Bump Go, golangci-lint, update GitHub Actions, fix lint issues

.github/workflows/build-test-lint.yml

@@ -9,13 +9,13 @@ jobs:
     name: build
     strategy:
       matrix:
-        go-version: [1.22.x]
+        go-version: [1.25.x]
         goarch: [amd64,arm64,ppc64le,s390x]
         os: [ubuntu-latest]
     runs-on: ${{ matrix.os }}
     steps:
       - name: Set up Go matrix
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
         with:
           go-version: ${{ matrix.go-version }}
 
@@ -57,9 +57,9 @@ jobs:
     name: test
     steps:
       - name: Set up Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
         with:
-          go-version: 1.22.x
+          go-version: 1.25.x
 
       - name: Check out code into the Go module directory
         uses: actions/checkout@v6
@@ -76,9 +76,9 @@ jobs:
     name: test-coverage
     steps:
       - name: Set up Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
         with:
-          go-version: 1.22.x
+          go-version: 1.25.x
 
       - uses: actions/checkout@v6
 
@@ -93,15 +93,14 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Set up Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
         with:
-          go-version: 1.22.x
+          go-version: 1.25.x
       - uses: actions/checkout@v6
       - name: golangci-lint
-        uses: golangci/golangci-lint-action@v3
+        uses: golangci/golangci-lint-action@v8
         with:
-          # Required: the version of golangci-lint is required and must be specified without patch version: we always use the latest patch version.
-          version: v1.63.4
+          version: v2.7.2
 
   hadolint:
     runs-on: ubuntu-latest
@@ -120,9 +119,9 @@ jobs:
     - uses: actions/checkout@v6
 
     - name: Set up Go
-      uses: actions/setup-go@v5
+      uses: actions/setup-go@v6
       with:
-        go-version: 1.22.x
+        go-version: 1.25.x
 
     # if this fails, run go mod tidy
     - name: Check if module files are consistent with code

.golangci.yml

@@ -0,0 +1,100 @@
+version: "2"
+
+run:
+  timeout: 5m
+
+formatters:
+  enable:
+    - gofmt
+    - goimports
+  settings:
+    goimports:
+      local-prefixes:
+        - github.com/k8snetworkplumbingwg/sriov-network-metrics-exporter
+
+linters:
+  default: none
+  enable:
+    - bodyclose
+    - dogsled
+    - dupl
+    - errcheck
+    - copyloopvar
+    - exhaustive
+    - funlen
+    - goconst
+    - gocritic
+    - gocyclo
+    - mnd
+    - goprintffuncname
+    - gosec
+    - govet
+    - ineffassign
+    - lll
+    - misspell
+    - nakedret
+    - prealloc
+    - rowserrcheck
+    - staticcheck
+    - unconvert
+    - unparam
+    - unused
+    - whitespace
+  settings:
+    dupl:
+      threshold: 100
+    funlen:
+      lines: 100
+      statements: 50
+    goconst:
+      min-len: 2
+      min-occurrences: 2
+    gocritic:
+      enabled-tags:
+        - diagnostic
+        - experimental
+        - opinionated
+        - performance
+        - style
+      disabled-checks:
+        - dupImport
+        - ifElseChain
+        - octalLiteral
+        - whyNoLint
+        - wrapperFunc
+        - unnamedResult
+      settings:
+        hugeParam:
+          sizeThreshold: 512
+        rangeValCopy:
+          sizeThreshold: 512
+    gocyclo:
+      min-complexity: 15
+    lll:
+      line-length: 140
+    misspell:
+      locale: US
+    mnd:
+      checks:
+        - argument
+        - case
+        - condition
+        - return
+    prealloc:
+      simple: true
+      range-loops: true
+      for-loops: false
+  exclusions:
+    rules:
+      - path: ".*_test\\.go"
+        linters:
+          - dupl
+          - funlen
+          - goconst
+          - mnd
+          - errcheck
+          - lll
+          - gocritic
+          - staticcheck
+          - unconvert
+

Dockerfile

@@ -1,4 +1,4 @@
-FROM docker.io/golang:alpine as builder
+FROM docker.io/golang:1.25-alpine as builder
 
 RUN apk add --no-cache --virtual build-dependencies build-base linux-headers git
 COPY ./ /usr/src/sriov-network-metrics-exporter

Makefile

@@ -51,13 +51,16 @@ test-coverage:
 	go test ./... -coverprofile cover.out
 	go tool cover -func cover.out
 
-go-lint-install:
-	go install github.com/golangci/golangci-lint/cmd/golangci-lint@v1.63.4
+GOLANGCI_LINT_VER = v2.7.2
+GOLANGCI_LINT = $(GOPATH)/bin/golangci-lint
 
-go-lint: go-lint-install
-	go mod tidy
-	go fmt ./...
-	golangci-lint run --color always -v ./... 
+$(GOLANGCI_LINT): ; $(info  installing golangci-lint...)
+	$Q go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@$(GOLANGCI_LINT_VER)
 
