Expose gRPC prometheus metrics

Author: laozc

cmd/csi-proxy/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"flag"
+	"net/http"
 
 	diskapi "github.com/kubernetes-csi/csi-proxy/pkg/os/disk"
 	filesystemapi "github.com/kubernetes-csi/csi-proxy/pkg/os/filesystem"
@@ -19,6 +20,7 @@ import (
 	volumesrv "github.com/kubernetes-csi/csi-proxy/pkg/server/volume"
 	"golang.org/x/sys/windows"
 	"golang.org/x/sys/windows/svc"
+	"k8s.io/component-base/metrics/legacyregistry"
 	"k8s.io/klog/v2"
 )
 
@@ -34,11 +36,12 @@ func (i *workingDirFlags) Set(value string) error {
 }
 
 var (
-	kubeletPath    = flag.String("kubelet-path", `C:\var\lib\kubelet`, "Prefix path of the kubelet directory in the host file system")
-	windowsSvc     = flag.Bool("windows-service", false, "Configure as a Windows Service")
-	requirePrivacy = flag.Bool("require-privacy", true, "If true, New-SmbGlobalMapping will be called with -RequirePrivacy $true")
-	service        *handler
-	workingDirs    workingDirFlags
+	kubeletPath     = flag.String("kubelet-path", `C:\var\lib\kubelet`, "Prefix path of the kubelet directory in the host file system")
+	windowsSvc      = flag.Bool("windows-service", false, "Configure as a Windows Service")
+	requirePrivacy  = flag.Bool("require-privacy", true, "If true, New-SmbGlobalMapping will be called with -RequirePrivacy $true")
+	metricsBindAddr = flag.String("metrics-bind-address", "", "The address the metric endpoint binds to. Defaults to empty in which case metrics are disabled")
+	service         *handler
+	workingDirs     workingDirFlags
 )
 
 type handler struct {
@@ -68,7 +71,18 @@ func main() {
 	if err != nil {
 		panic(err)
 	}
-	s := server.NewServer(apiGroups...)
+
+	enableMetrics := *metricsBindAddr != ""
+	if enableMetrics {
+		go func() error {
+			m := http.NewServeMux()
+			// Create HTTP handler for Prometheus metrics.
+			m.Handle("/metrics", legacyregistry.Handler())
+
+			return http.ListenAndServe(*metricsBindAddr, m)
+		}()
+	}
+	s := server.NewServer(enableMetrics, apiGroups...)
 
 	if err := s.Start(nil); err != nil {
 		panic(err)

go.mod

@@ -10,31 +10,46 @@ toolchain go1.22.3
 require (
 	github.com/Microsoft/go-winio v0.6.2
 	github.com/google/go-cmp v0.6.0
+	github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus v1.0.1
 	github.com/iancoleman/strcase v0.3.0
 	github.com/kubernetes-csi/csi-proxy/client v1.1.3
 	github.com/pkg/errors v0.9.1
+	github.com/prometheus/client_golang v1.20.5
 	github.com/sergi/go-diff v1.3.1
 	github.com/spf13/pflag v1.0.5
 	github.com/stretchr/testify v1.10.0
 	golang.org/x/sys v0.28.0
 	google.golang.org/grpc v1.69.2
 	google.golang.org/protobuf v1.36.0
+	k8s.io/component-base v0.28.4
 	k8s.io/gengo v0.0.0-20240911193312-2b36238f13e9
 	k8s.io/klog/v2 v2.130.1
 )
 
 require (
-	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/blang/semver/v4 v4.0.0 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
 	github.com/go-logr/logr v1.4.2 // indirect
 	github.com/golang/protobuf v1.5.4 // indirect
-	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/grpc-ecosystem/go-grpc-middleware/v2 v2.1.0 // indirect
+	github.com/klauspost/compress v1.17.9 // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
+	github.com/prometheus/client_model v0.6.1 // indirect
+	github.com/prometheus/common v0.55.0 // indirect
+	github.com/prometheus/procfs v0.15.1 // indirect
+	github.com/rogpeppe/go-internal v1.13.1 // indirect
+	go.opentelemetry.io/otel v1.33.0 // indirect
 	golang.org/x/mod v0.22.0 // indirect
 	golang.org/x/net v0.33.0 // indirect
 	golang.org/x/sync v0.10.0 // indirect
 	golang.org/x/text v0.21.0 // indirect
 	golang.org/x/tools v0.28.0 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20241216192217-9240e9c98484 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
+	k8s.io/apimachinery v0.28.4 // indirect
 	k8s.io/klog v1.0.0 // indirect
 )
 

