package main import ( "fmt" "io/ioutil" "net/http" "os" "os/exec" "path/filepath" "testing" "time" "github.com/prometheus/procfs" ) const ( binary = "./node_exporter" address = "localhost:19100" ) func TestFileDescriptorLeak(t *testing.T) { if _, err := os.Stat(binary); err != nil { t.Skipf("node_exporter binary not available, try to run `make build` first: %s", err) } if _, err := procfs.NewStat(); err != nil { t.Skipf("proc filesystem is not available, but currently required to read number of open file descriptors: %s", err) } exporter := exec.Command(binary, "-web.listen-address", address) test := func(pid int) error { if err := queryExporter(address); err != nil { return err } proc, err := procfs.NewProc(pid) if err != nil { return err } fdsBefore, err := proc.FileDescriptors() if err != nil { return err } for i := 0; i < 5; i++ { if err := queryExporter(address); err != nil { return err } } fdsAfter, err := proc.FileDescriptors() if err != nil { return err } if want, have := len(fdsBefore), len(fdsAfter); want != have { return fmt.Errorf("want %d open file descriptors after metrics scrape, have %d", want, have) } return nil } if err := runCommandAndTests(exporter, test); err != nil { t.Error(err) } } func TestHandlingOfDuplicatedMetrics(t *testing.T) { if _, err := os.Stat(binary); err != nil { t.Skipf("node_exporter binary not available, try to run `make build` first: %s", err) } dir, err := ioutil.TempDir("", "node-exporter") if err != nil { t.Fatal(err) } defer os.RemoveAll(dir) content := []byte("dummy_metric 1\n") if err := ioutil.WriteFile(filepath.Join(dir, "a.prom"), content, 0600); err != nil { t.Fatal(err) } if err := ioutil.WriteFile(filepath.Join(dir, "b.prom"), content, 0600); err != nil { t.Fatal(err) } exporter := exec.Command(binary, "-web.listen-address", address, "-collector.textfile.directory", dir) test := func(_ int) error { return queryExporter(address) } if err := runCommandAndTests(exporter, test); err != nil { t.Error(err) } } func queryExporter(address string) error { resp, err := http.Get(fmt.Sprintf("http://%s/metrics", address)) if err != nil { return err } b, err := ioutil.ReadAll(resp.Body) if err != nil { return err } if err := resp.Body.Close(); err != nil { return err } if want, have := http.StatusOK, resp.StatusCode; want != have { return fmt.Errorf("want /metrics status code %d, have %d. Body:\n%s", want, have, b) } return nil } func runCommandAndTests(cmd *exec.Cmd, fn func(pid int) error) error { if err := cmd.Start(); err != nil { return fmt.Errorf("failed to start command: %s", err) } errc := make(chan error) go func() { if err := cmd.Wait(); err != nil { errc <- fmt.Errorf("execution of command failed: %s", err) } else { errc <- nil } }() // Allow the process to start before running any tests. select { case err := <-errc: return err case <-time.After(100 * time.Millisecond): } go func(pid int) { errc <- fn(pid) }(cmd.Process.Pid) select { case err := <-errc: if cmd.Process != nil { cmd.Process.Kill() } if err != nil { return err } } return nil }