Fix some errcheck errors (#2881)

* Check testbed errors

* Check some more errors

* Empty commit to retrigger CI

* Address comments on hostmetricsreceiver

* Rewrite some errchecking code

* Inline ifs

* Inline ifs and change log.Fatalf + Error() calls by log.Fatal

Author: mx-psi

component/componenttest/shutdown_verifier.go

@@ -50,7 +50,7 @@ func verifyTracesProcessorDoesntProduceAfterShutdown(t *testing.T, factory compo
 	// Send some traces to the processor.
 	const generatedCount = 10
 	for i := 0; i < generatedCount; i++ {
-		processor.ConsumeTraces(context.Background(), testdata.GenerateTraceDataOneSpan())
+		require.NoError(t, processor.ConsumeTraces(context.Background(), testdata.GenerateTraceDataOneSpan()))
 	}
 
 	// Now shutdown the processor.

exporter/otlphttpexporter/otlp.go

@@ -126,7 +126,7 @@ func (e *exporter) export(ctx context.Context, url string, request []byte) error
 
 	defer func() {
 		// Discard any remaining response body when we are done reading.
-		io.CopyN(ioutil.Discard, resp.Body, maxHTTPResponseReadBytes)
+		io.CopyN(ioutil.Discard, resp.Body, maxHTTPResponseReadBytes) // nolint:errcheck
 		resp.Body.Close()
 	}()
 

processor/processorhelper/hasher.go

@@ -61,7 +61,7 @@ func sha1Hasher(attr pdata.AttributeValue) {
 	if len(val) > 0 {
 		// #nosec
 		h := sha1.New()
-		h.Write(val)
+		h.Write(val) // nolint: errcheck
 		val = h.Sum(nil)
 		hashedBytes := make([]byte, hex.EncodedLen(len(val)))
 		hex.Encode(hashedBytes, val)

receiver/hostmetricsreceiver/internal/scraper/processesscraper/processes_scraper_unix.go

@@ -40,7 +40,9 @@ func appendSystemSpecificProcessesMetrics(metrics pdata.MetricSlice, startIndex
 
 	metrics.Resize(startIndex + unixMetricsLen)
 	initializeProcessesCountMetric(metrics.At(startIndex+0), now, misc)
-	appendUnixSystemSpecificProcessesMetrics(metrics, startIndex+1, now, misc)
+	if err = appendUnixSystemSpecificProcessesMetrics(metrics, startIndex+1, now, misc); err != nil {
+		return err
+	}
 	return nil
 }
 

receiver/kafkareceiver/kafka_receiver.go

@@ -109,7 +109,7 @@ func (c *kafkaTracesConsumer) Start(context.Context, component.Host) error {
 		nextConsumer: c.nextConsumer,
 		ready:        make(chan bool),
 	}
-	go c.consumeLoop(ctx, consumerGroup)
+	go c.consumeLoop(ctx, consumerGroup) // nolint:errcheck
 	<-consumerGroup.ready
 	return nil
 }

receiver/otlpreceiver/otlphttp.go

@@ -72,5 +72,5 @@ func errorHandler(w http.ResponseWriter, r *http.Request, errMsg string, statusC
 
 	w.Header().Set("Content-Type", contentType)
 	w.WriteHeader(statusCode)
-	w.Write(msg)
+	w.Write(msg) // nolint:errcheck
 }

receiver/zipkinreceiver/trace_receiver.go

@@ -250,7 +250,7 @@ func (zr *ZipkinReceiver) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	if consumerErr != nil {
 		// Transient error, due to some internal condition.
 		w.WriteHeader(http.StatusInternalServerError)
-		w.Write(errNextConsumerRespBody)
+		w.Write(errNextConsumerRespBody) // nolint:errcheck
 		return
 	}
 

service/zpages.go

@@ -40,7 +40,7 @@ func (srv *service) RegisterZPages(mux *http.ServeMux, pathPrefix string) {
 }
 
 func (srv *service) handleServicezRequest(w http.ResponseWriter, r *http.Request) {
-	r.ParseForm()
+	r.ParseForm() // nolint:errcheck
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
 	zpages.WriteHTMLHeader(w, zpages.HeaderData{Title: "service"})
 	zpages.WriteHTMLComponentHeader(w, zpages.ComponentHeaderData{
@@ -58,7 +58,7 @@ func (srv *service) handleServicezRequest(w http.ResponseWriter, r *http.Request
 }
 
 func (srv *service) handlePipelinezRequest(w http.ResponseWriter, r *http.Request) {
-	r.ParseForm()
+	r.ParseForm() // nolint:errcheck
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
 	pipelineName := r.Form.Get(zPipelineName)
 	componentName := r.Form.Get(zComponentName)
@@ -116,7 +116,7 @@ func (srv *service) getPipelinesSummaryTableData() zpages.SummaryPipelinesTableD
 }
 
 func handleExtensionzRequest(host component.Host, w http.ResponseWriter, r *http.Request) {
-	r.ParseForm()
+	r.ParseForm() // nolint:errcheck
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
 	extensionName := r.Form.Get(zExtensionName)
 	zpages.WriteHTMLHeader(w, zpages.HeaderData{Title: "Extensions"})

testbed/testbed/child_process.go

@@ -375,7 +375,9 @@ func (cp *ChildProcess) WatchResourceConsumption() error {
 			cp.fetchCPUUsage()
 
 			if err := cp.checkAllowedResourceUsage(); err != nil {
-				cp.Stop()
+				if _, errStop := cp.Stop(); errStop != nil {
+					log.Printf("Failed to stop child process: %v", err)
+				}
 				return err
 			}
 

testbed/testbed/mock_backend.go

@@ -100,8 +100,9 @@ func (mb *MockBackend) Stop() {
 		log.Printf("Stopping mock backend...")
 
 		mb.logFile.Close()
-		mb.receiver.Stop()
-
+		if err := mb.receiver.Stop(); err != nil {
+			log.Printf("Failed to stop receiver: %v", err)
+		}
 		// Print stats.
 		log.Printf("Stopped backend. %s", mb.GetStats())
 	})