Modifications to httpjson plugin

plugins/httpjson/httpjson_test.go

@@ -0,0 +1,187 @@
+package httpjson
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/influxdb/telegraf/testutil"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+const validJSON = `
+	{
+		"parent": {
+			"child": 3,
+			"ignored_child": "hi"
+		},
+		"ignored_null": null,
+		"integer": 4,
+		"ignored_list": [3, 4],
+		"ignored_parent": {
+			"another_ignored_list": [4],
+			"another_ignored_null": null,
+			"ignored_string": "hello, world!"
+		}
+	}`
+
+const invalidJSON = "I don't think this is JSON"
+
+const empty = ""
+
+type mockHTTPClient struct {
+	responseBody string
+	statusCode   int
+}
+
+// Mock implementation of MakeRequest. Usually returns an http.Response with
+// hard-coded responseBody and statusCode. However, if the request uses a
+// nonstandard method, it uses status code 405 (method not allowed)
+func (c mockHTTPClient) MakeRequest(req *http.Request) (*http.Response, error) {
+	resp := http.Response{}
+	resp.StatusCode = c.statusCode
+
+	// basic error checking on request method
+	allowedMethods := []string{"GET", "HEAD", "POST", "PUT", "DELETE", "TRACE", "CONNECT"}
+	methodValid := false
+	for _, method := range allowedMethods {
+		if req.Method == method {
+			methodValid = true
+			break
+		}
+	}
+
+	if !methodValid {
+		resp.StatusCode = 405 // Method not allowed
+	}
+
+	resp.Body = ioutil.NopCloser(strings.NewReader(c.responseBody))
+	return &resp, nil
+}
+
+// Generates a pointer to an HttpJson object that uses a mock HTTP client.
+// Parameters:
+//     response  : Body of the response that the mock HTTP client should return
+//     statusCode: HTTP status code the mock HTTP client should return
+//
+// Returns:
+//     *HttpJson: Pointer to an HttpJson object that uses the generated mock HTTP client
+func genMockHttpJson(response string, statusCode int) *HttpJson {
+	return &HttpJson{
+		client: mockHTTPClient{responseBody: response, statusCode: statusCode},
+		Services: []Service{
+			Service{
+				Servers: []string{
+					"http://server1.example.com/metrics/",
+					"http://server2.example.com/metrics/",
+				},
+				Name:   "my_webapp",
+				Method: "GET",
+				Parameters: map[string]string{
+					"httpParam1": "12",
+					"httpParam2": "the second parameter",
+				},
+			},
+			Service{
+				Servers: []string{
+					"http://server1.example.com/metrics/",
+					"http://server2.example.com/metrics/",
+				},
+				Name:   "other_webapp",
+				Method: "POST",
+				Parameters: map[string]string{
+					"httpParam1": "12",
+					"httpParam2": "the second parameter",
+				},
+			},
+		},
+	}
+}
+
+// Test that the proper values are ignored or collected
+func TestHttpJson200(t *testing.T) {
+	httpjson := genMockHttpJson(validJSON, 200)
+
+	var acc testutil.Accumulator
+	err := httpjson.Gather(&acc)
+	require.NoError(t, err)
+
+	assert.Equal(t, 8, len(acc.Points))
+
+	for _, service := range httpjson.Services {
+		for _, srv := range service.Servers {
+			require.NoError(t,
+				acc.ValidateTaggedValue(
+					fmt.Sprintf("%s_parent_child", service.Name),
+					3.0,
+					map[string]string{"server": srv},
+				),
+			)
+			require.NoError(t,
+				acc.ValidateTaggedValue(
+					fmt.Sprintf("%s_integer", service.Name),
+					4.0,
+					map[string]string{"server": srv},
+				),
+			)
+		}
+	}
+}
+
+// Test response to HTTP 500
+func TestHttpJson500(t *testing.T) {
+	httpjson := genMockHttpJson(validJSON, 500)
+
+	var acc testutil.Accumulator
+	err := httpjson.Gather(&acc)
+
+	assert.NotNil(t, err)
+	// 4 error lines for (2 urls) * (2 services)
+	assert.Equal(t, len(strings.Split(err.Error(), "\n")), 4)
+	assert.Equal(t, 0, len(acc.Points))
+}
+
+// Test response to HTTP 405
+func TestHttpJsonBadMethod(t *testing.T) {
+	httpjson := genMockHttpJson(validJSON, 200)
+	httpjson.Services[0].Method = "NOT_A_REAL_METHOD"
+
+	var acc testutil.Accumulator
+	err := httpjson.Gather(&acc)
+
+	assert.NotNil(t, err)
+	// 2 error lines for (2 urls) * (1 falied service)
+	assert.Equal(t, len(strings.Split(err.Error(), "\n")), 2)
+
+	// (2 measurements) * (2 servers) * (1 successful service)
+	assert.Equal(t, 4, len(acc.Points))
+}
+
+// Test response to malformed JSON
+func TestHttpJsonBadJson(t *testing.T) {
+	httpjson := genMockHttpJson(invalidJSON, 200)
+
+	var acc testutil.Accumulator
+	err := httpjson.Gather(&acc)
+
+	assert.NotNil(t, err)
+	// 4 error lines for (2 urls) * (2 services)
+	assert.Equal(t, len(strings.Split(err.Error(), "\n")), 4)
+	assert.Equal(t, 0, len(acc.Points))
+}
+
+// Test response to empty string as response objectgT
+func TestHttpJsonEmptyResponse(t *testing.T) {
+	httpjson := genMockHttpJson(empty, 200)
+
+	var acc testutil.Accumulator
+	err := httpjson.Gather(&acc)
+
+	assert.NotNil(t, err)
+	// 4 error lines for (2 urls) * (2 services)
+	assert.Equal(t, len(strings.Split(err.Error(), "\n")), 4)
+	assert.Equal(t, 0, len(acc.Points))
+}