Fix golang-ci linter errors (#10128)

* Fix golang-ci linter errors

Signed-off-by: z1cheng <imchench@gmail.com>

* Fix gofmt errors

Signed-off-by: z1cheng <imchench@gmail.com>

* Add nolint comment to defaults.Backend in Configuration

Signed-off-by: z1cheng <imchench@gmail.com>

* Add #nosec comment to rand.New func

Signed-off-by: z1cheng <imchench@gmail.com>

* Fix errcheck warnings

Signed-off-by: z1cheng <imchench@gmail.com>

* Fix gofmt check

Signed-off-by: z1cheng <imchench@gmail.com>

* Fix unit tests and comments

Signed-off-by: z1cheng <imchench@gmail.com>

---------

Signed-off-by: z1cheng <imchench@gmail.com>

internal/ingress/metric/collectors/process_test.go

@@ -48,7 +48,7 @@ func TestProcessCollector(t *testing.T) {
 
 			done := make(chan struct{})
 			go func() {
-				cmd.Wait()
+				cmd.Wait() //nolint:errcheck
 				status := cmd.ProcessState.Sys().(syscall.WaitStatus)
 				if status.Signaled() {
 					t.Logf("Signal: %v", status.Signal())
@@ -69,7 +69,7 @@ func TestProcessCollector(t *testing.T) {
 			defer func() {
 				cm.Stop()
 
-				cmd.Process.Kill()
+				cmd.Process.Kill() //nolint:errcheck
 				<-done
 				close(done)
 			}()

internal/ingress/metric/collectors/socket_test.go

@@ -58,7 +58,9 @@ func TestNewUDPLogListener(t *testing.T) {
 	}()
 
 	conn, _ := net.Dial("unix", tmpFile)
-	conn.Write([]byte("message"))
+	if _, err := conn.Write([]byte("message")); err != nil {
+		t.Errorf("unexpected error writing to unix socket: %v", err)
+	}
 	conn.Close()
 
 	time.Sleep(1 * time.Millisecond)