Merge pull request #45 from roman-khimov/build-fixes

Build fixes

.gitignore

@@ -7,3 +7,11 @@ vendor
 
 # tempfiles
 .DS_Store
+*~
+
+# binary
+bin/
+
+# coverage
+coverage.txt
+coverage.html

.golangci.yml

@@ -0,0 +1,59 @@
+# This file contains all available configuration options
+# with their default values.
+
+# options for analysis running
+run:
+  # timeout for analysis, e.g. 30s, 5m, default is 1m
+  timeout: 5m
+
+  # include test files or not, default is true
+  tests: true
+
+# output configuration options
+output:
+  # colored-line-number|line-number|json|tab|checkstyle|code-climate, default is "colored-line-number"
+  format: tab
+
+# all available settings of specific linters
+linters-settings:
+  exhaustive:
+    # indicates that switch statements are to be considered exhaustive if a
+    # 'default' case is present, even if all enum members aren't listed in the
+    # switch
+    default-signifies-exhaustive: true
+  govet:
+    # report about shadowed variables
+    check-shadowing: false
+
+linters:
+  enable:
+    # mandatory linters
+    - govet
+    - golint
+
+    # some default golangci-lint linters
+    - deadcode
+    - errcheck
+    - gosimple
+    - ineffassign
+    - staticcheck
+    - structcheck
+    - typecheck
+    - unused
+    - varcheck
+
+    # extra linters
+    - exhaustive
+    - godot
+    - gofmt
+    - whitespace
+    - goimports
+  disable-all: true
+  fast: false
+
+issues:
+  include:
+    - EXC0002 # should have a comment
+    - EXC0003 # test/Test ... consider calling this
+    - EXC0004 # govet
+    - EXC0005 # C-style breaks

Dockerfile

@@ -4,36 +4,20 @@ WORKDIR /src
 
 RUN set -x \
     && apt update \
-    && apt install -y upx-ucl
+    && apt install -y make
 
 COPY . /src
 
 ARG VERSION=dev
 
-# https://github.com/golang/go/wiki/Modules#how-do-i-use-vendoring-with-modules-is-vendoring-going-away
-# go build -mod=vendor
-# The -gcflags "all=-N -l" flag helps us get a better debug experience
-RUN set -x \
-    && export BUILD=$(date -u +%s%N) \
-    && export REPO=$(go list -m) \
-    && export LDFLAGS="-X ${REPO}/misc.Version=${VERSION} -X ${REPO}/misc.Build=${BUILD}" \
-    && export GOGC=off \
-    && export CGO_ENABLED=0 \
-    && [ -d "./vendor" ] || go mod vendor \
-    && go build \
-      -v \
-      -mod=vendor \
-      -trimpath \
-      -ldflags "${LDFLAGS}" \
-      -o /go/bin/neofs-s3 ./cmd/gate \
-    && upx -3 /go/bin/neofs-s3
+RUN make
 
 # Executable image
 FROM scratch
 
 WORKDIR /
 
-COPY --from=builder /go/bin/neofs-s3 /bin/neofs-s3
+COPY --from=builder /src/bin/neofs-s3-gw /bin/neofs-s3-gw
 COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
 
-ENTRYPOINT ["/bin/neofs-s3"]
+ENTRYPOINT ["/bin/neofs-s3-gw"]

Makefile

@@ -1,43 +1,106 @@
--include .env
--include help.mk
-
-HUB_IMAGE=nspccdev/neofs
+#!/usr/bin/make -f
 
+REPO ?= $(shell go list -m)
 VERSION ?= "$(shell git describe --tags 2>/dev/null || git rev-parse --short HEAD | sed 's/^v//')"
-BUILD_VERSION ?= "$(shell git describe --abbrev=0 --tags | sed 's/^v//')"
 
-.PHONY: format deps image publish
+BIN_NAME=neofs-s3-gw
+HUB_IMAGE="nspccdev/$(BIN_NAME)"
+HUB_TAG ?= "$(shell echo ${VERSION} | sed 's/^v//')"
+BINDIR = bin
+BIN = "$(BINDIR)/$(BIN_NAME)"
 
-# Show current version
-version:
-	@echo $(BUILD_VERSION)
+.PHONY: help all dep clean format test cover lint docker/lint image-push image dirty-image
+
+# Make all binaries
+all: $(BIN)
+
+$(BIN): $(BINDIR) dep
+	@echo "⇒ Build $@"
+	CGO_ENABLED=0 \
+	go build -v -trimpath \
+	-ldflags "-X main.Version=$(VERSION)" \
+	-o $@ ./cmd/gate
+
+$(BINDIR):
+	@echo "⇒ Ensure dir: $@"
+	@mkdir -p $@
+
+# Pull go dependencies
+dep:
+	@printf "⇒ Download requirements: "
+	@CGO_ENABLED=0 \
+	go mod download && echo OK
+	@printf "⇒ Tidy requirements: "
+	@CGO_ENABLED=0 \
+	go mod tidy -v && echo OK
+
+# Run tests
+test:
+	@go test ./... -cover
+
+# Run tests with race detection and produce coverage output
+cover:
+	@go test -v -race ./... -coverprofile=coverage.txt -covermode=atomic
+	@go tool cover -html=coverage.txt -o coverage.html
 
