Merge branch 'tc-use-promauto' into 'master'

Use promauto to register Prometheus metrics

Closes #1777

See merge request gitlab-org/gitaly!3388

19 files changed, 61 insertions, 128 deletions

diff --git a/auth/token.go b/auth/token.go
index 566557f9c..034be2a86 100644
--- a/auth/token.go
+++ b/auth/token.go
@@ -12,6 +12,7 @@ import (
 
 	grpc_auth "github.com/grpc-ecosystem/go-grpc-middleware/auth"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 )
@@ -27,7 +28,7 @@ var (
 	errUnauthenticated = status.Errorf(codes.Unauthenticated, "authentication required")
 	errDenied          = status.Errorf(codes.PermissionDenied, "permission denied")
 
-	authErrors = prometheus.NewCounterVec(
+	authErrors = promauto.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "gitaly_authentication_errors_total",
 			Help: "Counts of of Gitaly request authentication errors",
@@ -48,10 +49,6 @@ func SetTokenValidityDuration(d time.Duration) {
 	tokenValidityDuration = d
 }
 
-func init() {
-	prometheus.MustRegister(authErrors)
-}
-
 // AuthInfo contains the authentication information coming from a request
 type AuthInfo struct {
 	Version       string
diff --git a/internal/cache/prometheus.go b/internal/cache/prometheus.go
index ee3a7b0a1..f277b40b2 100644
--- a/internal/cache/prometheus.go
+++ b/internal/cache/prometheus.go
@@ -2,71 +2,72 @@ package cache
 
 import (
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 )
 
 var (
-	requestTotals = prometheus.NewCounter(
+	requestTotals = promauto.NewCounter(
 		prometheus.CounterOpts{
 			Name: "gitaly_diskcache_requests_total",
 			Help: "Total number of disk cache requests",
 		},
 	)
-	missTotals = prometheus.NewCounter(
+	missTotals = promauto.NewCounter(
 		prometheus.CounterOpts{
 			Name: "gitaly_diskcache_miss_total",
 			Help: "Total number of disk cache misses",
 		},
 	)
-	bytesStoredtotals = prometheus.NewCounter(
+	bytesStoredtotals = promauto.NewCounter(
 		prometheus.CounterOpts{
 			Name: "gitaly_diskcache_bytes_stored_total",
 			Help: "Total number of disk cache bytes stored",
 		},
 	)
-	bytesFetchedtotals = prometheus.NewCounter(
+	bytesFetchedtotals = promauto.NewCounter(
 		prometheus.CounterOpts{
 			Name: "gitaly_diskcache_bytes_fetched_total",
 			Help: "Total number of disk cache bytes fetched",
 		},
 	)
-	bytesLoserTotals = prometheus.NewCounter(
+	bytesLoserTotals = promauto.NewCounter(
 		prometheus.CounterOpts{
 			Name: "gitaly_diskcache_bytes_loser_total",
 			Help: "Total number of disk cache bytes from losing writes",
 		},
 	)
-	errTotal = prometheus.NewCounterVec(
+	errTotal = promauto.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "gitaly_diskcache_errors_total",
 			Help: "Total number of errors encountered by disk cache",
 		},
 		[]string{"error"},
 	)
-	walkerCheckTotal = prometheus.NewCounter(
+	walkerCheckTotal = promauto.NewCounter(
 		prometheus.CounterOpts{
 			Name: "gitaly_diskcache_walker_check_total",
 			Help: "Total number of events during diskcache filesystem walks",
 		},
 	)
-	walkerRemovalTotal = prometheus.NewCounter(
+	walkerRemovalTotal = promauto.NewCounter(
 		prometheus.CounterOpts{
 			Name: "gitaly_diskcache_walker_removal_total",
 			Help: "Total number of events during diskcache filesystem walks",
 		},
 	)
-	walkerErrorTotal = prometheus.NewCounter(
+	walkerErrorTotal = promauto.NewCounter(
 		prometheus.CounterOpts{
 			Name: "gitaly_diskcache_walker_error_total",
 			Help: "Total number of errors during diskcache filesystem walks",
 		},
 	)
-	walkerEmptyDirTotal = prometheus.NewCounter(
+	walkerEmptyDirTotal = promauto.NewCounter(
 		prometheus.CounterOpts{
 			Name: "gitaly_diskcache_walker_empty_dir_total",
 			Help: "Total number of empty directories encountered",
 		},
 	)
-	walkerEmptyDirRemovalTotal = prometheus.NewCounter(
+	walkerEmptyDirRemovalTotal = promauto.NewCounter(
 		prometheus.CounterOpts{
 			Name: "gitaly_diskcache_walker_empty_dir_removal_total",
 			Help: "Total number of empty directories removed",
@@ -74,20 +75,6 @@ var (
 	)
 )
 