-go-lint-report: go-lint-install
-	golangci-lint run --color always -v ./... &> golangci-lint.txt
+lint: | $(GOLANGCI_LINT) ; $(info  running golangci-lint...) @ ## Run golangci-lint
+	$Q $(GOLANGCI_LINT) run --timeout=5m
+
+go-lint: lint
+
+go-lint-report: | $(GOLANGCI_LINT)
+	$(GOLANGCI_LINT) run --color always -v ./... &> golangci-lint.txt

cmd/sriov-network-metrics-exporter.go

@@ -7,18 +7,24 @@ import (
 	"flag"
 	"log"
 	"net/http"
-
-	"github.com/k8snetworkplumbingwg/sriov-network-metrics-exporter/collectors"
+	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"golang.org/x/time/rate"
+
+	"github.com/k8snetworkplumbingwg/sriov-network-metrics-exporter/collectors"
+)
+
+const (
+	defaultRateBurst         = 10
+	defaultReadHeaderTimeout = 10 * time.Second
 )
 
 var (
 	addr            = flag.String("web.listen-address", ":9808", "Port to listen on for web interface and telemetry.")
 	rateLimit       = flag.Int("web.rate-limit", 1, "Limit for requests per second.")
-	rateBurst       = flag.Int("web.rate-burst", 10, "Maximum per second burst rate for requests.")
+	rateBurst       = flag.Int("web.rate-burst", defaultRateBurst, "Maximum per second burst rate for requests.")
 	metricsEndpoint = "/metrics"
 )
 
@@ -38,8 +44,13 @@ func main() {
 				noBody(promhttp.Handler()), metricsEndpoint)),
 		rate.Limit(*rateLimit), *rateBurst)
 
+	server := &http.Server{
+		Addr:              *addr,
+		Handler:           handlerWithMiddleware,
+		ReadHeaderTimeout: defaultReadHeaderTimeout,
+	}
 	log.Printf("listening on %v", *addr)
-	log.Fatalf("ListenAndServe error: %v", http.ListenAndServe(*addr, handlerWithMiddleware))
+	log.Fatalf("ListenAndServe error: %v", server.ListenAndServe())
 }
 
 func parseAndVerifyFlags() {

cmd/sriov-network-metrics-exporter_test.go

@@ -21,7 +21,7 @@ func TestMain(t *testing.T) {
 var _ = DescribeTable("test endpointOnly handler", // endpointOnly
 	func(endpoint string, expectedResponse int) {
 		recorder := httptest.NewRecorder()
-		request := httptest.NewRequest(http.MethodGet, endpoint, nil)
+		request := httptest.NewRequest(http.MethodGet, endpoint, http.NoBody)
 		handler := endpointOnly(promhttp.Handler(), metricsEndpoint)
 
 		handler.ServeHTTP(recorder, request)
@@ -35,7 +35,7 @@ var _ = DescribeTable("test endpointOnly handler", // endpointOnly
 var _ = DescribeTable("test getOnly handler", // getOnly
 	func(method string, expectedResponse int) {
 		recorder := httptest.NewRecorder()
-		request := httptest.NewRequest(method, metricsEndpoint, nil)
+		request := httptest.NewRequest(method, metricsEndpoint, http.NoBody)
 		handler := getOnly(promhttp.Handler())
 
 		handler.ServeHTTP(recorder, request)
@@ -67,7 +67,7 @@ var _ = DescribeTable("test limitRequests handler", // limitRequests
 		code := http.StatusOK
 		for i := 0; i < requests; i++ {
 			recorder := httptest.NewRecorder()
-			request := httptest.NewRequest(http.MethodGet, metricsEndpoint, nil)
+			request := httptest.NewRequest(http.MethodGet, metricsEndpoint, http.NoBody)
 			handler.ServeHTTP(recorder, request)
 
 			code = recorder.Code

collectors/collectors.go

@@ -1,5 +1,7 @@
-// Package Collectors defines the structure of the collector aggregator and contains the individual collectors used to gather metrics
-// Each collector should be created in its own file with any required command line flags, its collection behavior and its registration method defined.
+// Package collectors defines the structure of the collector aggregator and contains the individual collectors
+// used to gather metrics.
+// Each collector should be created in its own file with any required command line flags, its collection
+// behavior and its registration method defined.
 
 package collectors
 
@@ -22,7 +24,8 @@ var (
 // SriovCollector registers the collectors used for specific data and exposes a Collect method to gather the data
 type SriovCollector []prometheus.Collector
 
-// Register defines a flag for a collector and adds it to the registry of enabled collectors if the flag is set to true - either through the default option or the flag passed on start
+// Register defines a flag for a collector and adds it to the registry of enabled collectors
+// if the flag is set to true - either through the default option or the flag passed on start.
 // Run by each individual collector in its init function.
 func register(name string, enabled bool, collector func() prometheus.Collector) {
 	collectorState[name] = &enabled

collectors/collectors_test.go

@@ -6,6 +6,7 @@ import (
 	"log"
 	"path/filepath"
 	"testing"
+	"testing/fstest"
 	"time"
 