 # Reformat code
 format:
-	@[ ! -z `which goimports` ] || (echo "install goimports" && exit 2)
-	@for f in `find . -type f -name '*.go' -not -path './vendor/*' -not -name '*.pb.go' -prune`; do \
-		echo "⇒ Processing $$f"; \
-		goimports -w $$f; \
-	done
+	@echo "⇒ Processing gofmt check"
+	@gofmt -s -w ./
+	@echo "⇒ Processing goimports check"
+	@goimports -w ./
 
-# Check and ensure dependencies
-deps:
-	@printf "⇒ Ensure vendor: "
-	@go mod tidy -v && echo OK || (echo fail && exit 2)
-	@printf "⇒ Download requirements: "
-	@go mod download && echo OK || (echo fail && exit 2)
-	@printf "⇒ Store vendor localy: "
-	@go mod vendor && echo OK || (echo fail && exit 2)
-
-# Build current docker image
-image: deps
-	@echo "⇒ Build docker-image"
+# Build clean Docker image
+image:
+	@echo "⇒ Build NeoFS S3 Gateway docker image "
 	@docker build \
-		--build-arg VERSION=$(BUILD_VERSION) \
+		--build-arg REPO=$(REPO) \
+		--build-arg VERSION=$(VERSION) \
+		--rm \
 		-f Dockerfile \
-		 -t $(HUB_IMAGE)-s3-gate:$(BUILD_VERSION) .
+		-t $(HUB_IMAGE):$(HUB_TAG) .
 
-# Publish docker image
-publish:
-	@echo "${B}${G}⇒ publish docker image ${R}"
-	@docker push $(HUB_IMAGE)-s3-gate:$(VERSION)
+# Push Docker image to the hub
+image-push:
+	@echo "⇒ Publish image"
+	@docker push $(HUB_IMAGE):$(HUB_TAG)
+
+# Build dirty Docker image
+dirty-image:
+	@echo "⇒ Build NeoFS S3 Gateway dirty docker image "
+	@docker build \
+		--build-arg REPO=$(REPO) \
+		--build-arg VERSION=$(VERSION) \
+		--rm \
+		-f Dockerfile.dirty \
+		-t $(HUB_IMAGE)-dirty:$(HUB_TAG) .
+
+# Run linters
+lint:
+	@golangci-lint --timeout=5m run
+
+# Run linters in Docker
+docker/lint:
+	docker run --rm -it \
+	-v `pwd`:/src \
+	-u `stat -c "%u:%g" .` \
+	--env HOME=/src \
+	golangci/golangci-lint:v1.40 bash -c 'cd /src/ && make lint'
+
+# Show current version
+version:
+	@echo $(VERSION)
+
+# Show this help prompt
+help:
+	@echo '  Usage:'
+	@echo ''
+	@echo '    make <target>'
+	@echo ''
+	@echo '  Targets:'
+	@echo ''
+	@awk '/^#/{ comment = substr($$0,3) } comment && /^[a-zA-Z][a-zA-Z0-9_-]+ ?:/{ print "   ", $$1, comment }' $(MAKEFILE_LIST) | column -t -s ':' | grep -v 'IGNORE' | sort -u
+
+# Clean up
+clean:
+	rm -rf $(BINDIR)

api/auth/center.go

@@ -24,6 +24,7 @@ import (
 var authorizationFieldRegexp = regexp.MustCompile(`AWS4-HMAC-SHA256 Credential=(?P<access_key_id_cid>[^/]+)/(?P<access_key_id_oid>[^/]+)/(?P<date>[^/]+)/(?P<region>[^/]*)/(?P<service>[^/]+)/aws4_request,\s*SignedHeaders=(?P<signed_header_fields>.+),\s*Signature=(?P<v4_signature>.+)`)
 
 type (
+	// Center is a user authentication interface.
 	Center interface {
 		Authenticate(request *http.Request) (*token.BearerToken, error)
 	}
@@ -33,6 +34,7 @@ type (
 		cli bearer.Credentials
 	}
 
+	// Params stores node connection parameters.
 	Params struct {
 		Client     sdk.Client
 		Logger     *zap.Logger

api/errors.go

@@ -118,7 +118,7 @@ const (
 	ErrInvalidTagDirective
 	// Add new error codes here.
 