-func init() {
-	prometheus.MustRegister(requestTotals)
-	prometheus.MustRegister(missTotals)
-	prometheus.MustRegister(bytesStoredtotals)
-	prometheus.MustRegister(bytesFetchedtotals)
-	prometheus.MustRegister(bytesLoserTotals)
-	prometheus.MustRegister(errTotal)
-	prometheus.MustRegister(walkerCheckTotal)
-	prometheus.MustRegister(walkerRemovalTotal)
-	prometheus.MustRegister(walkerErrorTotal)
-	prometheus.MustRegister(walkerEmptyDirTotal)
-	prometheus.MustRegister(walkerEmptyDirRemovalTotal)
-}
-
 func countErr(err error) error {
 	switch err {
 	case ErrMissingLeaseFile:
diff --git a/internal/command/metrics.go b/internal/command/metrics.go
index a089b8cd8..e73d1fab0 100644
--- a/internal/command/metrics.go
+++ b/internal/command/metrics.go
@@ -1,14 +1,13 @@
 package command
 
-import "github.com/prometheus/client_golang/prometheus"
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
 
-var inFlightCommandGauge = prometheus.NewGauge(
+var inFlightCommandGauge = promauto.NewGauge(
 	prometheus.GaugeOpts{
 		Name: "gitaly_commands_running",
 		Help: "Total number of processes currently being executed",
 	},
 )
-
-func init() {
-	prometheus.MustRegister(inFlightCommandGauge)
-}
diff --git a/internal/command/spawntoken.go b/internal/command/spawntoken.go
index 623d686d8..95874d88c 100644
--- a/internal/command/spawntoken.go
+++ b/internal/command/spawntoken.go
@@ -8,6 +8,7 @@ import (
 	"github.com/grpc-ecosystem/go-grpc-middleware/logging/logrus/ctxlogrus"
 	"github.com/kelseyhightower/envconfig"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 )
 
 const logDurationThreshold = 5 * time.Millisecond
@@ -16,7 +17,7 @@ var (
 	spawnTokens chan struct{}
 	spawnConfig SpawnConfig
 
-	spawnTimeoutCount = prometheus.NewCounter(
+	spawnTimeoutCount = promauto.NewCounter(
 		prometheus.CounterOpts{
 			Name: "gitaly_spawn_timeouts_total",
 			Help: "Number of process spawn timeouts",
@@ -46,7 +47,6 @@ type SpawnConfig struct {
 func init() {
 	envconfig.MustProcess("gitaly_command_spawn", &spawnConfig)
 	spawnTokens = make(chan struct{}, spawnConfig.MaxParallel)
-	prometheus.MustRegister(spawnTimeoutCount)
 }
 
 func getSpawnToken(ctx context.Context) (putToken func(), err error) {
diff --git a/internal/connectioncounter/connectioncounter.go b/internal/connectioncounter/connectioncounter.go
index 0fbf3210b..1b4bd0b58 100644
--- a/internal/connectioncounter/connectioncounter.go
+++ b/internal/connectioncounter/connectioncounter.go
@@ -4,10 +4,11 @@ import (
 	"net"
 
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 )
 
 var (
-	connTotal = prometheus.NewCounterVec(
+	connTotal = promauto.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "gitaly_connections_total",
 			Help: "Total number of connections accepted by this Gitaly process",
@@ -16,10 +17,6 @@ var (
 	)
 )
 
