minor fix + add golangci-lint

.github/workflows/golang-lint.yml

@@ -0,0 +1,21 @@
+name: golangci-lint
+on:
+  push:
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  golangci:
+    name: lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: stable
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v6
+        with:
+          version: v1.60

.github/workflows/tests.yml

@@ -2,6 +2,7 @@ name: tests
 
 on:
   push:
+  pull_request:
 
 jobs:
   run-tests:

pkg/scraping/provider/filesystemusage.go

@@ -41,9 +41,12 @@ func NewProviderFileSystemUsage(params map[string]any, scrapeInterval time.Durat
 		}
 	})
 	cfg, err := configmapper.MapOnStructWithContext[ProviderFileSystemUsage](&mapperCtx, params)
+	if err != nil {
+		return nil, err
+	}
 	cfg.mountPointStats = make(map[string]*stats.WindowCollector[uint64])
 	if cfg.RateThresholdWindow < scrapeInterval {
-		return nil, fmt.Errorf("rate_threshold must be greater than or equal to scrape_interval")
+		return nil, fmt.Errorf("rate_threshold_window must be greater than or equal to scrape_interval (%v < %v)", cfg.RateThresholdWindow, scrapeInterval)
 	}
 	return &cfg, err
 }