-	// SSE-S3 related API errors
+	// SSE-S3 related API errors.
 	ErrInvalidEncryptionMethod
 
 	// Server-Side-Encryption (with Customer provided key) related API errors.
@@ -170,7 +170,7 @@ const (
 	ErrOperationTimedOut
 	ErrOperationMaxedOut
 	ErrInvalidRequest
-	// MinIO storage class error codes
+	// MinIO storage class error codes.
 	ErrInvalidStorageClass
 	ErrBackendDown
 	// Add new extended error codes here.
@@ -192,7 +192,7 @@ const (
 	ErrAdminCredentialsMismatch
 	ErrInsecureClientRequest
 	ErrObjectTampered
-	// Bucket Quota error codes
+	// Bucket Quota error codes.
 	ErrAdminBucketQuotaExceeded
 	ErrAdminNoSuchQuotaConfiguration
 	ErrAdminBucketQuotaDisabled
@@ -205,7 +205,7 @@ const (
 	ErrHealOverlappingPaths
 	ErrIncorrectContinuationToken
 
-	// S3 Select Errors
+	// S3 Select Errors.
 	ErrEmptyRequestBody
 	ErrUnsupportedFunction
 	ErrInvalidExpressionType
@@ -1625,7 +1625,7 @@ func GetAPIError(code ErrorCode) Error {
 }
 
 // getErrorResponse gets in standard error and resource value and
-// provides a encodable populated response values
+// provides a encodable populated response values.
 func getAPIErrorResponse(ctx context.Context, err error, resource, requestID, hostID string) ErrorResponse {
 	code := "BadRequest"
 	desc := err.Error()
@@ -1803,21 +1803,21 @@ func (e BucketLifecycleNotFound) Error() string {
 	return "No bucket lifecycle configuration found for bucket : " + e.Bucket
 }
 
-// BucketSSEConfigNotFound - no bucket encryption found
+// BucketSSEConfigNotFound - no bucket encryption found.
 type BucketSSEConfigNotFound GenericError
 
 func (e BucketSSEConfigNotFound) Error() string {
 	return "No bucket encryption configuration found for bucket: " + e.Bucket
 }
 
-// BucketTaggingNotFound - no bucket tags found
+// BucketTaggingNotFound - no bucket tags found.
 type BucketTaggingNotFound GenericError
 
 func (e BucketTaggingNotFound) Error() string {
 	return "No bucket tags found for bucket: " + e.Bucket
 }
 
-// BucketObjectLockConfigNotFound - no bucket object lock config found
+// BucketObjectLockConfigNotFound - no bucket object lock config found.
 type BucketObjectLockConfigNotFound GenericError
 
 func (e BucketObjectLockConfigNotFound) Error() string {
@@ -1874,7 +1874,7 @@ func (e ObjectNamePrefixAsSlash) Error() string {
 	return "Object name contains forward slash as pefix: " + e.Bucket + "#" + e.Object
 }
 
-// AllAccessDisabled All access to this object has been disabled
+// AllAccessDisabled All access to this object has been disabled.
 type AllAccessDisabled GenericError
 
 // Error returns string an error formatted as the given text.
@@ -1945,7 +1945,7 @@ func (e InvalidUploadID) Error() string {
 	return "Invalid upload id " + e.UploadID
 }
 
-// InvalidPart One or more of the specified parts could not be found
+// InvalidPart One or more of the specified parts could not be found.
 type InvalidPart struct {
 	PartNumber int
 	ExpETag    string
@@ -1975,21 +1975,21 @@ func (e PartTooBig) Error() string {
 	return "Part size bigger than the allowed limit"
 }
 
-// InvalidETag error returned when the etag has changed on disk
+// InvalidETag error returned when the etag has changed on disk.
 type InvalidETag struct{}
 
 func (e InvalidETag) Error() string {
 	return "etag of the object has changed"
 }
 
-// NotImplemented If a feature is not implemented
+// NotImplemented If a feature is not implemented.
 type NotImplemented struct{}
 
 func (e NotImplemented) Error() string {
 	return "Not Implemented"
 }
 
-// UnsupportedMetadata - unsupported metadata
+// UnsupportedMetadata - unsupported metadata.
 type UnsupportedMetadata struct{}
 
 func (e UnsupportedMetadata) Error() string {
@@ -2003,14 +2003,14 @@ func (e BackendDown) Error() string {
 	return "Backend down"
 }
 
-// PreConditionFailed - Check if copy precondition failed
+// PreConditionFailed - Check if copy precondition failed.
 type PreConditionFailed struct{}
 
 func (e PreConditionFailed) Error() string {
 	return "At least one of the pre-conditions you specified did not hold"
 }
 
-// DeleteError - returns when cant remove object
+// DeleteError - returns when cant remove object.
 type DeleteError struct {
 	Err    error
 	Object string

api/handler/api.go

@@ -14,6 +14,7 @@ type (
 		obj layer.Client
 	}
 
+	// Params holds logger and client.
 	Params struct {
 		Log *zap.Logger
 		Obj layer.Client
@@ -24,6 +25,7 @@ const notSupported = "Not supported by NeoFS S3 Gate: "
 
 var _ api.Handler = (*handler)(nil)
 
