stop using github.com/grpc-ecosystem/go-grpc-prometheus which has been archived since apr 18, 2023

go.mod

@@ -5,8 +5,8 @@ go 1.23.1
 require (
 	github.com/chainguard-dev/clog v1.7.0
 	github.com/google/go-cmp v0.7.0
+	github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus v1.1.0
 	github.com/grpc-ecosystem/go-grpc-middleware/v2 v2.3.2
-	github.com/grpc-ecosystem/go-grpc-prometheus v1.2.1-0.20210315223345-82c243799c99
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.1
 	github.com/kelseyhightower/envconfig v1.4.0
 	github.com/prometheus/client_golang v1.22.0

go.sum

@@ -1,11 +1,9 @@
-cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
 cloud.google.com/go/auth v0.16.2 h1:QvBAGFPLrDeoiNjyfVunhQ10HKNYuOwZ5noee0M5df4=
 cloud.google.com/go/auth v0.16.2/go.mod h1:sRBas2Y1fB1vZTdurouM0AzuYQBMZinrUYL8EufhtEA=
 cloud.google.com/go/auth/oauth2adapt v0.2.8 h1:keo8NaayQZ6wimpNSmW5OPc283g65QNIiLpZnkHRbnc=
 cloud.google.com/go/auth/oauth2adapt v0.2.8/go.mod h1:XQ9y31RkqZCcwJWNSx2Xvric3RrU88hAYYbjDWYDL+c=
 cloud.google.com/go/compute/metadata v0.7.0 h1:PBWF+iiAerVNe8UCHxdOt6eHLVc3ydFeOCw78U8ytSU=
 cloud.google.com/go/compute/metadata v0.7.0/go.mod h1:j5MvL9PprKL39t166CoB1uVHfQMs4tFQZZcKwksXUjo=
-github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
 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/cenkalti/backoff/v5 v5.0.2 h1:rIfFVxEf1QsI7E1ZHfp/B4DF/6QBAUhmgkxc0H7Zss8=
@@ -14,8 +12,6 @@ github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UF
 github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/chainguard-dev/clog v1.7.0 h1:guPznsK8vLHvzz1QJe2yU6MFeYaiSOFOQBYw4OXu+g8=
 github.com/chainguard-dev/clog v1.7.0/go.mod h1:4+WFhRMsGH79etYXY3plYdp+tCz/KCkU8fAr0HoaPvs=
-github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
-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/felixge/httpsnoop v1.0.4 h1:NFTV2Zj1bL4mc9sqWACXbQFVBBg2W3GPvqp8/ESS2Wg=
@@ -25,9 +21,6 @@ github.com/go-logr/logr v1.4.3 h1:CjnDlHq8ikf6E492q6eKboGOC0T8CDaOvkHCIg8idEI=
 github.com/go-logr/logr v1.4.3/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
 github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
 github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
-github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
-github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
-github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
 github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
 github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
@@ -40,39 +33,30 @@ github.com/googleapis/enterprise-certificate-proxy v0.3.6 h1:GW/XbdyBFQ8Qe+YAmFU
 github.com/googleapis/enterprise-certificate-proxy v0.3.6/go.mod h1:MkHOF77EYAE7qfSuSS9PU6g4Nt4e11cnsDUowfwewLA=
 github.com/googleapis/gax-go/v2 v2.14.2 h1:eBLnkZ9635krYIPD+ag1USrOAI0Nr0QYF3+/3GqO0k0=
 github.com/googleapis/gax-go/v2 v2.14.2/go.mod h1:ON64QhlJkhVtSqp4v1uaK92VyZ2gmvDQsweuyLV+8+w=
+github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus v1.1.0 h1:QGLs/O40yoNK9vmy4rhUGBVyMf1lISBGtXRpsu/Qu/o=
+github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus v1.1.0/go.mod h1:hM2alZsMUni80N33RBe6J0e423LB+odMj7d3EMP9l20=
 github.com/grpc-ecosystem/go-grpc-middleware/v2 v2.3.2 h1:sGm2vDRFUrQJO/Veii4h4zG2vvqG6uWNkBHSTqXOZk0=
 github.com/grpc-ecosystem/go-grpc-middleware/v2 v2.3.2/go.mod h1:wd1YpapPLivG6nQgbf7ZkG1hhSOXDhhn4MLTknx2aAc=
-github.com/grpc-ecosystem/go-grpc-prometheus v1.2.1-0.20210315223345-82c243799c99 h1:JYghRBlGCZyCF2wNUJ8W0cwaQdtpcssJ4CgC406g+WU=
-github.com/grpc-ecosystem/go-grpc-prometheus v1.2.1-0.20210315223345-82c243799c99/go.mod h1:3bDW6wMZJB7tiONtC/1Xpicra6Wp5GgbTbQWCbI5fkc=
 github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.1 h1:X5VWvz21y3gzm9Nw/kaUeku/1+uBhcekkmy4IkffJww=
 github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.1/go.mod h1:Zanoh4+gvIgluNqcfMVTJueD4wSS5hT7zTt4Mrutd90=
 github.com/kelseyhightower/envconfig v1.4.0 h1:Im6hONhd3pLkfDFsbRgu68RDNkGF1r3dvMUtDTo2cv8=
 github.com/kelseyhightower/envconfig v1.4.0/go.mod h1:cccZRl6mQpaq41TPp5QxidR+Sa3axMbJDNb//FQX6Gg=
-github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/klauspost/compress v1.18.0 h1:c/Cqfb0r+Yi+JtIEq73FWXVkRonBlf0CRNYc8Zttxdo=
 github.com/klauspost/compress v1.18.0/go.mod h1:2Pp+KzxcywXVXMr50+X0Q/Lsb43OQHYWRCY2AiWywWQ=
