT5YD2WR4BBwUdeQoFo8l/7tVs=
 github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
+github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1mIlRU8Am5FuJP05cCM98=
+github.com/envoyproxy/go-control-plane v0.9.7/go.mod h1:cwu0lG7PUMfa9snN8LXBig5ynNVH9qI8YYLbd1fK2po=
 github.com/envoyproxy/protoc-gen-validate v0.1.0/go.mod h1:iSmxcyjqTsJpI2R4NaDN7+kN2VEUnK/pcBlmesArF7c=
 github.com/euank/go-kmsg-parser v2.0.0+incompatible/go.mod h1:MhmAMZ8V4CYH4ybgdRwPr2TU5ThnS43puaKEMpja1uw=
 github.com/evanphx/json-patch v0.0.0-20190203023257-5858425f7550 h1:mV9jbLoSW/8m4VK16ZkHTozJa8sesK5u5kTMFysTYac=
@@ -161,6 +164,13 @@ github.com/golang/protobuf v1.3.3 h1:gyjaxf+svBWX08ZjK86iN9geUJF0H6gp2IRKX6Nf6/I
 github.com/golang/protobuf v1.3.3/go.mod h1:vzj43D7+SQXF/4pzW/hwtAqwc6iTitCiVSaWz5lYuqw=
 github.com/golang/protobuf v1.3.5 h1:F768QJ1E9tib+q5Sc8MkdJi1RxLTbRcTf8LJV56aRls=
 github.com/golang/protobuf v1.3.5/go.mod h1:6O5/vntMXwX2lRkT1hjjk0nAC1IDOTvTlVgjlRvqsdk=
+github.com/golang/protobuf v1.4.0-rc.1/go.mod h1:ceaxUfeHdC40wWswd/P6IGgMaK3YpKi5j83Wpe3EHw8=
+github.com/golang/protobuf v1.4.0-rc.1.0.20200221234624-67d41d38c208/go.mod h1:xKAWHe0F5eneWXFV3EuXVDTCmh+JuBKY0li0aMyXATA=
+github.com/golang/protobuf v1.4.0-rc.2/go.mod h1:LlEzMj4AhA7rCAGe4KMBDvJI+AwstrUpVNzEA03Pprs=
+github.com/golang/protobuf v1.4.0-rc.4.0.20200313231945-b860323f09d0/go.mod h1:WU3c8KckQ9AFe+yFwt9sWVRKCVIyN9cPHBJSNnbL67w=
+github.com/golang/protobuf v1.4.0/go.mod h1:jodUvKwWbYaEsadDk5Fwe5c77LiNKVO9IDvqG2KuDX0=
+github.com/golang/protobuf v1.4.1/go.mod h1:U8fpvMrcmy5pZrNK1lt4xCsGvpyWQ/VVv6QDs8UjoX8=
+github.com/golang/protobuf v1.4.2/go.mod h1:oDoupMAO8OvCJWAcko0GGGIgR6R6ocIYbsSw735rRwI=
 github.com/golangplus/bytes v0.0.0-20160111154220-45c989fe5450/go.mod h1:Bk6SMAONeMXrxql8uvOKuAZSu8aM5RUGv+1C6IJaEho=
 github.com/golangplus/fmt v0.0.0-20150411045040-2a5d6d7d2995/go.mod h1:lJgMEyOkYFkPcDKwRXegd+iM6E7matEszMG5HhwytU8=
 github.com/golangplus/testing v0.0.0-20180327235837-af21d9c3145e/go.mod h1:0AA//k/eakGydO4jKRoRL2j92ZKSzTgj9tclaCrvXHk=
@@ -172,8 +182,10 @@ github.com/google/cadvisor v0.33.2-0.20190411163913-9db8c7dee20a/go.mod h1:1nql6
 github.com/google/certificate-transparency-go v1.0.21/go.mod h1:QeJfpSbVSfYc7RgB3gJFj9cbuQMMchQxrWXz8Ruopmg=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
+github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/go-cmp v0.4.0 h1:xsAVV57WRhGj6kEIi8ReJzQlHHqcBYCElAvkovg3B/4=
 github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/gofuzz v0.0.0-20170612174753-24818f796faf h1:+RRA9JqSOZFfKrOeqr2z77+8R2RKyh8PG66dcu1V0ck=
 github.com/google/gofuzz v0.0.0-20170612174753-24818f796faf/go.mod h1:HP5RmnzzSNb993RKQDq4+1A4ia9nllfqcQFTQJedwGI=
 github.com/google/gofuzz v1.0.0 h1:A8PeW59pxE9IoFRqBp37U+mSNaQoZ46F1f0f863XSXw=
@@ -185,6 +197,7 @@ github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm4
 github.com/google/uuid v1.0.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/google/uuid v1.1.1 h1:Gkbcsh/GbpXz7lPftLA3P6TYMwjCLYm83jiFQZF/3gY=
 github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/google/uuid v1.1.2/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/googleapis/gax-go/v2 v2.0.4/go.mod h1:0Wqv26UfaUD9n4G6kQubkQ+KchISgw+vpHVxEJEs9eg=