+// New creates new api.Handler using given logger and client.
 func New(log *zap.Logger, obj layer.Client) (api.Handler, error) {
 	switch {
 	case obj == nil:

api/handler/delete.go

@@ -68,7 +68,7 @@ func (h *handler) DeleteObjectHandler(w http.ResponseWriter, r *http.Request) {
 	w.WriteHeader(http.StatusNoContent)
 }
 
-// DeleteMultipleObjectsHandler :
+// DeleteMultipleObjectsHandler handles multiple delete requests.
 func (h *handler) DeleteMultipleObjectsHandler(w http.ResponseWriter, r *http.Request) {
 	var (
 		req = mux.Vars(r)

api/handler/head.go

@@ -109,7 +109,7 @@ func (h *handler) HeadBucketHandler(w http.ResponseWriter, r *http.Request) {
 
 		code := http.StatusBadRequest
 		if st, ok := status.FromError(err); ok && st != nil {
-			switch st.Code() {
+			switch st.Code() { //nolint:exhaustive // we have default value set above
 			case codes.NotFound:
 				code = http.StatusNotFound
 			case codes.PermissionDenied:

api/handler/list.go

@@ -22,12 +22,14 @@ type listObjectsArgs struct {
 	Version   string
 }
 
+// VersioningConfiguration contains VersioningConfiguration XML representation.
 type VersioningConfiguration struct {
 	XMLName xml.Name `xml:"VersioningConfiguration"`
 	Text    string   `xml:",chardata"`
 	Xmlns   string   `xml:"xmlns,attr"`
 }
 
+// ListMultipartUploadsResult contains ListMultipartUploadsResult XML representation.
 type ListMultipartUploadsResult struct {
 	XMLName xml.Name `xml:"ListMultipartUploadsResult"`
 	Text    string   `xml:",chardata"`
@@ -36,6 +38,7 @@ type ListMultipartUploadsResult struct {
 
 var maxObjectList = 10000 // Limit number of objects in a listObjectsResponse/listObjectsVersionsResponse.
 
+// ListBucketsHandler handles bucket listing requests.
 func (h *handler) ListBucketsHandler(w http.ResponseWriter, r *http.Request) {
 	var (
 		err error
@@ -134,6 +137,7 @@ func (h *handler) listObjects(w http.ResponseWriter, r *http.Request) (*listObje
 	return arg, list, nil
 }
 
+// ListObjectsV1Handler handles objects listing requests for API version 1.
 func (h *handler) ListObjectsV1Handler(w http.ResponseWriter, r *http.Request) {
 	var rid = api.GetRequestID(r.Context())
 	if arg, list, err := h.listObjects(w, r); err != nil {
@@ -193,6 +197,7 @@ func encodeV1(arg *listObjectsArgs, list *layer.ListObjectsInfo) *ListObjectsRes
 	return res
 }
 
+// ListObjectsV2Handler handles objects listing requests for API version 2.
 func (h *handler) ListObjectsV2Handler(w http.ResponseWriter, r *http.Request) {
 	var rid = api.GetRequestID(r.Context())
 	if arg, list, err := h.listObjects(w, r); err != nil {
@@ -278,6 +283,7 @@ func parseListObjectArgs(r *http.Request) (*listObjectsArgs, error) {
 	return &res, nil
 }
 
+// GetBucketVersioningHandler implements bucket versioning getter handler.
 func (h *handler) GetBucketVersioningHandler(w http.ResponseWriter, r *http.Request) {
 	var (
 		rid = api.GetRequestID(r.Context())
@@ -299,6 +305,7 @@ func (h *handler) GetBucketVersioningHandler(w http.ResponseWriter, r *http.Requ
 	}
 }
 
+// ListMultipartUploadsHandler implements multipart uploads listing handler.
 func (h *handler) ListMultipartUploadsHandler(w http.ResponseWriter, r *http.Request) {
 	var (
 		rid = api.GetRequestID(r.Context())

api/handler/response.go

@@ -2,7 +2,7 @@ package handler
 
 import "encoding/xml"
 
-// ListBucketsResponse - format for list buckets response
+// ListBucketsResponse - format for list buckets response.
 type ListBucketsResponse struct {
 	XMLName xml.Name `xml:"http://s3.amazonaws.com/doc/2006-03-01/ ListAllMyBucketsResult" json:"-"`
 
@@ -45,13 +45,13 @@ type ListObjectsV2Response struct {
 	EncodingType string `xml:"EncodingType,omitempty"`
 }
 
-// Bucket container for bucket metadata
+// Bucket container for bucket metadata.
 type Bucket struct {
 	Name         string
 	CreationDate string // time string of format "2006-01-02T15:04:05.000Z"
 }
 
-// Owner - bucket owner/principal
+// Owner - bucket owner/principal.
 type Owner struct {
 	ID          string
 	DisplayName string
@@ -87,12 +87,12 @@ type ListObjectsResponse struct {
 	EncodingType string `xml:"EncodingType,omitempty"`
 }
 
-// CommonPrefix container for prefix response in ListObjectsResponse
+// CommonPrefix container for prefix response in ListObjectsResponse.
 type CommonPrefix struct {
 	Prefix string
 }
 
