chore: Upgrade golangci-lint to v2

- Migrate the configuration file
- Update the tooling version and CI
- Apply auto-fixes

Signed-off-by: Kemal Akkoyun <[email protected]>

Author: kakkoyun

.github/workflows/golangci-lint.yml

@@ -33,7 +33,7 @@ jobs:
         run: sudo apt-get update && sudo apt-get -y install libsnmp-dev
         if: github.repository == 'prometheus/snmp_exporter'
       - name: Lint
-        uses: golangci/golangci-lint-action@55c2c1448f86e01eaae002a5a3a9624417608d84 # v6.5.2
+        uses: golangci/golangci-lint-action@1481404843c368bc19ca9406f87d6e0fc97bdcfd # v7.0.0
         with:
           args: --verbose
-          version: v1.64.6
+          version: v2.0.2

.golangci.yml

@@ -1,32 +1,48 @@
+version: "2"
 linters:
   enable:
     - depguard
-    - goimports
     - misspell
     - revive
-
-issues:
-  exclude-rules:
-    - path: _test.go
-      linters:
-        - errcheck
-
-linters-settings:
-  depguard:
-    rules:
-      no_exec_policy:
-        files:
-          - "!$test"
-        deny:
-          - pkg: "os/exec"
-            desc: "Using os/exec to run sub processes it not allowed by policy"
-  errcheck:
-    exclude-functions:
+  settings:
+    depguard:
+      rules:
+        no_exec_policy:
+          files:
+            - '!$test'
+          deny:
+            - pkg: os/exec
+              desc: Using os/exec to run sub processes it not allowed by policy
+    errcheck:
       # Used in HTTP handlers, any error is handled by the server itself.
-      - (net/http.ResponseWriter).Write
-  revive:
+      exclude-functions:
+        - (net/http.ResponseWriter).Write
+    revive:
+      rules:
+        - name: unused-parameter
+          severity: warning
+          disabled: true
+  exclusions:
+    generated: lax
+    presets:
+      - comments
+      - common-false-positives
+      - legacy
+      - std-error-handling
     rules:
-      # https://github.com/mgechev/revive/blob/master/RULES_DESCRIPTIONS.md#unused-parameter
-      - name: unused-parameter
-        severity: warning
-        disabled: true
+      - linters:
+          - errcheck
+        path: _test.go
+    paths:
+      - third_party$
+      - builtin$
+      - examples$
+formatters:
+  enable:
+    - goimports
+  exclusions:
+    generated: lax
+    paths:
+      - third_party$
+      - builtin$
+      - examples$

Makefile.common

@@ -61,7 +61,7 @@ PROMU_URL     := https://github.com/prometheus/promu/releases/download/v$(PROMU_
 SKIP_GOLANGCI_LINT :=
 GOLANGCI_LINT :=
 GOLANGCI_LINT_OPTS ?=
-GOLANGCI_LINT_VERSION ?= v1.64.6
+GOLANGCI_LINT_VERSION ?= v2.0.2
 # golangci-lint only supports linux, darwin and windows platforms on i386/amd64/arm64.
 # windows isn't included here because of the path separator being different.
 ifeq ($(GOHOSTOS),$(filter $(GOHOSTOS),linux darwin))

collector/boot_time_bsd.go

@@ -18,9 +18,10 @@
 package collector
 
 import (
+	"log/slog"
+
 	"github.com/prometheus/client_golang/prometheus"
 	"golang.org/x/sys/unix"
-	"log/slog"
 )
 
 type bootTimeCollector struct {

collector/btrfs_linux.go

@@ -69,7 +69,7 @@ func (c *btrfsCollector) Update(ch chan<- prometheus.Metric) error {
 
 	for _, s := range stats {
 		// match up procfs and ioctl info by filesystem UUID (without dashes)
-		var fsUUID = strings.Replace(s.UUID, "-", "", -1)
+		var fsUUID = strings.ReplaceAll(s.UUID, "-", "")
 		ioctlStats := ioctlStatsMap[fsUUID]
 		c.updateBtrfsStats(ch, s, ioctlStats)
 	}

collector/cpu_linux.go

@@ -87,9 +87,9 @@ func NewCPUCollector(logger *slog.Logger) (Collector, error) {
 	isolcpus, err := sfs.IsolatedCPUs()
 	if err != nil {
 		if !os.IsNotExist(err) {
-			return nil, fmt.Errorf("Unable to get isolated cpus: %w", err)
+			return nil, fmt.Errorf("couldn't get isolated cpus: %w", err)
 		}
-		logger.Debug("Could not open isolated file", "error", err)
+		logger.Debug("couldn't open isolated file", "error", err)
 	}
 
 	c := &cpuCollector{

collector/ethtool_linux_test.go

@@ -212,16 +212,18 @@ func (e *EthtoolFixture) LinkInfo(intf string) (ethtool.EthtoolCmd, error) {
 
