Migrate golangci-lint to v2

* Migrate golangci-lint config to v2.
* Fixup linting issues.

Signed-off-by: SuperQ <[email protected]>

Author: SuperQ

.golangci.yml

@@ -1,13 +1,9 @@
----
+version: "2"
 linters:
   enable:
-  - sloglint
-
-run:
-  timeout: 5m
-
-issues:
-  exclude-rules:
-    - path: _test.go
-      linters:
-        - errcheck
+    - sloglint
+  exclusions:
+    rules:
+      - linters:
+          - errcheck
+        path: _test.go

collectors/monitoring_collector.go

@@ -424,7 +424,7 @@ func (c *MonitoringCollector) reportTimeSeriesMetrics(
 		for _, point := range timeSeries.Points {
 			endTime, err := time.Parse(time.RFC3339Nano, point.Interval.EndTime)
 			if err != nil {
-				return fmt.Errorf("Error parsing TimeSeries Point interval end time `%s`: %s", point.Interval.EndTime, err)
+				return fmt.Errorf("error parsing TimeSeries Point interval end time `%s`: %s", point.Interval.EndTime, err)
 			}
 			if endTime.After(newestEndTime) {
 				newestEndTime = endTime
@@ -541,7 +541,7 @@ func (c *MonitoringCollector) generateHistogramBuckets(
 			bucketKeys[i] = opts.ExponentialBuckets.Scale * math.Pow(opts.ExponentialBuckets.GrowthFactor, float64(i))
 		}
 	default:
-		return nil, errors.New("Unknown distribution buckets")
+		return nil, errors.New("unknown distribution buckets")
 	}
 	// The last bucket is always infinity
 	// @see https://cloud.google.com/monitoring/api/ref_v3/rest/v3/TypedValue#bucketoptions

stackdriver_exporter.go

@@ -161,7 +161,7 @@ func getDefaultGCPProject(ctx context.Context) (*string, error) {
 func createMonitoringService(ctx context.Context) (*monitoring.Service, error) {
 	googleClient, err := google.DefaultClient(ctx, monitoring.MonitoringReadScope)
 	if err != nil {
-		return nil, fmt.Errorf("Error creating Google client: %v", err)
+		return nil, fmt.Errorf("error creating Google client: %v", err)
 	}
 
 	googleClient.Timeout = *stackdriverHttpTimeout
@@ -175,7 +175,7 @@ func createMonitoringService(ctx context.Context) (*monitoring.Service, error) {
 
 	monitoringService, err := monitoring.NewService(ctx, option.WithHTTPClient(googleClient), option.WithUniverseDomain(*googleUniverseDomain))
 	if err != nil {
-		return nil, fmt.Errorf("Error creating Google Stackdriver Monitoring service: %v", err)
+		return nil, fmt.Errorf("error creating Google Stackdriver Monitoring service: %v", err)
 	}
 
 	return monitoringService, nil