-// Object container for object metadata
+// Object container for object metadata.
 type Object struct {
 	Key          string
 	LastModified string // time string of format "2006-01-02T15:04:05.000Z"
@@ -118,7 +118,7 @@ type LocationResponse struct {
 	Location string   `xml:",chardata"`
 }
 
-// CopyObjectResponse container returns ETag and LastModified of the successfully copied object
+// CopyObjectResponse container returns ETag and LastModified of the successfully copied object.
 type CopyObjectResponse struct {
 	XMLName      xml.Name `xml:"http://s3.amazonaws.com/doc/2006-03-01/ CopyObjectResult" json:"-"`
 	LastModified string   // time string of format "2006-01-02T15:04:05.000Z"
@@ -127,7 +127,6 @@ type CopyObjectResponse struct {
 
 // MarshalXML - StringMap marshals into XML.
 func (s StringMap) MarshalXML(e *xml.Encoder, start xml.StartElement) error {
-
 	tokens := []xml.Token{start}
 
 	for key, value := range s {

api/headers.go

@@ -1,6 +1,6 @@
 package api
 
-// Standard S3 HTTP response constants
+// Standard S3 HTTP response constants.
 const (
 	LastModified       = "Last-Modified"
 	Date               = "Date"

api/layer/container.go

@@ -12,6 +12,7 @@ import (
 )
 
 type (
+	// BucketInfo stores basic bucket data.
 	BucketInfo struct {
 		Name    string
 		CID     *container.ID
@@ -19,6 +20,7 @@ type (
 		Created time.Time
 	}
 
+	// ListObjectsParams represents object listing request parameters.
 	ListObjectsParams struct {
 		Bucket    string
 		Prefix    string

api/layer/layer.go

@@ -25,6 +25,7 @@ type (
 		log *zap.Logger
 	}
 
+	// Params stores basic API parameters.
 	Params struct {
 		Pool       pool.Client
 		Logger     *zap.Logger
@@ -32,6 +33,7 @@ type (
 		Credential neofs.Credentials
 	}
 
+	// GetObjectParams stores object get request parameters.
 	GetObjectParams struct {
 		Bucket string
 		Object string
@@ -40,6 +42,7 @@ type (
 		Writer io.Writer
 	}
 
+	// PutObjectParams stores object put request parameters.
 	PutObjectParams struct {
 		Bucket string
 		Object string
@@ -48,6 +51,7 @@ type (
 		Header map[string]string
 	}
 
+	// CopyObjectParams stores object copy request parameters.
 	CopyObjectParams struct {
 		SrcBucket string
 		DstBucket string
@@ -56,10 +60,12 @@ type (
 		Header    map[string]string
 	}
 
+	// NeoFS provides basic NeoFS interface.
 	NeoFS interface {
 		Get(ctx context.Context, address *object.Address) (*object.Object, error)
 	}
 
+	// Client provides S3 API client interface.
 	Client interface {
 		NeoFS
 
@@ -81,11 +87,13 @@ type (
 )
 
 var (
+	// ErrObjectExists is returned on attempts to create already existing object.
 	ErrObjectExists = errors.New("object exists")
+	// ErrObjectNotExists is returned on attempts to work with non-existing object.
 	ErrObjectNotExists = errors.New("object not exists")
 )
 
-// NewGatewayLayer creates instance of layer. It checks credentials
+// NewLayer creates instance of layer. It checks credentials
 // and establishes gRPC connection with node.
 func NewLayer(log *zap.Logger, cli sdk.Client) Client {
 	return &layer{
@@ -103,7 +111,7 @@ func (n *layer) Owner(ctx context.Context) *owner.ID {
 	return n.cli.Owner()
 }
 
-// Get NeoFS Object by refs.Address (should be used by auth.Center)
+// Get NeoFS Object by refs.Address (should be used by auth.Center).
 func (n *layer) Get(ctx context.Context, address *object.Address) (*object.Object, error) {
 	return n.cli.Object().Get(ctx, address)
 }

api/layer/util.go

@@ -12,6 +12,7 @@ import (
 )
 
 type (
+	// ObjectInfo holds S3 object data.
 	ObjectInfo struct {
 		id    *object.ID
 		isDir bool
@@ -52,6 +53,7 @@ type (
 
 const (
 	rootSeparator = "root://"
+	// PathSeparator is a path components separator string.
 	PathSeparator = string(os.PathSeparator)
 )
 
@@ -140,11 +142,14 @@ func nameFromObject(o *object.Object) (string, string) {
 	return NameFromString(name)
 }
 
+// NameFromString splits name into base file name and directory path.
 func NameFromString(name string) (string, string) {
 	ind := strings.LastIndex(name, PathSeparator)
 	return name[ind+1:], name[:ind+1]
 }
 
+// ID returns object ID from ObjectInfo.
 func (o *ObjectInfo) ID() *object.ID { return o.id }
 
