Use golangci-lint

.golangci.yml

@@ -0,0 +1,36 @@
+run:
+  deadline: 5m
+
+linters:
+  disable-all: true
+  enable:
+    - bodyclose
+    - dogsled
+    - dupl
+    - errcheck
+    - exportloopref
+    - gocritic
+    - gocyclo
+    - gofmt
+    - goimports
+    - gosec
+    - goprintffuncname
+    - gosimple
+    - govet
+    - ineffassign
+    - misspell
+    - nakedret
+    - nolintlint
+    - revive
+    - staticcheck
+    - typecheck
+    - unconvert
+    - unused
+    - whitespace
+
+linters-settings:
+  goimports:
+    local-prefixes: sigs.k8s.io/custom-metrics-apiserver
+  misspell:
+    ignore-words:
+      - "creater" # Cf. e.g. https://pkg.go.dev/k8s.io/apimachinery@v0.24.3/pkg/runtime#ObjectCreater

Makefile

@@ -3,12 +3,19 @@ IMAGE?=k8s-test-metrics-adapter
 TEMP_DIR:=$(shell mktemp -d)
 ARCH?=amd64
 OUT_DIR?=./_output
+GOPATH:=$(shell go env GOPATH)
 
 VERSION?=latest
 
+GOLANGCI_VERSION:=1.50.1
+
 .PHONY: all
 all: build-test-adapter
 
+
+# Generate
+# --------
+
 generated_openapis := core custommetrics externalmetrics
 generated_files := $(generated_openapis:%=pkg/generated/openapi/%/zz_generated.openapi.go)
 
@@ -26,26 +33,49 @@ pkg/generated/openapi/%/zz_generated.openapi.go: go.mod go.sum
 	    -o ./ \
 	    -r /dev/null
 
+
+# Build
+# -----
+
 .PHONY: build-test-adapter
 build-test-adapter: $(generated_files)
 	CGO_ENABLED=0 GOOS=linux GOARCH=$(ARCH) go build -o $(OUT_DIR)/$(ARCH)/test-adapter sigs.k8s.io/custom-metrics-apiserver/test-adapter
 
-.PHONY: gofmt
-gofmt:
-	./hack/gofmt-all.sh
+
+# Format and lint
+# ---------------
+
+HAS_GOLANGCI_VERSION:=$(shell $(GOPATH)/bin/golangci-lint version --format=short)
+.PHONY: golangci
+golangci:
+ifneq ($(HAS_GOLANGCI_VERSION), $(GOLANGCI_VERSION))
+	curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(GOPATH)/bin v$(GOLANGCI_VERSION)
+endif
+
+.PHONY: verify-lint
+verify-lint: golangci
+	$(GOPATH)/bin/golangci-lint run --modules-download-mode=readonly || (echo 'Run "make update-lint"' && exit 1)
+
+.PHONY: update-lint
+update-lint: golangci
+	$(GOPATH)/bin/golangci-lint run --fix --modules-download-mode=readonly
+
+
+# Verify
+# ------
 
 .PHONY: verify
-verify: verify-deps verify-gofmt
+verify: verify-deps verify-lint
 
 .PHONY: verify-deps
 verify-deps:
 	go mod verify
 	go mod tidy
 	@git diff --exit-code -- go.sum go.mod
 
-.PHONY: verify-gofmt
-verify-gofmt:
-	./hack/gofmt-all.sh -v
+
+# Test
+# ----
 
 .PHONY: test
 test:

pkg/apiserver/apiserver.go

@@ -21,12 +21,13 @@ import (
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/runtime/serializer"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	"k8s.io/apimachinery/pkg/version"
 	genericapiserver "k8s.io/apiserver/pkg/server"
 	"k8s.io/client-go/informers"
-
 	cminstall "k8s.io/metrics/pkg/apis/custom_metrics/install"
 	eminstall "k8s.io/metrics/pkg/apis/external_metrics/install"
+
 	"sigs.k8s.io/custom-metrics-apiserver/pkg/apiserver/installer"
 	"sigs.k8s.io/custom-metrics-apiserver/pkg/provider"
 )
@@ -41,7 +42,7 @@ func init() {
 	eminstall.Install(Scheme)
 