go.sum

@@ -3,12 +3,19 @@ github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03
 github.com/Microsoft/go-winio v0.4.16/go.mod h1:XB6nPKklQyQ7GC9LdcBEcBl8PF76WugXOPRXwdLnMv0=
 github.com/Microsoft/go-winio v0.6.2 h1:F2VQgta7ecxGYO8k3ZZz3RS8fVIXVxONVUPlNERoyfY=
 github.com/Microsoft/go-winio v0.6.2/go.mod h1:yd8OoFMLzJbo9gZq8j5qaps8bJ9aShtEA8Ipt1oGCvU=
+github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
+github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
+github.com/blang/semver/v4 v4.0.0 h1:1PFHFE6yCCTv8C1TeyNNarDzntLi7wMI5i/pzqYIsAM=
+github.com/blang/semver/v4 v4.0.0/go.mod h1:IbckMUScFkM3pff0VJDNKRiT6TG/YpiHIM2yvyW5YoQ=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
+github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
+github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/cncf/udpa/go v0.0.0-20201120205902-5459f2c99403/go.mod h1:WmhPx2Nbnhtbo57+VJT5O0JRkEi1Wbu0z5j0R8u5Hbk=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
+github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 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 v0.9.9-0.20210217033140-668b12f5399d/go.mod h1:cXg6YxExXjJnVBQHBLXeUAgxn2UodCpnH306RInaBQk=
@@ -42,21 +49,44 @@ github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeN
 github.com/google/uuid v1.1.2/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus v1.0.1 h1:qnpSQwGEnkcRpTqNOIR6bJbR0gAorgP9CSALpRcKoAA=
+github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus v1.0.1/go.mod h1:lXGCsh6c22WGtjr+qGHj1otzZpV/1kwTMAqkwZsnWRU=
+github.com/grpc-ecosystem/go-grpc-middleware/v2 v2.1.0 h1:pRhl55Yx1eC7BZ1N+BBWwnKaMyD8uC+34TLdndZMAKk=
+github.com/grpc-ecosystem/go-grpc-middleware/v2 v2.1.0/go.mod h1:XKMd7iuf/RGPSMJ/U4HP0zS2Z9Fh8Ps9a+6X26m/tmI=
 github.com/iancoleman/strcase v0.3.0 h1:nTXanmYxhfFAMjZL34Ov6gkzEsSJZ5DbhxWjvSASxEI=
 github.com/iancoleman/strcase v0.3.0/go.mod h1:iwCmte+B7n89clKwxIoIXy/HfoL7AsD47ZCWhYzw7ho=
+github.com/klauspost/compress v1.17.9 h1:6KIumPrER1LHsvBVuDa0r5xaG0Es51mhhB9BQB2qeMA=
+github.com/klauspost/compress v1.17.9/go.mod h1:Di0epgTjJY877eYKx5yC51cX2A2Vl2ibi7bDH9ttBbw=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
-github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
-github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
+github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
 github.com/mauriciopoppe/gengo v0.0.0-20210525224835-9c78f58f3486 h1:+l047vEi0SyAzdVToIaAcfoY5DwwGW+OyqTdH/P3TTg=
 github.com/mauriciopoppe/gengo v0.0.0-20210525224835-9c78f58f3486/go.mod h1:xXv3T4UXTLta31wMhVezwVkc26OLei4hMbLeBJbPmxc=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
-github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
+github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/prometheus/client_golang v1.20.5 h1:cxppBPuYhUnsO6yo/aoRol4L7q7UFfdm+bR9r+8l63Y=
+github.com/prometheus/client_golang v1.20.5/go.mod h1:PIEt8X02hGcP8JWbeHyeZ53Y/jReSnHgO035n//V5WE=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
+github.com/prometheus/client_model v0.6.1 h1:ZKSh/rekM+n3CeS952MLRAdFwIKqeY8b62p8ais2e9E=
+github.com/prometheus/client_model v0.6.1/go.mod h1:OrxVMOVHjw3lKMa8+x6HeMGkHMQyHDk9E3jmP2AmGiY=
+github.com/prometheus/common v0.55.0 h1:KEi6DK7lXW/m7Ig5i47x0vRzuBsHuvJdi5ee6Y3G1dc=
+github.com/prometheus/common v0.55.0/go.mod h1:2SECS4xJG1kd8XF9IcM1gMX6510RAEL65zxzNImwdc8=