-func init() {
-	prometheus.MustRegister(connTotal)
-}
-
 // New returns a listener which increments a prometheus counter on each
 // accepted connection. Use cType to specify the connection type, this is
 // a prometheus label.
diff --git a/internal/git/bitmap.go b/internal/git/bitmap.go
index 0ff93b619..58fa2e64e 100644
--- a/internal/git/bitmap.go
+++ b/internal/git/bitmap.go
@@ -9,11 +9,12 @@ import (
 	"github.com/grpc-ecosystem/go-grpc-middleware/logging/logrus/ctxlogrus"
 	grpc_ctxtags "github.com/grpc-ecosystem/go-grpc-middleware/tags"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 	"gitlab.com/gitlab-org/gitaly/internal/git/packfile"
 	"gitlab.com/gitlab-org/gitaly/internal/storage"
 )
 
-var badBitmapRequestCount = prometheus.NewCounterVec(
+var badBitmapRequestCount = promauto.NewCounterVec(
 	prometheus.CounterOpts{
 		Name: "gitaly_bad_bitmap_request_total",
 		Help: "RPC calls during which there was not exactly 1 packfile bitmap",
@@ -21,8 +22,6 @@ var badBitmapRequestCount = prometheus.NewCounterVec(
 	[]string{"method", "bitmaps"},
 )
 
-func init() { prometheus.MustRegister(badBitmapRequestCount) }
-
 // WarnIfTooManyBitmaps checks for too many (more than one) bitmaps in
 // repoPath, and if it finds any, it logs a warning. This is to help us
 // investigate https://gitlab.com/gitlab-org/gitaly/issues/1728.
diff --git a/internal/git/catfile/batch_cache.go b/internal/git/catfile/batch_cache.go
index e68a478bd..4e92954d5 100644
--- a/internal/git/catfile/batch_cache.go
+++ b/internal/git/catfile/batch_cache.go
@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 	"gitlab.com/gitlab-org/gitaly/internal/git/repository"
 	"gitlab.com/gitlab-org/gitaly/internal/gitaly/config"
 )
@@ -20,7 +21,7 @@ const (
 	defaultMaxLen = 100
 )
 
-var catfileCacheMembers = prometheus.NewGauge(
+var catfileCacheMembers = promauto.NewGauge(
 	prometheus.GaugeOpts{
 		Name: "gitaly_catfile_cache_members",
 		Help: "Gauge of catfile cache members",
@@ -30,8 +31,6 @@ var catfileCacheMembers = prometheus.NewGauge(
 var cache *batchCache
 
 func init() {
-	prometheus.MustRegister(catfileCacheMembers)
-
 	config.RegisterHook(func(cfg *config.Cfg) error {
 		cache = newCache(DefaultBatchfileTTL, cfg.Git.CatfileCacheSize)
 		return nil
diff --git a/internal/git/protocol.go b/internal/git/protocol.go
index a562db783..d62163aca 100644
--- a/internal/git/protocol.go
+++ b/internal/git/protocol.go
@@ -7,6 +7,7 @@ import (
 
 	grpc_ctxtags "github.com/grpc-ecosystem/go-grpc-middleware/tags"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 	"gitlab.com/gitlab-org/gitaly/internal/log"
 )
 
@@ -16,7 +17,7 @@ const (
 )
 
 var (
-	gitProtocolRequests = prometheus.NewCounterVec(
+	gitProtocolRequests = promauto.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "gitaly_git_protocol_requests_total",
 			Help: "Counter of Git protocol requests",
@@ -25,10 +26,6 @@ var (
 	)
 )
 
-func init() {
-	prometheus.MustRegister(gitProtocolRequests)
-}
-
 // RequestWithGitProtocol holds requests that respond to GitProtocol
 type RequestWithGitProtocol interface {
 	GetGitProtocol() string
diff --git a/internal/gitaly/rubyserver/worker.go b/internal/gitaly/rubyserver/worker.go
index c5ce991ba..43d2ee65b 100644
--- a/internal/gitaly/rubyserver/worker.go
+++ b/internal/gitaly/rubyserver/worker.go
@@ -6,13 +6,14 @@ import (
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 	log "github.com/sirupsen/logrus"
 	"gitlab.com/gitlab-org/gitaly/internal/gitaly/rubyserver/balancer"
 	"gitlab.com/gitlab-org/gitaly/internal/supervisor"
 )
 
 var (
-	terminationCounter = prometheus.NewCounterVec(
+	terminationCounter = promauto.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "gitaly_ruby_memory_terminations_total",
 			Help: "Number of times gitaly-ruby has been terminated because of excessive memory use.",
@@ -21,10 +22,6 @@ var (
 	)
 )
 