 	. "github.com/onsi/ginkgo/v2"
@@ -81,21 +82,34 @@ var _ = DescribeTable("test registering collector", // register
 
 func assertLogs(logs []string) {
 	for _, log := range logs {
-		Eventually(&buffer).WithTimeout(time.Duration(2 * time.Second)).Should(gbytes.Say(log))
+		Eventually(&buffer).WithTimeout(2 * time.Second).Should(gbytes.Say(log))
 	}
 }
 
 // Replaces filepath.EvalSymlinks with an emulated evaluation to work with the in-memory fs.
 var evalSymlinks = func(path string) (string, error) {
 	path = filepath.Join(filepath.Base(filepath.Dir(path)), filepath.Base(path))
+	dir := filepath.Dir(path)
+	base := filepath.Base(path)
 
-	if stat, err := fs.Stat(devfs, path); err == nil && stat.Mode() == fs.ModeSymlink {
-		if target, err := fs.ReadFile(devfs, path); err == nil {
-			return string(target), nil
-		} else {
-			return "", fmt.Errorf("error")
+	entries, err := fs.ReadDir(devfs, dir)
+	if err != nil {
+		return "", fmt.Errorf("error reading dir: %v", err)
+	}
+
+	for _, entry := range entries {
+		if entry.Name() == base && entry.Type()&fs.ModeSymlink != 0 {
+			// In Go 1.25, fstest.MapFS treats fs.ModeSymlink files as actual symlinks
+			// and tries to follow them, so fs.ReadFile won't work.
+			// Access the MapFS directly to get the symlink target data.
+			if mapFS, ok := devfs.(fstest.MapFS); ok {
+				if mapFile, exists := mapFS[path]; exists {
+					return string(mapFile.Data), nil
+				}
+			}
+			return "", fmt.Errorf("error reading symlink target")
 		}
-	} else {
-		return "", fmt.Errorf("error")
 	}
+
+	return "", fmt.Errorf("not a symlink or not found")
 }

collectors/pod_cpu_link.go

@@ -1,6 +1,7 @@
 package collectors
 
-// kubepodCPUCollector is a Kubernetes focused collector that exposes information about CPUs linked to specific Kubernetes pods through the CPU Manager component in Kubelet
+// kubepodCPUCollector is a Kubernetes focused collector that exposes information about CPUs
+// linked to specific Kubernetes pods through the CPU Manager component in Kubelet
 
 import (
 	"encoding/json"
@@ -21,9 +22,11 @@ import (
 
 var (
 	kubepodcpu        = "kubepodcpu"
-	kubePodCgroupPath = flag.String("path.kubecgroup", "/sys/fs/cgroup/cpuset/kubepods.slice/", "Path for location of kubernetes cgroups on the host system")
+	kubePodCgroupPath = flag.String("path.kubecgroup",
+		"/sys/fs/cgroup/cpuset/kubepods.slice/", "Path for kubernetes cgroups")
 	sysDevSysNodePath = flag.String("path.nodecpuinfo", "/sys/devices/system/node/", "Path for location of system cpu information")
-	cpuCheckPointFile = flag.String("path.cpucheckpoint", "/var/lib/kubelet/cpu_manager_state", "Path for location of cpu manager checkpoint file")
+	cpuCheckPointFile = flag.String("path.cpucheckpoint",
+		"/var/lib/kubelet/cpu_manager_state", "Path for cpu manager checkpoint file")
 
 	kubecgroupfs    fs.FS
 	cpuinfofs       fs.FS
@@ -108,7 +111,7 @@ func (c kubepodCPUCollector) Describe(ch chan<- *prometheus.Desc) {
 func createKubepodCPUCollector() prometheus.Collector {
 	cpuInfo, err := getCPUInfo()
 	if err != nil {
-		//Exporter will fail here if file can not be read.
+		// Exporter will fail here if file can not be read.
 		logFatal("Fatal Error: cpu info for node can not be collected, %v", err.Error())
 	}
 
@@ -154,7 +157,8 @@ func getCPUInfo() (map[string]string, error) {
 // This accounting will create an entry for each guaranteed pod, even if that pod isn't managed by CPU manager
 // i.e. it will still create an entry if the pod is looking for millis of CPU
 // Todo: validate regex matching and evaluate performance of this approach
-// Todo: validate assumptions about directory structure against other runtimes and kubelet config. Plausibly problematic with CgroupsPerQos and other possible future cgroup changes
+// Todo: validate assumptions about directory structure against other runtimes and kubelet config.
+// Plausibly problematic with CgroupsPerQos and other possible future cgroup changes
 func getGuaranteedPodCPUs() ([]podCPULink, error) {
 	links := make([]podCPULink, 0)
 
@@ -259,7 +263,7 @@ func parseCPURange(cpuString string) ([]string, error) {
 		endpoints := strings.Split(r, "-")
 		if len(endpoints) == 1 {
 			cpuList = append(cpuList, endpoints[0])
-		} else if len(endpoints) == 2 {
+		} else if len(endpoints) == 2 { //nolint:mnd
 			start, err := strconv.Atoi(endpoints[0])
 			if err != nil {
 				return cpuList, err