 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/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
 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/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/prometheus/client_golang v0.9.2/go.mod h1:OsXs2jCmiKlQ1lTBmv21f2mNfw4xf/QclQDMrYNZzcM=
 github.com/prometheus/client_golang v1.22.0 h1:rb93p9lokFEsctTys46VnV1kLCDpVZ0a/Y92Vm0Zc6Q=
 github.com/prometheus/client_golang v1.22.0/go.mod h1:R7ljNsLXhuQXYZYtw6GAE9AZg8Y7vEW5scdCXrWRXC0=
-github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
-github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90/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 v0.0.0-20181126121408-4724e9255275/go.mod h1:daVV7qP5qjZbuso7PdcryaAu0sAZbrN9i7WWcTMWvro=
 github.com/prometheus/common v0.62.0 h1:xasJaQlnWAeyHdUBeGjXmutelfJHWMRr+Fg4QszZ2Io=
 github.com/prometheus/common v0.62.0/go.mod h1:vyBcEuLSvWos9B1+CyL7JZ2up+uFzXhkqml0W5zIY1I=
-github.com/prometheus/procfs v0.0.0-20181204211112-1dc9a6cbc91a/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
 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/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 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/auto/sdk v1.1.0 h1:cH53jehLUN6UFLY71z+NDOiNJqDdPRaXzTel0sJySYA=
@@ -101,39 +85,25 @@ go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
 go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
 golang.org/x/crypto v0.40.0 h1:r4x+VvoG5Fm+eJcxMaY8CQM7Lb0l1lsmjGBQ6s8BfKM=
 golang.org/x/crypto v0.40.0/go.mod h1:Qr1vMER5WyS2dfPHAlsOj01wgLbsyWtFn/aY+5+ZdxY=
-golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
-golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
-golang.org/x/net v0.0.0-20181201002055-351d144fa1fc/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
-golang.org/x/net v0.0.0-20190213061140-3a22650c66bd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.42.0 h1:jzkYrhi3YQWD6MLBJcsklgQsoAcw89EcZbJw8Z614hs=
 golang.org/x/net v0.42.0/go.mod h1:FF1RA5d3u7nAYA4z2TkclSCKh68eSXtiFwcWQpPXdt8=
-golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.30.0 h1:dnDm7JmhM45NNpd8FDDeLhK6FwqbOf4MLCM9zb1BOHI=
 golang.org/x/oauth2 v0.30.0/go.mod h1:B++QgG3ZKulg6sRPGD/mqlHQs5rB3Ml9erfeDY7xKlU=
-golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.16.0 h1:ycBJEhp9p4vXvUZNszeOq0kGTPghopOL8q0fq3vstxw=
 golang.org/x/sync v0.16.0/go.mod h1:1dzgHSNfp02xaA81J2MS99Qcpr2w7fw1gpm99rleRqA=
-golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.34.0 h1:H5Y5sJ2L2JRdyv7ROF1he/lPdvFsd0mJHFw2ThKHxLA=
 golang.org/x/sys v0.34.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
-golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.27.0 h1:4fGWRpyh641NLlecmyl4LOe6yDdfaYNrGb2zdfo4JV4=
 golang.org/x/text v0.27.0/go.mod h1:1D28KMCvyooCX9hBiosv5Tz/+YLxj0j7XhWjpSUF7CU=
-golang.org/x/tools v0.0.0-20180828015842-6cd1fcedba52/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 google.golang.org/api v0.241.0 h1:QKwqWQlkc6O895LchPEDUSYr22Xp3NCxpQRiWTB6avE=
 google.golang.org/api v0.241.0/go.mod h1:cOVEm2TpdAGHL2z+UwyS+kmlGr3bVWQQ6sYEqkKje50=
-google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
-google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
 google.golang.org/genproto/googleapis/api v0.0.0-20250603155806-513f23925822 h1:oWVWY3NzT7KJppx2UKhKmzPq4SRe0LdCijVRwvGeikY=
 google.golang.org/genproto/googleapis/api v0.0.0-20250603155806-513f23925822/go.mod h1:h3c4v36UTKzUiuaOKQ6gr3S+0hovBtUrXzTG/i3+XEc=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20250603155806-513f23925822 h1:fc6jSaCT0vBduLYZHYrBBNY4dsWuvgyff9noRNDdBeE=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20250603155806-513f23925822/go.mod h1:qQ0YXyHHx3XkvlzUtpXDkS29lDSafHMZBAZDc03LQ3A=
-google.golang.org/grpc v1.18.0/go.mod h1:6QZJwpn2B+Zp71q/5VxRsJ6NXXVCE5NRUHRo+f3cWCs=
 google.golang.org/grpc v1.73.0 h1:VIWSmpI2MegBtTuFt5/JWy2oXxtjJ/e89Z70ImfD2ok=
 google.golang.org/grpc v1.73.0/go.mod h1:50sbHOUqWoCQGI8V2HQLJM0B+LMlIUjNSZmow7EVBQc=
 google.golang.org/protobuf v1.36.6 h1:z1NpPI8ku2WgiWnf+t9wTPsn6eP1L7ksHUlkfLvd9xY=
 google.golang.org/protobuf v1.36.6/go.mod h1:jduwjTPXsFjZGTmRluh+L6NjiWu7pchiJ2/5YcXBHnY=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-honnef.co/go/tools v0.0.0-20180728063816-88497007e858/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=

