Improve monit http client transport mock (#6955)

plugins/inputs/monit/monit.go

@@ -175,38 +175,15 @@ type Monit struct {
 	Address  string `toml:"address"`
 	Username string `toml:"username"`
 	Password string `toml:"password"`
-	client   HTTPClient
+	client   http.Client
 	tls.ClientConfig
 	Timeout internal.Duration `toml:"timeout"`
 }
 
-type HTTPClient interface {
-	MakeRequest(req *http.Request) (*http.Response, error)
-
-	SetHTTPClient(client *http.Client)
-	HTTPClient() *http.Client
-}
-
 type Messagebody struct {
 	Metrics []string `json:"metrics"`
 }
 
-type RealHTTPClient struct {
-	client *http.Client
-}
-
-func (c *RealHTTPClient) MakeRequest(req *http.Request) (*http.Response, error) {
-	return c.client.Do(req)
-}
-
-func (c *RealHTTPClient) SetHTTPClient(client *http.Client) {
-	c.client = client
-}
-
-func (c *RealHTTPClient) HTTPClient() *http.Client {
-	return c.client
-}
-
 func (m *Monit) Description() string {
 	return "Read metrics and status information about processes managed by Monit"
 }
@@ -240,14 +217,13 @@ func (m *Monit) Init() error {
 		return err
 	}
 
-	client := &http.Client{
+	m.client = http.Client{
 		Transport: &http.Transport{
 			TLSClientConfig: tlsCfg,
 			Proxy:           http.ProxyFromEnvironment,
 		},
 		Timeout: m.Timeout.Duration,
 	}
-	m.client.SetHTTPClient(client)
 	return nil
 }
 
@@ -261,7 +237,7 @@ func (m *Monit) Gather(acc telegraf.Accumulator) error {
 		req.SetBasicAuth(m.Username, m.Password)
 	}
 
-	resp, err := m.client.MakeRequest(req)
+	resp, err := m.client.Do(req)
 	if err != nil {
 		return err
 	}
@@ -428,8 +404,6 @@ func monitoringStatus(s Service) string {
 
 func init() {
 	inputs.Add("monit", func() telegraf.Input {
-		return &Monit{
+		return &Monit{}
-			client: &RealHTTPClient{},
-		}
 	})
 }

plugins/inputs/monit/monit_test.go

@@ -13,19 +13,14 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-type MockHTTPClient struct {
+type transportMock struct {
-	networkError string
 }
 
-func (c *MockHTTPClient) MakeRequest(req *http.Request) (*http.Response, error) {
+func (t *transportMock) RoundTrip(r *http.Request) (*http.Response, error) {
-	return nil, errors.New(c.networkError)
+	errorString := "Get http://127.0.0.1:2812/_status?format=xml: " +
-}
+		"read tcp 192.168.10.2:55610->127.0.0.1:2812: " +
-
+		"read: connection reset by peer"
-func (c *MockHTTPClient) SetHTTPClient(client *http.Client) {
+	return nil, errors.New(errorString)
-}
-
-func (c *MockHTTPClient) HTTPClient() *http.Client {
-	return nil
 }
 
 func TestServiceType(t *testing.T) {
@@ -336,7 +331,6 @@ func TestServiceType(t *testing.T) {
 
 			plugin := &Monit{
 				Address: ts.URL,
-				client:  &RealHTTPClient{},
 			}
 
 			plugin.Init()
@@ -536,7 +530,6 @@ func TestMonitFailure(t *testing.T) {
 
 			plugin := &Monit{
 				Address: ts.URL,
-				client:  &RealHTTPClient{},
 			}
 
 			plugin.Init()
@@ -561,19 +554,15 @@ func checkAuth(r *http.Request, username, password string) bool {
 
 func TestAllowHosts(t *testing.T) {
 
-	networkError := "Get http://127.0.0.1:2812/_status?format=xml: " +
-		"read tcp 192.168.10.2:55610->127.0.0.1:2812: " +
-		"read: connection reset by peer"
 	r := &Monit{
 		Address:  "http://127.0.0.1:2812",
 		Username: "test",
 		Password: "test",
-		client:   &MockHTTPClient{networkError},
 	}
 
 	var acc testutil.Accumulator
 
-	r.Init()
+	r.client.Transport = &transportMock{}
 
 	err := r.Gather(&acc)
 
@@ -588,7 +577,6 @@ func TestConnection(t *testing.T) {
 		Address:  "http://127.0.0.1:2812",
 		Username: "test",
 		Password: "test",
-		client:   &RealHTTPClient{},
 	}
 
 	var acc testutil.Accumulator
@@ -625,7 +613,6 @@ func TestInvalidUsernameorPassword(t *testing.T) {
 		Address:  ts.URL,
 		Username: "test",
 		Password: "test",
-		client:   &RealHTTPClient{},
 	}
 
 	var acc testutil.Accumulator
@@ -658,7 +645,6 @@ func TestNoUsernameorPasswordConfiguration(t *testing.T) {
 
 	r := &Monit{
 		Address: ts.URL,
-		client:  &RealHTTPClient{},
 	}
 
 	var acc testutil.Accumulator
@@ -703,7 +689,6 @@ func TestInvalidXMLAndInvalidTypes(t *testing.T) {
 
 			plugin := &Monit{
 				Address: ts.URL,
-				client:  &RealHTTPClient{},
 			}
 
 			plugin.Init()