+// IsDir allows to check if object is a directory.
 func (o *ObjectInfo) IsDir() bool { return o.isDir }

api/max-clients.go

@@ -6,6 +6,7 @@ import (
 )
 
 type (
+	// MaxClients provides HTTP handler wrapper with client limit.
 	MaxClients interface {
 		Handle(http.HandlerFunc) http.HandlerFunc
 	}
@@ -18,6 +19,8 @@ type (
 
 const defaultRequestDeadline = time.Second * 30
 
+// NewMaxClientsMiddleware returns MaxClients interface with handler wrapper based on
+// provided count and timeout limits.
 func NewMaxClientsMiddleware(count int, timeout time.Duration) MaxClients {
 	if timeout <= 0 {
 		timeout = defaultRequestDeadline
@@ -29,6 +32,7 @@ func NewMaxClientsMiddleware(count int, timeout time.Duration) MaxClients {
 	}
 }
 
+// Handler wraps HTTP handler function with logic limiting access to it.
 func (m *maxClients) Handle(f http.HandlerFunc) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		if m.pool == nil {

api/metrics/api.go

@@ -20,7 +20,7 @@ type (
 	}
 
 	// HTTPStats holds statistics information about
-	// HTTP requests made by all clients
+	// HTTP requests made by all clients.
 	HTTPStats struct {
 		currentS3Requests HTTPAPIStats
 		totalS3Requests   HTTPAPIStats
@@ -63,8 +63,8 @@ var (
 	)
 )
 
-// collects http metrics for NeoFS S3 Gate in Prometheus specific format
-// and sends to given channel
+// Collects HTTP metrics for NeoFS S3 Gate in Prometheus specific format
+// and sends to given channel.
 func collectHTTPMetrics(ch chan<- prometheus.Metric) {
 	for api, value := range httpStatsMetric.currentS3Requests.Load() {
 		ch <- prometheus.MustNewConstMetric(
@@ -103,6 +103,7 @@ func collectHTTPMetrics(ch chan<- prometheus.Metric) {
 	}
 }
 
+// APIStats wraps http handler for api with basic statistics collection.
 func APIStats(api string, f http.HandlerFunc) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		httpStatsMetric.currentS3Requests.Inc(api)
@@ -176,7 +177,7 @@ func (st *HTTPStats) getOutputBytes() uint64 {
 	return atomic.LoadUint64(&st.totalOutputBytes)
 }
 
-// Update statistics from http request and response data
+// Update statistics from http request and response data.
 func (st *HTTPStats) updateStats(api string, w http.ResponseWriter, r *http.Request, durationSecs float64) {
 	var code int
 
@@ -200,7 +201,7 @@ func (st *HTTPStats) updateStats(api string, w http.ResponseWriter, r *http.Requ
 	}
 }
 
-// WriteHeader - writes http status code
+// WriteHeader - writes http status code.
 func (w *responseWrapper) WriteHeader(code int) {
 	w.Do(func() {
 		w.statusCode = code

api/reqinfo.go

@@ -13,7 +13,7 @@ import (
 )
 
 type (
-	// KeyVal - appended to ReqInfo.Tags
+	// KeyVal - appended to ReqInfo.Tags.
 	KeyVal struct {
 		Key string
 		Val string
@@ -33,6 +33,7 @@ type (
 		tags         []KeyVal // Any additional info not accommodated by above fields
 	}
 
+	// ObjectRequest represents object request data.
 	ObjectRequest struct {
 		Bucket string
 		Object string
@@ -40,7 +41,7 @@ type (
 	}
 )
 
-// Key used for Get/SetReqInfo
+// Key used for Get/SetReqInfo.
 type contextKeyType string
 
 const ctxRequestInfo = contextKeyType("NeoFS-S3-Gate")
@@ -54,7 +55,7 @@ var (
 var (
 	// RFC7239 defines a new "Forwarded: " header designed to replace the
 	// existing use of X-Forwarded-* headers.
-	// e.g. Forwarded: for=192.0.2.60;proto=https;by=203.0.113.43
+	// e.g. Forwarded: for=192.0.2.60;proto=https;by=203.0.113.43.
 	forwarded = http.CanonicalHeaderKey("Forwarded")
 	// Allows for a sub-match of the first value after 'for=' to the next
 	// comma, semi-colon or space. The match is case-insensitive.
@@ -125,7 +126,7 @@ func prepareContext(w http.ResponseWriter, r *http.Request) context.Context {
 		}))
 }
 
-// NewReqInfo :
+// NewReqInfo returns new ReqInfo based on parameters.
 func NewReqInfo(w http.ResponseWriter, r *http.Request, req ObjectRequest) *ReqInfo {
 	return &ReqInfo{
 		API:          req.Method,
@@ -138,7 +139,7 @@ func NewReqInfo(w http.ResponseWriter, r *http.Request, req ObjectRequest) *ReqI
 	}
 }
 