+github.com/prometheus/procfs v0.15.1 h1:YagwOFzUgYfKKHX6Dr+sHT7km/hxC76UB0learggepc=
+github.com/prometheus/procfs v0.15.1/go.mod h1:fB45yRUv8NstnjriLhBQLuOUt+WW4BsoGhij/e3PBqk=
+github.com/rogpeppe/go-internal v1.13.1 h1:KvO1DLK/DRN07sQ1LQKScxyZJuNnedQ5/wKSR38lUII=
+github.com/rogpeppe/go-internal v1.13.1/go.mod h1:uMEvuHeurkdAXX61udpOXGD/AzZDWNMNyH2VO9fmH0o=
 github.com/sergi/go-diff v1.3.1 h1:xkr+Oxo4BOQKmkn/B9eMK0g5Kg/983T9DqqPHwYqD+8=
 github.com/sergi/go-diff v1.3.1/go.mod h1:aMJSSKb2lpPvRNec0+w3fl7LP9IOFzdc9Pa4NFbPK1I=
 github.com/sirupsen/logrus v1.4.1/go.mod h1:ni0Sbl8bgC9z8RoU9G6nDWqqs/fq4eDPysMBDgk/93Q=
@@ -69,16 +99,18 @@ github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81P
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
-go.opentelemetry.io/otel v1.31.0 h1:NsJcKPIW0D0H3NgzPDHmo0WW6SptzPdqg/L1zsIm2hY=
-go.opentelemetry.io/otel v1.31.0/go.mod h1:O0C14Yl9FgkjqcCZAsE053C13OaddMYr/hz6clDkEJE=
-go.opentelemetry.io/otel/metric v1.31.0 h1:FSErL0ATQAmYHUIzSezZibnyVlft1ybhy4ozRPcF2fE=
-go.opentelemetry.io/otel/metric v1.31.0/go.mod h1:C3dEloVbLuYoX41KpmAhOqNriGbA+qqH6PQ5E5mUfnY=
+go.opentelemetry.io/auto/sdk v1.1.0 h1:cH53jehLUN6UFLY71z+NDOiNJqDdPRaXzTel0sJySYA=
+go.opentelemetry.io/auto/sdk v1.1.0/go.mod h1:3wSPjt5PWp2RhlCcmmOial7AvC4DQqZb7a7wCow3W8A=
+go.opentelemetry.io/otel v1.33.0 h1:/FerN9bax5LoK51X/sI0SVYrjSE0/yUL7DpxW4K3FWw=
+go.opentelemetry.io/otel v1.33.0/go.mod h1:SUUkR6csvUQl+yjReHu5uM3EtVV7MBm5FHKRlNx4I8I=
+go.opentelemetry.io/otel/metric v1.33.0 h1:r+JOocAyeRVXD8lZpjdQjzMadVZp2M4WmQ+5WtEnklQ=
+go.opentelemetry.io/otel/metric v1.33.0/go.mod h1:L9+Fyctbp6HFTddIxClbQkjtubW6O9QS3Ann/M82u6M=
 go.opentelemetry.io/otel/sdk v1.31.0 h1:xLY3abVHYZ5HSfOg3l2E5LUj2Cwva5Y7yGxnSW9H5Gk=
 go.opentelemetry.io/otel/sdk v1.31.0/go.mod h1:TfRbMdhvxIIr/B2N2LQW2S5v9m3gOQ/08KsbbO5BPT0=
 go.opentelemetry.io/otel/sdk/metric v1.31.0 h1:i9hxxLJF/9kkvfHppyLL55aW7iIJz4JjxTeYusH7zMc=
 go.opentelemetry.io/otel/sdk/metric v1.31.0/go.mod h1:CRInTMVvNhUKgSAMbKyTMxqOBC0zgyxzW55lZzX43Y8=
-go.opentelemetry.io/otel/trace v1.31.0 h1:ffjsj1aRouKewfr85U2aGagJ46+MvodynlQ1HYdmJys=
-go.opentelemetry.io/otel/trace v1.31.0/go.mod h1:TXZkRk7SM2ZQLtR6eoAWQFIHPvzQ06FJAsO1tJg480A=
+go.opentelemetry.io/otel/trace v1.33.0 h1:cCJuF7LRjUFso9LPnEAHJDB2pqzp+hbO8eu1qqW2d/s=
+go.opentelemetry.io/otel/trace v1.33.0/go.mod h1:uIcdVUZMpTAmz0tI1z04GoVSezK37CbGV4fr1f2nBck=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
@@ -140,15 +172,22 @@ google.golang.org/protobuf v1.25.0/go.mod h1:9JNX74DMeImyA3h4bdi1ymwjUzf21/xIlba
 google.golang.org/protobuf v1.36.0 h1:mjIs9gYtt56AzC4ZaffQuh88TZurBGhIJMBZGSxNerQ=
 google.golang.org/protobuf v1.36.0/go.mod h1:9fA7Ob0pmnwhb644+1+CVWFRbNajQ6iRojtC/QF5bRE=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
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 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
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 k8s.io/klog v1.0.0/go.mod h1:4Bi6QPql/J/LkTDqv7R/cd3hPo4k2DG6Ptcz060Ez5I=
 k8s.io/klog/v2 v2.130.1 h1:n9Xl7H1Xvksem4KFG4PYbdQCQxqc/tTUyrgXaOhHSzk=
 k8s.io/klog/v2 v2.130.1/go.mod h1:3Jpz1GvMt720eyJH1ckRHK1EDfpxISzJ7I9OYgaDtPE=
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+k8s.io/utils v0.0.0-20230406110748-d93618cff8a2/go.mod h1:OLgZIPagt7ERELqWJFomSt595RzquPNLL48iOWgYOg0=