 github.com/googleapis/gax-go/v2 v2.0.5/go.mod h1:DWXyrwAJ9X0FpwwEdw+IPEYBICEFu5mhpdKc/us6bOk=
 github.com/googleapis/gnostic v0.0.0-20170729233727-0c5108395e2d/go.mod h1:sJBsCZ4ayReDTBIg8b9dl28c5xFWyhBTVRp3pOg5EKY=
@@ -369,6 +382,7 @@ github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
+github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/syndtr/gocapability v0.0.0-20160928074757-e7cb7fa329f4/go.mod h1:hkRG7XYTFWNJGYcbNJQlaLq0fg1yr4J4t/NcTQtrfww=
 github.com/tmc/grpc-websocket-proxy v0.0.0-20170815181823-89b8d40f7ca8/go.mod h1:ncp9v5uamzpCO7NfCPTXjqaC+bZgJeR0sMTm6dMHP7U=
 github.com/uber-go/atomic v1.4.0 h1:yOuPqEq4ovnhEjpHmfFwsqBXDYbQeT6Nb0bwD6XnD5o=
@@ -543,6 +557,7 @@ google.golang.org/genproto v0.0.0-20190819201941-24fa4b261c55/go.mod h1:DMBHOl98
 google.golang.org/genproto v0.0.0-20190911173649-1774047e7e51/go.mod h1:IbNlFCBrqXvoKpeg0TB2l7cyZUmoaFKYIwrEpbDKLA8=
 google.golang.org/genproto v0.0.0-20191108220845-16a3f7862a1a h1:Ob5/580gVHBJZgXnff1cZDbG+xLtMVE5mDRTe+nIsX4=
 google.golang.org/genproto v0.0.0-20191108220845-16a3f7862a1a/go.mod h1:n3cpQtvxv34hfy77yVDNjmbRyujviMdxYliBSkLhpCc=
+google.golang.org/genproto v0.0.0-20200526211855-cb27e3aa2013/go.mod h1:NbSheEEYHJ7i3ixzK3sjbqSGDJWnxyFXZblF3eUsNvo=
 google.golang.org/grpc v1.13.0/go.mod h1:yo6s7OP7yaDglbqo1J04qKzAhqBH6lvTonzMVmEdcZw=
 google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
 google.golang.org/grpc v1.20.1/go.mod h1:10oTOabMzJvdu6/UiuZezV6QK5dSlG84ov/aaiqXj38=
@@ -550,8 +565,19 @@ google.golang.org/grpc v1.21.1 h1:j6XxA85m/6txkUCHvzlV5f+HBNl/1r5cZ2A/3IEFOO8=
 google.golang.org/grpc v1.21.1/go.mod h1:oYelfM1adQP15Ek0mdvEgi9Df8B9CZIaU1084ijfRaM=
 google.golang.org/grpc v1.23.0/go.mod h1:Y5yQAOtifL1yxbo5wqy6BxZv8vAUGQwXBOALyacEbxg=
 google.golang.org/grpc v1.25.1/go.mod h1:c3i+UQWmh7LiEpx4sFZnkU36qjEYZ0imhYfXVyQciAY=
+google.golang.org/grpc v1.27.0/go.mod h1:qbnxyOmOxrQa7FizSgH+ReBfzJrCY1pSN7KXBS8abTk=
 google.golang.org/grpc v1.29.1 h1:EC2SB8S04d2r73uptxphDSUG+kTKVgjRPF+N3xpxRB4=
 google.golang.org/grpc v1.29.1/go.mod h1:itym6AZVZYACWQqET3MqgPpjcuV5QH3BxFS3IjizoKk=
+google.golang.org/grpc v1.34.0/go.mod h1:WotjhfgOW/POjDeRt8vscBtXq+2VjORFy659qA51WJ8=
+google.golang.org/protobuf v0.0.0-20200109180630-ec00e32a8dfd/go.mod h1:DFci5gLYBciE7Vtevhsrf46CRTquxDuWsQurQQe4oz8=
+google.golang.org/protobuf v0.0.0-20200221191635-4d8936d0db64/go.mod h1:kwYJMbMJ01Woi6D6+Kah6886xMZcty6N08ah7+eCXa0=
+google.golang.org/protobuf v0.0.0-20200228230310-ab0ca4ff8a60/go.mod h1:cfTl7dwQJ+fmap5saPgwCLgHXTUD7jkjRqWcaiX5VyM=
+google.golang.org/protobuf v1.20.1-0.20200309200217-e05f789c0967/go.mod h1:A+miEFZTKqfCUM6K7xSMQL9OKL/b6hQv+e19PK+JZNE=
+google.golang.org/protobuf v1.21.0/go.mod h1:47Nbq4nVaFHyn7ilMalzfO3qCViNmqZ2kzikPIcrTAo=
+google.golang.org/protobuf v1.22.0/go.mod h1:EGpADcykh3NcUnDUJcl1+ZksZNG86OlYog2l/sGQquU=
+google.golang.org/protobuf v1.23.0/go.mod h1:EGpADcykh3NcUnDUJcl1+ZksZNG86OlYog2l/sGQquU=
+google.golang.org/protobuf v1.23.1-0.20200526195155-81db48ad09cc/go.mod h1:EGpADcykh3NcUnDUJcl1+ZksZNG86OlYog2l/sGQquU=
+google.golang.org/protobuf v1.25.0/go.mod h1:9JNX74DMeImyA3h4bdi1ymwjUzf21/xIlbajtzgsN7c=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