 	// we need custom conversion functions to list resources with options
-	installer.RegisterConversions(Scheme)
+	utilruntime.Must(installer.RegisterConversions(Scheme))
 
 	// we need to add the options to empty v1
 	// TODO fix the server code to avoid this
@@ -69,24 +70,24 @@ type CustomMetricsAdapterServer struct {
 	externalMetricsProvider provider.ExternalMetricsProvider
 }
 
-type completedConfig struct {
+type CompletedConfig struct {
 	genericapiserver.CompletedConfig
 }
 
 // Complete fills in any fields not set that are required to have valid data. It's mutating the receiver.
-func (c *Config) Complete(informers informers.SharedInformerFactory) completedConfig {
+func (c *Config) Complete(informers informers.SharedInformerFactory) CompletedConfig {
 	c.GenericConfig.Version = &version.Info{
 		Major: "1",
 		Minor: "0",
 	}
-	return completedConfig{c.GenericConfig.Complete(informers)}
+	return CompletedConfig{c.GenericConfig.Complete(informers)}
 }
 
 // New returns a new instance of CustomMetricsAdapterServer from the given config.
 // name is used to differentiate for logging.
 // Each of the arguments: customMetricsProvider, externalMetricsProvider can be set either to
 // a provider implementation, or to nil to disable one of the APIs.
-func (c completedConfig) New(name string, customMetricsProvider provider.CustomMetricsProvider, externalMetricsProvider provider.ExternalMetricsProvider) (*CustomMetricsAdapterServer, error) {
+func (c CompletedConfig) New(name string, customMetricsProvider provider.CustomMetricsProvider, externalMetricsProvider provider.ExternalMetricsProvider) (*CustomMetricsAdapterServer, error) {
 	genericServer, err := c.CompletedConfig.New(name, genericapiserver.NewEmptyDelegate()) // completion is done in Complete, no need for a second time
 	if err != nil {
 		return nil, err

pkg/apiserver/cmapis.go

@@ -24,8 +24,8 @@ import (
 	genericapi "k8s.io/apiserver/pkg/endpoints"
 	"k8s.io/apiserver/pkg/endpoints/discovery"
 	genericapiserver "k8s.io/apiserver/pkg/server"
-
 	"k8s.io/metrics/pkg/apis/custom_metrics"
+
 	specificapi "sigs.k8s.io/custom-metrics-apiserver/pkg/apiserver/installer"
 	"sigs.k8s.io/custom-metrics-apiserver/pkg/provider"
 	metricstorage "sigs.k8s.io/custom-metrics-apiserver/pkg/registry/custom_metrics"

pkg/apiserver/emapis.go

@@ -24,8 +24,8 @@ import (
 	genericapi "k8s.io/apiserver/pkg/endpoints"
 	"k8s.io/apiserver/pkg/endpoints/discovery"
 	genericapiserver "k8s.io/apiserver/pkg/server"
-
 	"k8s.io/metrics/pkg/apis/external_metrics"
+
 	specificapi "sigs.k8s.io/custom-metrics-apiserver/pkg/apiserver/installer"
 	"sigs.k8s.io/custom-metrics-apiserver/pkg/provider"
 	metricstorage "sigs.k8s.io/custom-metrics-apiserver/pkg/registry/external_metrics"

pkg/apiserver/endpoints/handlers/get.go

@@ -17,7 +17,6 @@ limitations under the License.
 package handlers
 
 import (
-	"fmt"
 	"net/http"
 	"net/url"
 	"strings"
@@ -120,7 +119,7 @@ func ListResourceWithOptions(r cm_rest.ListerWithOptions, scope handlers.Request
 		trace.Step("Listing from storage done")
 
 		responsewriters.WriteObjectNegotiated(scope.Serializer, negotiation.DefaultEndpointRestrictions, scope.Kind.GroupVersion(), w, req, http.StatusOK, result)
-		trace.Step(fmt.Sprintf("Writing http response done"))
+		trace.Step("Writing http response done")
 	}
 }