-func init() {
-	prometheus.MustRegister(terminationCounter)
-}
-
 // worker observes the event stream of a supervised process and restarts
 // it if necessary, in cooperation with the balancer.
 type worker struct {
diff --git a/internal/gitaly/server/auth/auth.go b/internal/gitaly/server/auth/auth.go
index 3e0e99514..1227fdf99 100644
--- a/internal/gitaly/server/auth/auth.go
+++ b/internal/gitaly/server/auth/auth.go
@@ -6,6 +6,7 @@ import (
 
 	grpc_auth "github.com/grpc-ecosystem/go-grpc-middleware/auth"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 	gitalyauth "gitlab.com/gitlab-org/gitaly/auth"
 	internalauth "gitlab.com/gitlab-org/gitaly/internal/gitaly/config/auth"
 	"google.golang.org/grpc"
@@ -14,7 +15,7 @@ import (
 )
 
 var (
-	authCount = prometheus.NewCounterVec(
+	authCount = promauto.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "gitaly_authentications_total",
 			Help: "Counts of of Gitaly request authentication attempts",
@@ -23,10 +24,6 @@ var (
 	)
 )
 
-func init() {
-	prometheus.MustRegister(authCount)
-}
-
 // StreamServerInterceptor checks for Gitaly bearer tokens.
 func StreamServerInterceptor(conf internalauth.Config) grpc.StreamServerInterceptor {
 	return grpc_auth.StreamServerInterceptor(checkFunc(conf))
diff --git a/internal/gitaly/service/commit/list_commits_by_oid.go b/internal/gitaly/service/commit/list_commits_by_oid.go
index 1d5efb6c2..b0a6463d3 100644
--- a/internal/gitaly/service/commit/list_commits_by_oid.go
+++ b/internal/gitaly/service/commit/list_commits_by_oid.go
@@ -3,6 +3,7 @@ package commit
 import (
 	"github.com/golang/protobuf/proto"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 	"gitlab.com/gitlab-org/gitaly/internal/git"
 	"gitlab.com/gitlab-org/gitaly/internal/git/catfile"
 	gitlog "gitlab.com/gitlab-org/gitaly/internal/git/log"
@@ -11,7 +12,7 @@ import (
 )
 
 var (
-	listCommitsbyOidHistogram = prometheus.NewHistogram(
+	listCommitsbyOidHistogram = promauto.NewHistogram(
 		prometheus.HistogramOpts{
 			Name: "gitaly_list_commits_by_oid_request_size",
 			Help: "Number of commits requested in a ListCommitsByOid request",
@@ -23,10 +24,6 @@ var (
 		})
 )
 
-func init() {
-	prometheus.MustRegister(listCommitsbyOidHistogram)
-}
-
 func (s *server) ListCommitsByOid(in *gitalypb.ListCommitsByOidRequest, stream gitalypb.CommitService_ListCommitsByOidServer) error {
 	ctx := stream.Context()
 
diff --git a/internal/gitaly/service/smarthttp/cache.go b/internal/gitaly/service/smarthttp/cache.go
index 2b723103a..0d2cfc8bb 100644
--- a/internal/gitaly/service/smarthttp/cache.go
+++ b/internal/gitaly/service/smarthttp/cache.go
@@ -9,6 +9,7 @@ import (
 	"github.com/golang/protobuf/proto"
 	"github.com/grpc-ecosystem/go-grpc-middleware/logging/logrus/ctxlogrus"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 	log "github.com/sirupsen/logrus"
 	"gitlab.com/gitlab-org/gitaly/internal/cache"
 	"gitlab.com/gitlab-org/gitaly/proto/go/gitalypb"
@@ -35,13 +36,13 @@ func newInfoRefCache(streamer streamer) infoRefCache {
 
 var (
 	// prometheus counters
-	cacheAttemptTotal = prometheus.NewCounter(
+	cacheAttemptTotal = promauto.NewCounter(
 		prometheus.CounterOpts{
 			Name: "gitaly_inforef_cache_attempt_total",
 			Help: "Total number of smarthttp info-ref RPCs accessing the cache",
 		},
 	)
-	hitMissTotals = prometheus.NewCounterVec(
+	hitMissTotals = promauto.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "gitaly_inforef_cache_hit_miss_total",
 			Help: "Total number of smarthttp info-ref RPCs accessing the cache",
@@ -56,11 +57,6 @@ var (
 	countErr     = func() { hitMissTotals.WithLabelValues("err").Inc() }
 )
 