pkg/metrics/server.go

@@ -10,10 +10,13 @@ import (
 	"log"
 	"net/http"
 	"net/http/pprof"
+	"sync"
 	"time"
 
 	"github.com/chainguard-dev/clog"
-	grpc_prometheus "github.com/grpc-ecosystem/go-grpc-prometheus"
+
+	grpc_prometheus "github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus"
+	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
@@ -23,6 +26,27 @@ import (
 	"google.golang.org/grpc"
 )
 
+type initStuff struct {
+	serverMetrics *grpc_prometheus.ServerMetrics
+}
+
+var (
+	state = sync.OnceValue(func() initStuff {
+		init := initStuff{}
+
+		init.serverMetrics = grpc_prometheus.NewServerMetrics(
+			grpc_prometheus.WithServerHandlingTimeHistogram(
+				grpc_prometheus.WithHistogramBuckets(
+					[]float64{0.1, 0.25, 0.5, 1, 2.5, 5, 10, 30, 60, 120, 300, 600, 1200, 2400, 3666},
+				),
+			),
+		)
+		prometheus.MustRegister(init.serverMetrics)
+
+		return init
+	})
+)
+
 // Fractions >= 1 will always sample. Fractions < 0 are treated as zero. To
 // respect the parent trace's `SampledFlag`, the `TraceIDRatioBased` sampler
 // should be used as a delegate of a `Parent` sampler.
@@ -61,13 +85,7 @@ func SetupTracer(ctx context.Context) func() {
 }
 