 		items := strings.Split(line, ": ")
 		if items[0] == "Supported pause frame use" {
-			if items[1] == "Symmetric" {
+			switch items[1] {
+			case "Symmetric":
 				res.Supported |= (1 << unix.ETHTOOL_LINK_MODE_Pause_BIT)
-			} else if items[1] == "Receive-only" {
+			case "Receive-only":
 				res.Supported |= (1 << unix.ETHTOOL_LINK_MODE_Asym_Pause_BIT)
 			}
 		}
 		if items[0] == "Advertised pause frame use" {
-			if items[1] == "Symmetric" {
+			switch items[1] {
+			case "Symmetric":
 				res.Advertising |= (1 << unix.ETHTOOL_LINK_MODE_Pause_BIT)
-			} else if items[1] == "Receive-only" {
+			case "Receive-only":
 				res.Advertising |= (1 << unix.ETHTOOL_LINK_MODE_Asym_Pause_BIT)
 			}
 		}

collector/filesystem_linux.go

@@ -215,8 +215,8 @@ func parseFilesystemLabels(r io.Reader) ([]filesystemLabels, error) {
 
 		// Ensure we handle the translation of \040 and \011
 		// as per fstab(5).
-		parts[4] = strings.Replace(parts[4], "\\040", " ", -1)
-		parts[4] = strings.Replace(parts[4], "\\011", "\t", -1)
+		parts[4] = strings.ReplaceAll(parts[4], "\\040", " ")
+		parts[4] = strings.ReplaceAll(parts[4], "\\011", "\t")
 
 		filesystems = append(filesystems, filesystemLabels{
 			device:      parts[m+3],

collector/meminfo_darwin.go

@@ -52,7 +52,7 @@ func (c *meminfoCollector) getMemInfo() (map[string]float64, error) {
 		&infoCount,
 	)
 	if ret != C.KERN_SUCCESS {
-		return nil, fmt.Errorf("Couldn't get memory statistics, host_statistics returned %d", ret)
+		return nil, fmt.Errorf("couldn't get memory statistics, host_statistics returned %d", ret)
 	}
 	totalb, err := unix.Sysctl("hw.memsize")
 	if err != nil {

collector/meminfo_linux.go

@@ -44,7 +44,7 @@ func NewMeminfoCollector(logger *slog.Logger) (Collector, error) {
 func (c *meminfoCollector) getMemInfo() (map[string]float64, error) {
 	meminfo, err := c.fs.Meminfo()
 	if err != nil {
-		return nil, fmt.Errorf("Failed to get memory info: %s", err)
+		return nil, fmt.Errorf("failed to get memory info: %s", err)
 	}
 
 	metrics := make(map[string]float64)

collector/perf_linux_test.go

@@ -33,10 +33,10 @@ func canTestPerf(t *testing.T) {
 	if err != nil {
 		t.Skip("Procfs not mounted, skipping perf tests")
 	}
-	paranoidStr := strings.Replace(string(paranoidBytes), "\n", "", -1)
+	paranoidStr := strings.ReplaceAll(string(paranoidBytes), "\n", "")
 	paranoid, err := strconv.Atoi(paranoidStr)
 	if err != nil {
-		t.Fatalf("Expected perf_event_paranoid to be an int, got: %s", paranoidStr)
+		t.Fatalf("expected perf_event_paranoid to be an int, got: %s", paranoidStr)
 	}
 	if paranoid >= 1 {
 		t.Skip("Skipping perf tests, set perf_event_paranoid to 0")

collector/systemd_linux_test.go

@@ -122,11 +122,12 @@ func TestSystemdSummary(t *testing.T) {
 	summary := summarizeUnits(fixtures[0])
 
 	for _, state := range unitStatesName {
-		if state == "inactive" {
+		switch state {
+		case "inactive":
 			testSummaryHelper(t, state, summary[state], 3.0)
-		} else if state == "active" {
+		case "active":
 			testSummaryHelper(t, state, summary[state], 1.0)
-		} else {
+		default:
 			testSummaryHelper(t, state, summary[state], 0.0)
 		}
 	}

collector/zfs_linux.go

@@ -435,5 +435,5 @@ type zfsSysctl string
 
 func (s zfsSysctl) metricName() string {
 	parts := strings.Split(string(s), ".")
-	return strings.Replace(parts[len(parts)-1], "-", "_", -1)
+	return strings.ReplaceAll(parts[len(parts)-1], "-", "_")
 }

node_exporter.go

@@ -112,7 +112,7 @@ func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	if err != nil {
 		h.logger.Warn("Couldn't create filtered metrics handler:", "err", err)
 		w.WriteHeader(http.StatusBadRequest)
-		w.Write([]byte(fmt.Sprintf("Couldn't create filtered metrics handler: %s", err)))
+		fmt.Fprintf(w, "Couldn't create filtered metrics handler: %s", err)
 		return
 	}
 	filteredHandler.ServeHTTP(w, r)