-func init() {
-	prometheus.MustRegister(cacheAttemptTotal)
-	prometheus.MustRegister(hitMissTotals)
-}
-
 func (c infoRefCache) tryCache(ctx context.Context, in *gitalypb.InfoRefsRequest, w io.Writer, missFn func(io.Writer) error) error {
 	if len(in.GetGitConfigOptions()) > 0 ||
 		len(in.GetGitProtocol()) > 0 {
diff --git a/internal/metadata/featureflag/grpc_header.go b/internal/metadata/featureflag/grpc_header.go
index c35404c84..fa1053558 100644
--- a/internal/metadata/featureflag/grpc_header.go
+++ b/internal/metadata/featureflag/grpc_header.go
@@ -8,6 +8,7 @@ import (
 	"strings"
 
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 	"google.golang.org/grpc/metadata"
 )
 
@@ -19,7 +20,7 @@ var (
 	// purposes such that we can run integration tests with feature flags.
 	featureFlagsOverride = os.Getenv("GITALY_TESTING_ENABLE_ALL_FEATURE_FLAGS")
 
-	flagChecks = prometheus.NewCounterVec(
+	flagChecks = promauto.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "gitaly_feature_flag_checks_total",
 			Help: "Number of enabled/disabled checks for Gitaly server side feature flags",
@@ -28,10 +29,6 @@ var (
 	)
 )
 
-func init() {
-	prometheus.MustRegister(flagChecks)
-}
-
 // Delim is a delimiter used between a feature flag name and its value.
 const Delim = ":"
 
diff --git a/internal/middleware/cache/prometheus.go b/internal/middleware/cache/prometheus.go
index 949945382..8e5683065 100644
--- a/internal/middleware/cache/prometheus.go
+++ b/internal/middleware/cache/prometheus.go
@@ -2,24 +2,25 @@ package cache
 
 import (
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 	"gitlab.com/gitlab-org/gitaly/internal/praefect/protoregistry"
 )
 
 var (
-	rpcTotal = prometheus.NewCounter(
+	rpcTotal = promauto.NewCounter(
 		prometheus.CounterOpts{
 			Name: "gitaly_cacheinvalidator_rpc_total",
 			Help: "Total number of RPCs encountered by cache invalidator",
 		},
 	)
-	rpcOpTypes = prometheus.NewCounterVec(
+	rpcOpTypes = promauto.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "gitaly_cacheinvalidator_optype_total",
 			Help: "Total number of operation types encountered by cache invalidator",
 		},
 		[]string{"type"},
 	)
-	methodErrTotals = prometheus.NewCounterVec(
+	methodErrTotals = promauto.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "gitaly_cacheinvalidator_error_total",
 			Help: "Total number of cache invalidation errors by method",
@@ -28,12 +29,6 @@ var (
 	)
 )
 
-func init() {
-	prometheus.MustRegister(rpcTotal)
-	prometheus.MustRegister(rpcOpTypes)
-	prometheus.MustRegister(methodErrTotals)
-}
-
 // counter functions are package vars to allow for overriding in tests
 var (
 	countMethodErr = func(method string) { methodErrTotals.WithLabelValues(method).Inc() }
diff --git a/internal/middleware/limithandler/metrics.go b/internal/middleware/limithandler/metrics.go
index f8200180a..399fe4ac1 100644
--- a/internal/middleware/limithandler/metrics.go
+++ b/internal/middleware/limithandler/metrics.go
@@ -7,13 +7,14 @@ import (
 