 func RegisterListenAndServe(server *grpc.Server, listenAddr string, enablePprof bool) {
-	grpc_prometheus.Register(server)
-	grpc_prometheus.EnableHandlingTimeHistogram(
-		grpc_prometheus.WithHistogramBuckets(
-			// Odd upper bound to avoid conflating a bounded histogram with a timeout.
-			[]float64{0.1, 0.25, 0.5, 1, 2.5, 5, 10, 30, 60, 120, 300, 600, 1200, 2400, 3666},
-		),
-	)
+	state().serverMetrics.InitializeMetrics(server)
 
 	go func(addr string) {
 		mux := http.NewServeMux()
@@ -101,3 +119,11 @@ func RegisterListenAndServe(server *grpc.Server, listenAddr string, enablePprof
 		}
 	}(listenAddr)
 }
+
+func UnaryServerInterceptor() grpc.UnaryServerInterceptor {
+	return state().serverMetrics.UnaryServerInterceptor()
+}
+
+func StreamServerInterceptor() grpc.StreamServerInterceptor {
+	return state().serverMetrics.StreamServerInterceptor()
+}

pkg/options/options.go

@@ -19,9 +19,10 @@ import (
 
 	"chainguard.dev/go-grpc-kit/pkg/trace"
 	"github.com/chainguard-dev/clog"
+	grpc_prometheus "github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus"
 	grpc_retry "github.com/grpc-ecosystem/go-grpc-middleware/v2/interceptors/retry"
-	grpc_prometheus "github.com/grpc-ecosystem/go-grpc-prometheus"
 	"github.com/kelseyhightower/envconfig"
+	"github.com/prometheus/client_golang/prometheus"
 	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
 	"google.golang.org/api/option"
 	"google.golang.org/grpc"
@@ -36,22 +37,42 @@ type envStruct struct {
 	GrpcClientMaxRetry                     uint `envconfig:"GRPC_CLIENT_MAX_RETRY" default:"0"`
 }
 
-var (
-	envOnce sync.Once
+type initStuff struct {
+	env           envStruct
+	clientMetrics *grpc_prometheus.ClientMetrics
+}
 
-	env envStruct
-)
+var (
+	state = sync.OnceValue(func() initStuff {
+		init := initStuff{}
 
-// Parse these lazily, to allow clients to set their own in their main() or init().
-func getEnv() *envStruct {
-	envOnce.Do(func() {
 		logger := clog.FromContext(context.Background())
-		if err := envconfig.Process("", &env); err != nil {
+		if err := envconfig.Process("", &init.env); err != nil {
 			logger.Warn("Failed to process environment variables", "error", err)
 		}
+
+		hopt := grpc_prometheus.WithHistogramBuckets(
+			[]float64{0.1, 0.25, 0.5, 1, 2.5, 5, 10, 30, 60, 120, 300, 600, 1200, 2400, 3666},
+		)
+
+		cmOpts := []grpc_prometheus.ClientMetricsOption{}
+
+		if init.env.EnableClientHandlingTimeHistogram {
+			cmOpts = append(cmOpts, grpc_prometheus.WithClientHandlingTimeHistogram(hopt))
+		}
+		if init.env.EnableClientStreamReceiveTimeHistogram {
+			cmOpts = append(cmOpts, grpc_prometheus.WithClientStreamRecvHistogram(hopt))
+		}
+		if init.env.EnableClientStreamSendTimeHistogram {
+			cmOpts = append(cmOpts, grpc_prometheus.WithClientStreamSendHistogram(hopt))
+		}
+
+		init.clientMetrics = grpc_prometheus.NewClientMetrics(cmOpts...)
+		prometheus.MustRegister(init.clientMetrics)
+
+		return init
 	})
-	return &env
-}
+)
 
 // ListenerForTest is to support bufnet in our testing.
 var ListenerForTest DialableListener
@@ -98,22 +119,6 @@ var (
 	SendMsgSize = 100 * 1024 * 1024 // 100MB
 )
 
