Implementing review feedback

plugins/inputs/ssl_cert/ssl_cert.go

@@ -24,24 +24,28 @@ const sampleConfig = `
 `
 const description = "Reads metrics from a SSL certificate"
 
+// SSLCert holds the configuration of the plugin.
 type SSLCert struct {
 	Servers []string      `toml:"servers"`
 	Files   []string      `toml:"files"`
 	Timeout time.Duration `toml:"timeout"`
 
 	// For tests
-	CloseConn bool
+	CloseConn  bool
+	UnsetCerts bool
 }
 
+// Description returns description of the plugin.
 func (sc *SSLCert) Description() string {
 	return description
 }
 
+// SampleConfig returns configuration sample for the plugin.
 func (sc *SSLCert) SampleConfig() string {
 	return sampleConfig
 }
 
-func getRemoteCert(server string, timeout time.Duration, closeConn bool) (*x509.Certificate, error) {
+func getRemoteCert(server string, timeout time.Duration, closeConn bool, unsetCerts bool) (*x509.Certificate, error) {
 	tlsCfg := &tls.Config{
 		InsecureSkipVerify: true,
 	}
@@ -66,8 +70,12 @@ func getRemoteCert(server string, timeout time.Duration, closeConn bool) (*x509.
 
 	certs := conn.ConnectionState().PeerCertificates
 
+	if unsetCerts {
+		certs = nil
+	}
+
 	if certs == nil || len(certs) < 1 {
-		return nil, errors.New("Couldn't get remote certificate.")
+		return nil, errors.New("couldn't get remote certificate")
 	}
 
 	return certs[0], nil
@@ -81,7 +89,7 @@ func getLocalCert(filename string) (*x509.Certificate, error) {
 
 	block, _ := pem.Decode(content)
 	if block == nil {
-		return nil, errors.New("Failed to parse certificate PEM.")
+		return nil, errors.New("failed to parse certificate PEM")
 	}
 
 	cert, err := x509.ParseCertificate(block.Bytes)
@@ -108,13 +116,14 @@ func getMetrics(cert *x509.Certificate, now time.Time) map[string]interface{} {
 	return metrics
 }
 
+// Gather adds metrics into the accumulator.
 func (sc *SSLCert) Gather(acc telegraf.Accumulator) error {
 	now := time.Now()
 
 	for _, server := range sc.Servers {
-		cert, err := getRemoteCert(server, sc.Timeout*time.Second, sc.CloseConn)
+		cert, err := getRemoteCert(server, sc.Timeout*time.Second, sc.CloseConn, sc.UnsetCerts)
 		if err != nil {
-			return errors.New(fmt.Sprintf("Cannot get remote SSL cert: %s", err))
+			return fmt.Errorf("cannot get remote SSL cert '%s': %s", server, err)
 		}
 
 		tags := map[string]string{
@@ -129,7 +138,7 @@ func (sc *SSLCert) Gather(acc telegraf.Accumulator) error {
 	for _, file := range sc.Files {
 		cert, err := getLocalCert(file)
 		if err != nil {
-			return errors.New(fmt.Sprintf("Cannot get local SSL cert: %s", err))
+			return fmt.Errorf("cannot get local SSL cert '%s': %s", file, err)
 		}
 
 		tags := map[string]string{

plugins/inputs/ssl_cert/ssl_cert_test.go

@@ -9,6 +9,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/testutil"
 )
 
@@ -64,9 +65,8 @@ JoiUjTAZegW1RkST3tB1an9zO0EcPvo/1yU7wKaMuNwmauPlltBdpaTwojeUBiFr
 AoQUXWIiFBoFfpNVcvUgHyGGc1hv7TX8Eh8KGo2+VuPzxnFuRrbbYCs=
 -----END RSA PRIVATE KEY-----`
 
-func getTestPrefix(testN int) string {
-	return fmt.Sprintf("Test [%d]: ", testN)
-}
+// Make sure SSLCert implements telegraf.Input
+var _ telegraf.Input = &SSLCert{}
 
 func TestGatherRemote(t *testing.T) {
 	if testing.Short() {
@@ -77,51 +77,54 @@ func TestGatherRemote(t *testing.T) {
 		server  string
 		timeout time.Duration
 		close   bool
+		unset   bool
 		error   bool
 	}{
-		{server: ":99999", timeout: 0, close: false, error: true},
-		{server: "", timeout: 5, close: false, error: false},
-		{server: "", timeout: 0, close: true, error: true},
-	}
-
-	pair, err := tls.X509KeyPair([]byte(testCert), []byte(testKey))
-	if err != nil {
-		t.Error(err)
+		{server: ":99999", timeout: 0, close: false, unset: false, error: true},
+		{server: "", timeout: 5, close: false, unset: false, error: false},
+		{server: "", timeout: 5, close: false, unset: true, error: true},
+		{server: "", timeout: 0, close: true, unset: false, error: true},
 	}
 
-	config := &tls.Config{
-		Certificates: []tls.Certificate{pair},
-	}
+	for i, test := range tests {
+		pair, err := tls.X509KeyPair([]byte(testCert), []byte(testKey))
+		if err != nil {
+			t.Fatal(err)
+		}
 
-	ln, err := tls.Listen("tcp", ":0", config)
-	if err != nil {
-		t.Error(err)
-	}
-	defer ln.Close()
+		config := &tls.Config{
+			Certificates: []tls.Certificate{pair},
+		}
 
-	go func() {
-		sconn, err := ln.Accept()
+		ln, err := tls.Listen("tcp", ":0", config)
 		if err != nil {
-			return
+			t.Fatal(err)
 		}
+		defer ln.Close()
 
-		serverConfig := config.Clone()
+		go func() {
+			sconn, err := ln.Accept()
+			if err != nil {
+				return
+			}
 
-		srv := tls.Server(sconn, serverConfig)
-		if err := srv.Handshake(); err != nil {
-			return
-		}
-	}()
+			serverConfig := config.Clone()
+
+			srv := tls.Server(sconn, serverConfig)
+			if err := srv.Handshake(); err != nil {
+				return
+			}
+		}()
 
-	for i, test := range tests {
 		if test.server == "" {
 			test.server = ln.Addr().String()
 		}
 
 		sc := SSLCert{
-			Servers:   []string{test.server},
-			Timeout:   test.timeout,
-			CloseConn: test.close,
+			Servers:    []string{test.server},
+			Timeout:    test.timeout,
+			CloseConn:  test.close,
+			UnsetCerts: test.unset,
 		}
 
 		error := false
@@ -155,22 +158,22 @@ func TestGatherLocal(t *testing.T) {
 	for i, test := range tests {
 		f, err := ioutil.TempFile("", "ssl_cert")
 		if err != nil {
-			t.Error(err)
+			t.Fatal(err)
 		}
 
 		_, err = f.Write([]byte(test.content))
 		if err != nil {
-			t.Error(err)
+			t.Fatal(err)
 		}
 
 		err = f.Chmod(test.mode)
 		if err != nil {
-			t.Error(err)
+			t.Fatal(err)
 		}
 
 		err = f.Close()
 		if err != nil {
-			t.Error(err)
+			t.Fatal(err)
 		}
 
 		defer os.Remove(f.Name())