-// AppendTags - appends key/val to ReqInfo.tags
+// AppendTags - appends key/val to ReqInfo.tags.
 func (r *ReqInfo) AppendTags(key string, val string) *ReqInfo {
 	if r == nil {
 		return nil
@@ -149,7 +150,7 @@ func (r *ReqInfo) AppendTags(key string, val string) *ReqInfo {
 	return r
 }
 
-// SetTags - sets key/val to ReqInfo.tags
+// SetTags - sets key/val to ReqInfo.tags.
 func (r *ReqInfo) SetTags(key string, val string) *ReqInfo {
 	if r == nil {
 		return nil
@@ -172,7 +173,7 @@ func (r *ReqInfo) SetTags(key string, val string) *ReqInfo {
 	return r
 }
 
-// GetTags - returns the user defined tags
+// GetTags - returns the user defined tags.
 func (r *ReqInfo) GetTags() []KeyVal {
 	if r == nil {
 		return nil

api/response.go

@@ -14,7 +14,7 @@ import (
 )
 
 type (
-	// ErrorResponse - error response format
+	// ErrorResponse - error response format.
 	ErrorResponse struct {
 		XMLName    xml.Name `xml:"Error" json:"-"`
 		Code       string
@@ -32,11 +32,11 @@ type (
 		// Captures the server string returned in response header.
 		Server string `xml:"-" json:"-"`
 
-		// Underlying HTTP status code for the returned error
+		// Underlying HTTP status code for the returned error.
 		StatusCode int `xml:"-" json:"-"`
 	}
 
-	// APIError structure
+	// Error structure represents API error.
 	Error struct {
 		Code           string
 		Description    string
@@ -117,7 +117,7 @@ var s3ErrorResponseMap = map[string]string{
 	// Add new API errors here.
 }
 
-// WriteErrorResponse writes error headers
+// WriteErrorResponse writes error headers.
 func WriteErrorResponse(ctx context.Context, w http.ResponseWriter, err error, reqURL *url.URL) {
 	code := http.StatusBadRequest
 
@@ -141,7 +141,7 @@ func WriteErrorResponse(ctx context.Context, w http.ResponseWriter, err error, r
 	WriteResponse(w, code, encodedErrorResponse, MimeXML)
 }
 
-// If none of the http routes match respond with appropriate errors
+// If none of the http routes match respond with appropriate errors.
 func errorResponseHandler(w http.ResponseWriter, r *http.Request) {
 	desc := fmt.Sprintf("Unknown API request at %s", r.URL.Path)
 	WriteErrorResponse(r.Context(), w, Error{
@@ -151,7 +151,7 @@ func errorResponseHandler(w http.ResponseWriter, r *http.Request) {
 	}, r.URL)
 }
 
-// Write http common headers
+// Write http common headers.
 func setCommonHeaders(w http.ResponseWriter) {
 	w.Header().Set(hdrServerInfo, "NeoFS-S3-Gate/"+misc.Version)
 	w.Header().Set(hdrAcceptRanges, "bytes")
@@ -168,6 +168,7 @@ func removeSensitiveHeaders(h http.Header) {
 	h.Del(hdrSSECopyKey)
 }
 
+// WriteResponse writes given statusCode and response into w (with mType header if set).
 func WriteResponse(w http.ResponseWriter, statusCode int, response []byte, mType mimeType) {
 	setCommonHeaders(w)
 	if mType != MimeNone {
@@ -214,6 +215,8 @@ func EncodeToResponse(w http.ResponseWriter, response interface{}) error {
 // 	WriteResponse(w, http.StatusOK, response, MimeXML)
 // }
 
+// WriteSuccessResponseHeadersOnly writes HTTP (200) OK response with no data
+// to the client.
 func WriteSuccessResponseHeadersOnly(w http.ResponseWriter) {
 	WriteResponse(w, http.StatusOK, nil, MimeNone)
 }

api/router.go

@@ -14,6 +14,7 @@ import (
 )
 
 type (
+	// Handler is an S3 API handler interface.
 	Handler interface {
 		HeadObjectHandler(http.ResponseWriter, *http.Request)
 		CopyObjectPartHandler(http.ResponseWriter, *http.Request)
@@ -158,6 +159,7 @@ func logErrorResponse(l *zap.Logger) mux.MiddlewareFunc {
 	}
 }
 
+// GetRequestID returns request ID from response writer or context.
 func GetRequestID(v interface{}) string {
 	switch t := v.(type) {
 	case context.Context:
@@ -169,6 +171,8 @@ func GetRequestID(v interface{}) string {
 	}
 }
 
+// Attach adds S3 API handlers from h to r for domains with m client limit using
+// center authentication and log logger.
 func Attach(r *mux.Router, domains []string, m MaxClients, h Handler, center auth.Center, log *zap.Logger) {
 	api := r.PathPrefix(SlashSeparator).Subrouter()
 

api/user-auth.go

@@ -9,6 +9,7 @@ import (
 	"go.uber.org/zap"
 )
 