-func enableClientTimeHistogram() {
-	hopt := grpc_prometheus.WithHistogramBuckets(
-		[]float64{0.1, 0.25, 0.5, 1, 2.5, 5, 10, 30, 60, 120, 300, 600},
-	)
-
-	if getEnv().EnableClientHandlingTimeHistogram {
-		grpc_prometheus.EnableClientHandlingTimeHistogram(hopt)
-	}
-	if getEnv().EnableClientStreamReceiveTimeHistogram {
-		grpc_prometheus.EnableClientStreamReceiveTimeHistogram(hopt)
-	}
-	if getEnv().EnableClientStreamSendTimeHistogram {
-		grpc_prometheus.EnableClientStreamSendTimeHistogram(hopt)
-	}
-}
-
 func ClientOptions() []option.ClientOption {
 	do := GRPCDialOptions()
 	cos := make([]option.ClientOption, 0, len(do))
@@ -127,14 +132,14 @@ func ClientOptions() []option.ClientOption {
 func GRPCDialOptions() []grpc.DialOption {
 	retryOpts := []grpc_retry.CallOption{
 		grpc_retry.WithBackoff(grpc_retry.BackoffExponential(100 * time.Millisecond)),
-		grpc_retry.WithMax(getEnv().GrpcClientMaxRetry),
+		grpc_retry.WithMax(state().env.GrpcClientMaxRetry),
 	}
 
 	return []grpc.DialOption{
 		grpc.WithStatsHandler(otelgrpc.NewClientHandler()),
 		grpc.WithStatsHandler(trace.PreserveTraceParentHandler),
-		grpc.WithChainUnaryInterceptor(grpc_prometheus.UnaryClientInterceptor, grpc_retry.UnaryClientInterceptor(retryOpts...)),
-		grpc.WithChainStreamInterceptor(grpc_prometheus.StreamClientInterceptor, grpc_retry.StreamClientInterceptor(retryOpts...)),
+		grpc.WithChainUnaryInterceptor(state().clientMetrics.UnaryClientInterceptor(), grpc_retry.UnaryClientInterceptor(retryOpts...)),
+		grpc.WithChainStreamInterceptor(state().clientMetrics.StreamClientInterceptor(), grpc_retry.StreamClientInterceptor(retryOpts...)),
 	}
 }
 
@@ -146,7 +151,6 @@ func GRPCOptions(delegate url.URL) (string, []grpc.DialOption) {
 		if delegate.Port() != "" {
 			port = delegate.Port()
 		}
-		enableClientTimeHistogram()
 		return net.JoinHostPort(delegate.Hostname(), port), append(GRPCDialOptions(), []grpc.DialOption{
 			grpc.WithTransportCredentials(insecure.NewCredentials()),
 			grpc.WithDefaultCallOptions(
@@ -159,7 +163,6 @@ func GRPCOptions(delegate url.URL) (string, []grpc.DialOption) {
 		if delegate.Port() != "" {
 			port = delegate.Port()
 		}
-		enableClientTimeHistogram()
 		return net.JoinHostPort(delegate.Hostname(), port), append(GRPCDialOptions(), []grpc.DialOption{
 			grpc.WithTransportCredentials(credentials.NewTLS(&tls.Config{
 				MinVersion: tls.VersionTLS12,

pkg/options/options_test.go

@@ -17,21 +17,21 @@ func TestGetEnv(t *testing.T) {
 	old := os.Getenv("GRPC_CLIENT_MAX_RETRY")
 	defer os.Setenv("GRPC_CLIENT_MAX_RETRY", old)
 
-	want := &envStruct{
+	want := envStruct{
 		EnableClientHandlingTimeHistogram:      true,
 		EnableClientStreamReceiveTimeHistogram: true,
 		EnableClientStreamSendTimeHistogram:    true,
 		GrpcClientMaxRetry:                     42,
 	}
 	t.Run("can change env right before usage", func(t *testing.T) {
 		os.Setenv("GRPC_CLIENT_MAX_RETRY", strconv.Itoa(int(want.GrpcClientMaxRetry)))
-		if diff := cmp.Diff(want, getEnv()); diff != "" {
+		if diff := cmp.Diff(want, state().env); diff != "" {
 			t.Errorf("getEnv() -want,+got: %s", diff)
 		}
 	})
 	t.Run("but cannot change after usage", func(t *testing.T) {
 		os.Setenv("GRPC_CLIENT_MAX_RETRY", strconv.Itoa(int(want.GrpcClientMaxRetry+10)))
-		if diff := cmp.Diff(want, getEnv()); diff != "" {
+		if diff := cmp.Diff(want, state().env); diff != "" {
 			t.Errorf("getEnv() -want,+got: %s", diff)
 		}
 	})