integrationtests/utils.go

@@ -27,7 +27,7 @@ import (
 
 // startServer starts the proxy's GRPC servers, and returns a function to shut them down when done with testing
 func startServer(t *testing.T, apiGroups ...srvtypes.APIGroup) func() {
-	s := server.NewServer(apiGroups...)
+	s := server.NewServer(nil, apiGroups...)
 
 	listeningChan := make(chan interface{})
 	go func() {

pkg/server/metrics/metrics.go

@@ -0,0 +1,50 @@
+package metrics
+
+import (
+	"sync"
+
+	grpcprom "github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus"
+	"github.com/prometheus/client_golang/prometheus"
+	"google.golang.org/grpc"
+	"k8s.io/component-base/metrics/legacyregistry"
+)
+
+var (
+	// metricsList is a list of all raw metrics that should be registered always, regardless of any feature gate's value.
+	metricsList       []prometheus.Collector
+	grpcServerMetrics *grpcprom.ServerMetrics
+	registerMetrics   sync.Once
+)
+
+func initMetrics() {
+	grpcServerMetrics = grpcprom.NewServerMetrics(
+		grpcprom.WithServerHandlingTimeHistogram(
+			grpcprom.WithHistogramBuckets([]float64{0.001, 0.01, 0.1, 0.3, 0.6, 1, 3, 6, 9, 20, 30, 60, 90, 120}),
+		),
+	)
+
+	metricsList = []prometheus.Collector{
+		grpcServerMetrics,
+	}
+}
+
+// Register registers a list of metrics.
+func Register() {
+	registerMetrics.Do(func() {
+		initMetrics()
+		for _, metric := range metricsList {
+			legacyregistry.RawMustRegister(metric)
+		}
+	})
+}
+
+func GRPCMetricsOptions() []grpc.ServerOption {
+	return []grpc.ServerOption{
+		grpc.ChainUnaryInterceptor(
+			grpcServerMetrics.UnaryServerInterceptor(),
+		),
+		grpc.ChainStreamInterceptor(
+			grpcServerMetrics.StreamServerInterceptor(),
+		),
+	}
+}

pkg/server/server.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/Microsoft/go-winio"
 	"github.com/kubernetes-csi/csi-proxy/client"
+	"github.com/kubernetes-csi/csi-proxy/pkg/server/metrics"
 	srvtypes "github.com/kubernetes-csi/csi-proxy/pkg/server/types"
 	"github.com/pkg/errors"
 	"google.golang.org/grpc"
@@ -19,18 +20,24 @@ type Server struct {
 	started       bool
 	mutex         *sync.Mutex
 	grpcServers   []*grpc.Server
+	exposeMetrics bool
 }
 
 // NewServer creates a new Server for the given API groups.
-func NewServer(apiGroups ...srvtypes.APIGroup) *Server {
+func NewServer(enableMetrics bool, apiGroups ...srvtypes.APIGroup) *Server {
 	versionedAPIs := make([]*srvtypes.VersionedAPI, 0, len(apiGroups))
 	for _, apiGroup := range apiGroups {
 		versionedAPIs = append(versionedAPIs, apiGroup.VersionedAPIs()...)
 	}
 
+	if enableMetrics {
+		metrics.Register()
+	}
+
 	return &Server{
 		versionedAPIs: versionedAPIs,
 		mutex:         &sync.Mutex{},
+		exposeMetrics: enableMetrics,
 	}
 }
 
@@ -108,7 +115,11 @@ func (s *Server) createAndStartGRPCServers(listeners []net.Listener) chan *versi
 	s.grpcServers = make([]*grpc.Server, len(s.versionedAPIs))
 
 	for i, versionedAPI := range s.versionedAPIs {
-		grpcServer := grpc.NewServer()
+		var opts []grpc.ServerOption
+		if s.exposeMetrics {
+			opts = append(opts, metrics.GRPCMetricsOptions()...)
+		}
+		grpcServer := grpc.NewServer(opts...)
 		s.grpcServers[i] = grpcServer
 
 		versionedAPI.Registrant(grpcServer)