components/ee/ws-scheduler/pkg/scaler/driver.go

@@ -16,6 +16,7 @@ import (
 	"github.com/gitpod-io/gitpod/ws-manager/api"
 	"github.com/golang/protobuf/ptypes"
 	"github.com/google/uuid"
+	"github.com/prometheus/client_golang/prometheus"
 	"golang.org/x/xerrors"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
@@ -80,7 +81,8 @@ type WorkspaceManagerPrescaleDriver struct {
 
 	Controller Controller
 
-	time timer
+	time    timer
+	metrics *metrics
 
 	stop chan struct{}
 	once sync.Once
@@ -91,6 +93,12 @@ type workspaceStatus struct {
 	DeletionCandidates []string
 }
 
+// RegisterMetrics registers prometheus metrics for this driver
+func (wspd *WorkspaceManagerPrescaleDriver) RegisterMetrics(reg prometheus.Registerer) error {
+	wspd.metrics = newMetrics()
+	return wspd.metrics.Register(reg)
+}
+
 // Run runs the prescale driver until Stop() is called
 func (wspd *WorkspaceManagerPrescaleDriver) Run() {
 	ctx, cancel := context.WithCancel(context.Background())
@@ -141,6 +149,7 @@ func (wspd *WorkspaceManagerPrescaleDriver) Run() {
 			}
 			status.Count.Ghost += len(startingGhosts)
 			counts <- status.Count
+			wspd.metrics.OnGhostCountChange(status.Count.Ghost)
 			log.WithField("counts", status.Count).Debug("status update")
 		case <-houseKeeping:
 			for id, t1 := range startingGhosts {
@@ -179,6 +188,7 @@ func (wspd *WorkspaceManagerPrescaleDriver) Run() {
 			log.WithField("delta", d).Info("renewed ghost workspaces")
 		case setpoint = <-cchan:
 			// we've already set the new setpoint - wait for scheduleGhosts to act on it.
+			wspd.metrics.OnSetpointChange(setpoint)
 		case <-scheduleGhosts:
 			d := setpoint - status.Count.Ghost
 			if d == 0 {

components/ee/ws-scheduler/pkg/scaler/metrics.go

@@ -0,0 +1,59 @@
+// Copyright (c) 2020 TypeFox GmbH. All rights reserved.
+// Licensed under the Gitpod Enterprise Source Code License,
+// See License.enterprise.txt in the project root folder.
+
+package scaler
+
+import "github.com/prometheus/client_golang/prometheus"
+
+type metrics struct {
+	setpointGauge   prometheus.Gauge
+	ghostCountGauge prometheus.Gauge
+}
+
+func newMetrics() *metrics {
+	return &metrics{
+		setpointGauge: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: "driver_setpoint",
+			Help: "setpoint of the scaler driver",
+		}),
+		ghostCountGauge: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: "ghost_count",
+			Help: "current number of Ghost workspaces scaler is aware of",
+		}),
+	}
+}
+
+// Register registers all metrics scaler can export
+func (m *metrics) Register(reg prometheus.Registerer) error {
+	if m == nil {
+		return nil
+	}
+
+	collectors := []prometheus.Collector{
+		m.setpointGauge,
+		m.ghostCountGauge,
+	}
+	for _, c := range collectors {
+		err := reg.Register(c)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (m *metrics) OnSetpointChange(v int) {
+	if m == nil {
+		return
+	}
+	m.setpointGauge.Set(float64(v))
+}
+
+func (m *metrics) OnGhostCountChange(v int) {
+	if m == nil {
+		return
+	}
+	m.ghostCountGauge.Set(float64(v))
+}