 	"github.com/grpc-ecosystem/go-grpc-middleware/logging/logrus/ctxlogrus"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 )
 
 const acquireDurationLogThreshold = 10 * time.Millisecond
 
 var (
 	histogramVec       *prometheus.HistogramVec
-	inprogressGaugeVec = prometheus.NewGaugeVec(
+	inprogressGaugeVec = promauto.NewGaugeVec(
 		prometheus.GaugeOpts{
 			Namespace: "gitaly",
 			Subsystem: "rate_limiting",
@@ -23,7 +24,7 @@ var (
 		[]string{"system", "grpc_service", "grpc_method"},
 	)
 
-	queuedGaugeVec = prometheus.NewGaugeVec(
+	queuedGaugeVec = promauto.NewGaugeVec(
 		prometheus.GaugeOpts{
 			Namespace: "gitaly",
 			Subsystem: "rate_limiting",
@@ -40,10 +41,6 @@ type promMonitor struct {
 	histogram       prometheus.Observer
 }
 
-func init() {
-	prometheus.MustRegister(inprogressGaugeVec, queuedGaugeVec)
-}
-
 func splitMethodName(fullMethodName string) (string, string) {
 	fullMethodName = strings.TrimPrefix(fullMethodName, "/") // remove leading slash
 	if i := strings.Index(fullMethodName, "/"); i >= 0 {
@@ -62,12 +59,10 @@ func EnableAcquireTimeHistogram(buckets []float64) {
 		Buckets:   buckets,
 	}
 
-	histogramVec = prometheus.NewHistogramVec(
+	histogramVec = promauto.NewHistogramVec(
 		histogramOpts,
 		[]string{"system", "grpc_service", "grpc_method"},
 	)
-
-	prometheus.MustRegister(histogramVec)
 }
 
 func (c *promMonitor) Queued(ctx context.Context) {
diff --git a/internal/middleware/metadatahandler/metadatahandler.go b/internal/middleware/metadatahandler/metadatahandler.go
index cfe5cb1a4..8025200b3 100644
--- a/internal/middleware/metadatahandler/metadatahandler.go
+++ b/internal/middleware/metadatahandler/metadatahandler.go
@@ -7,6 +7,7 @@ import (
 	grpc_ctxtags "github.com/grpc-ecosystem/go-grpc-middleware/tags"
 	grpc_prometheus "github.com/grpc-ecosystem/go-grpc-prometheus"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 	gitalyauth "gitlab.com/gitlab-org/gitaly/auth"
 	"gitlab.com/gitlab-org/gitaly/internal/helper"
 	"gitlab.com/gitlab-org/labkit/correlation"
@@ -15,7 +16,7 @@ import (
 )
 
 var (
-	requests = prometheus.NewCounterVec(
+	requests = promauto.NewCounterVec(
 		prometheus.CounterOpts{
 			Namespace: "gitaly",
 			Subsystem: "service",
@@ -33,10 +34,6 @@ type metadataTags struct {
 	deadlineType string
 }
 
-func init() {
-	prometheus.MustRegister(requests)
-}
-
 // CallSiteKey is the key used in ctx_tags to store the client feature
 const CallSiteKey = "grpc.meta.call_site"
 
diff --git a/internal/praefect/metrics/prometheus.go b/internal/praefect/metrics/prometheus.go
index 1c366fe93..ef40a68fb 100644
--- a/internal/praefect/metrics/prometheus.go
+++ b/internal/praefect/metrics/prometheus.go
@@ -2,6 +2,7 @@ package metrics
 
 import (
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 	promconfig "gitlab.com/gitlab-org/gitaly/internal/gitaly/config/prometheus"
 	"gitlab.com/gitlab-org/gitaly/internal/prometheus/metrics"
 )
@@ -53,7 +54,7 @@ func RegisterNodeLatency(conf promconfig.Config) (metrics.HistogramVec, error) {
 	return nodeLatency, prometheus.Register(nodeLatency)
 }
 
-var MethodTypeCounter = prometheus.NewCounterVec(
+var MethodTypeCounter = promauto.NewCounterVec(
 	prometheus.CounterOpts{
 		Namespace: "gitaly",
 		Subsystem: "praefect",
@@ -61,7 +62,7 @@ var MethodTypeCounter = prometheus.NewCounterVec(
 	}, []string{"method_type"},
 )
 