+// AttachUserAuth adds user authentication via center to router using log for logging.
 func AttachUserAuth(router *mux.Router, center auth.Center, log *zap.Logger) {
 	router.Use(func(h http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -21,7 +22,6 @@ func AttachUserAuth(router *mux.Router, center auth.Center, log *zap.Logger) {
 
 			h.ServeHTTP(w, r.WithContext(
 				sdk.SetBearerToken(r.Context(), token)))
-
 		})
 	})
 }

cmd/gate/app-healthy.go

@@ -7,6 +7,7 @@ import (
 	"github.com/gorilla/mux"
 )
 
+// Healthy is a health check interface.
 type Healthy interface {
 	Status() error
 }

cmd/gate/app-settings.go

@@ -34,8 +34,8 @@ const (
 	defaultMaxClientsDeadline = time.Second * 30
 )
 
-const ( // settings
-	// Logger:
+const ( // Settings.
+	// Logger.
 	cfgLoggerLevel              = "logger.level"
 	cfgLoggerFormat             = "logger.format"
 	cfgLoggerTraceLevel         = "logger.trace_level"
@@ -44,47 +44,47 @@ const ( // settings
 	cfgLoggerSamplingInitial    = "logger.sampling.initial"
 	cfgLoggerSamplingThereafter = "logger.sampling.thereafter"
 
-	// KeepAlive
+	// KeepAlive.
 	cfgKeepaliveTime                = "keepalive.time"
 	cfgKeepaliveTimeout             = "keepalive.timeout"
 	cfgKeepalivePermitWithoutStream = "keepalive.permit_without_stream"
 
-	// Keys
+	// Keys.
 	cfgNeoFSPrivateKey    = "neofs-key"
 	cfgGateAuthPrivateKey = "auth-key"
 
-	// HTTPS/TLS
+	// HTTPS/TLS.
 	cfgTLSKeyFile  = "tls.key_file"
 	cfgTLSCertFile = "tls.cert_file"
 
-	// Timeouts
+	// Timeouts.
 	cfgConnectionTTL  = "con_ttl"
 	cfgConnectTimeout = "connect_timeout"
 	cfgRequestTimeout = "request_timeout"
 	cfgRebalanceTimer = "rebalance_timer"
 
-	// MaxClients
+	// MaxClients.
 	cfgMaxClientsCount    = "max_clients_count"
 	cfgMaxClientsDeadline = "max_clients_deadline"
 
-	// gRPC
+	// gRPC.
 	cfgGRPCVerbose = "verbose"
 
-	// Metrics / Profiler / Web
+	// Metrics / Profiler / Web.
 	cfgEnableMetrics  = "metrics"
 	cfgEnableProfiler = "pprof"
 	cfgListenAddress  = "listen_address"
 	cfgListenDomains  = "listen_domains"
 
-	// Peers
+	// Peers.
 	cfgPeers = "peers"
 
-	// Application
+	// Application.
 	cfgApplicationName      = "app.name"
 	cfgApplicationVersion   = "app.version"
 	cfgApplicationBuildTime = "app.build_time"
 
-	// command line args
+	// Command line args.
 	cmdHelp    = "help"
 	cmdVersion = "version"
 )
@@ -105,10 +105,9 @@ var ignore = map[string]struct{}{
 func (empty) Read([]byte) (int, error) { return 0, io.EOF }
 
 func fetchPeers(l *zap.Logger, v *viper.Viper) map[string]float64 {
-	peers := make(map[string]float64, 0)
+	peers := make(map[string]float64)
 
 	for i := 0; ; i++ {
-
 		key := cfgPeers + "." + strconv.Itoa(i) + "."
 		address := v.GetString(key + "address")
 		weight := v.GetFloat64(key + "weight")

cmd/gate/app.go

@@ -22,6 +22,7 @@ import (
 )
 
 type (
+	// App is the main application structure.
 	App struct {
 		cli pool.Client
 		ctr auth.Center
@@ -179,6 +180,7 @@ func newApp(ctx context.Context, l *zap.Logger, v *viper.Viper) *App {
 	}
 }
 
+// Wait waits for application to finish.
 func (a *App) Wait() {
 	a.log.Info("application started")
 
@@ -192,6 +194,7 @@ func (a *App) Wait() {
 	a.log.Info("application finished")
 }
 
+// Server runs HTTP server to handle S3 API requests.
 func (a *App) Server(ctx context.Context) {
 	var (
 		err  error
@@ -256,6 +259,7 @@ func (a *App) Server(ctx context.Context) {
 	close(a.webDone)
 }
 
+// Worker runs client worker.
 func (a *App) Worker(ctx context.Context) {
 	a.cli.Worker(ctx)
 	a.log.Info("stopping worker")

misc/build.go

@@ -1,12 +1,16 @@
 package misc
 
 const (
+	// ApplicationName is gateway name.
 	ApplicationName = "neofs-s3-gate"
 
+	// Prefix is configuration environment variables prefix.
 	Prefix = "S3_GW"
 )
 
 var (
+	// Build holds build timestamp.
 	Build = "now"
+	// Version contains application version.
 	Version = "dev"
 )