-var PrimaryGauge = prometheus.NewGaugeVec(
+var PrimaryGauge = promauto.NewGaugeVec(
 	prometheus.GaugeOpts{
 		Namespace: "gitaly",
 		Subsystem: "praefect",
@@ -69,7 +70,7 @@ var PrimaryGauge = prometheus.NewGaugeVec(
 	}, []string{"virtual_storage", "gitaly_storage"},
 )
 
-var NodeLastHealthcheckGauge = prometheus.NewGaugeVec(
+var NodeLastHealthcheckGauge = promauto.NewGaugeVec(
 	prometheus.GaugeOpts{
 		Namespace: "gitaly",
 		Subsystem: "praefect",
@@ -77,7 +78,7 @@ var NodeLastHealthcheckGauge = prometheus.NewGaugeVec(
 	}, []string{"gitaly_storage"},
 )
 
-var ChecksumMismatchCounter = prometheus.NewCounterVec(
+var ChecksumMismatchCounter = promauto.NewCounterVec(
 	prometheus.CounterOpts{
 		Namespace: "gitaly",
 		Subsystem: "praefect",
@@ -86,7 +87,7 @@ var ChecksumMismatchCounter = prometheus.NewCounterVec(
 )
 
 // ReadDistribution counts how many read operations was routed to each storage.
-var ReadDistribution = prometheus.NewCounterVec(
+var ReadDistribution = promauto.NewCounterVec(
 	prometheus.CounterOpts{
 		Namespace: "gitaly",
 		Subsystem: "praefect",
@@ -95,13 +96,3 @@ var ReadDistribution = prometheus.NewCounterVec(
 	},
 	[]string{"virtual_storage", "storage"},
 )
-
-func init() {
-	prometheus.MustRegister(
-		MethodTypeCounter,
-		PrimaryGauge,
-		ChecksumMismatchCounter,
-		NodeLastHealthcheckGauge,
-		ReadDistribution,
-	)
-}
diff --git a/internal/supervisor/monitor.go b/internal/supervisor/monitor.go
index a5f609cf6..9f15f7923 100644
--- a/internal/supervisor/monitor.go
+++ b/internal/supervisor/monitor.go
@@ -4,19 +4,20 @@ import (
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 	log "github.com/sirupsen/logrus"
 	"gitlab.com/gitlab-org/gitaly/internal/ps"
 )
 
 var (
-	rssGauge = prometheus.NewGaugeVec(
+	rssGauge = promauto.NewGaugeVec(
 		prometheus.GaugeOpts{
 			Name: "gitaly_supervisor_rss_bytes",
 			Help: "Resident set size of supervised processes, in bytes.",
 		},
 		[]string{"name"},
 	)
-	healthCounter = prometheus.NewCounterVec(
+	healthCounter = promauto.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "gitaly_supervisor_health_checks_total",
 			Help: "Count of Gitaly supervisor health checks",
@@ -25,11 +26,6 @@ var (
 	)
 )
 
-func init() {
-	prometheus.MustRegister(rssGauge)
-	prometheus.MustRegister(healthCounter)
-}
-
 type monitorProcess struct {
 	pid  int
 	wait <-chan struct{}
diff --git a/internal/supervisor/supervisor.go b/internal/supervisor/supervisor.go
index c6c9a7e22..c13e75948 100644
--- a/internal/supervisor/supervisor.go
+++ b/internal/supervisor/supervisor.go
@@ -10,6 +10,7 @@ import (
 
 	"github.com/kelseyhightower/envconfig"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 	log "github.com/sirupsen/logrus"
 	"gitlab.com/gitlab-org/labkit/tracing"
 )
@@ -25,7 +26,7 @@ type Config struct {
 }
 
 var (
-	startCounter = prometheus.NewCounterVec(
+	startCounter = promauto.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "gitaly_supervisor_starts_total",
 			Help: "Number of starts of supervised processes.",
@@ -39,7 +40,6 @@ var (
 
 func init() {
 	envconfig.MustProcess("gitaly_supervisor", &config)
-	prometheus.MustRegister(startCounter)
 }
 
 // Process represents a running process.