add graylog plugin

add unit test for graylog

plugins/inputs/graylog/graylog_test.go

@@ -0,0 +1,199 @@
+package graylog
+
+import (
+	"io/ioutil"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/influxdata/telegraf/testutil"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+const validJSON = `
+  {
+    "total": 3,
+    "metrics": [
+      {
+        "full_name": "jvm.cl.loaded",
+        "metric": {
+          "value": 18910
+        },
+        "name": "loaded",
+        "type": "gauge"
+      },
+      {
+        "full_name": "jvm.memory.pools.Metaspace.committed",
+        "metric": {
+          "value": 108040192
+        },
+        "name": "committed",
+        "type": "gauge"
+      },
+      {
+        "full_name": "org.graylog2.shared.journal.KafkaJournal.writeTime",
+        "metric": {
+          "time": {
+            "min": 99
+          },
+          "rate": {
+            "total": 10,
+            "mean": 2
+          },
+          "duration_unit": "microseconds",
+          "rate_unit": "events/second"
+        },
+        "name": "writeTime",
+        "type": "hdrtimer"
+      }
+    ]
+  }`
+
+var validTags = map[string]map[string]string{
+	"jvm.cl.loaded": {
+		"name":   "loaded",
+		"type":   "gauge",
+		"port":   "12900",
+		"server": "localhost",
+	},
+	"jvm.memory.pools.Metaspace.committed": {
+		"name":   "committed",
+		"type":   "gauge",
+		"port":   "12900",
+		"server": "localhost",
+	},
+	"org.graylog2.shared.journal.KafkaJournal.writeTime": {
+		"name":   "writeTime",
+		"type":   "hdrtimer",
+		"port":   "12900",
+		"server": "localhost",
+	},
+}
+
+var expectedFields = map[string]map[string]interface{}{
+	"jvm.cl.loaded": {
+		"value": float64(18910),
+	},
+	"jvm.memory.pools.Metaspace.committed": {
+		"value": float64(108040192),
+	},
+	"org.graylog2.shared.journal.KafkaJournal.writeTime": {
+		"time_min":   float64(99),
+		"rate_total": float64(10),
+		"rate_mean":  float64(2),
+	},
+}
+
+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
+}
+
+func (c *mockHTTPClient) SetHTTPClient(_ *http.Client) {
+}
+
+func (c *mockHTTPClient) HTTPClient() *http.Client {
+	return 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 genMockGrayLog(response string, statusCode int) []*GrayLog {
+	return []*GrayLog{
+		&GrayLog{
+			client: &mockHTTPClient{responseBody: response, statusCode: statusCode},
+			Servers: []string{
+				"http://localhost:12900/system/metrics/multiple",
+			},
+			Metrics: []string{
+				"jvm.memory.pools.Metaspace.committed",
+				"jvm.cl.loaded",
+				"org.graylog2.shared.journal.KafkaJournal.writeTime",
+			},
+			Username: "test",
+			Password: "test",
+		},
+	}
+}
+
+// Test that the proper values are ignored or collected
+func TestNormalResponse(t *testing.T) {
+	graylog := genMockGrayLog(validJSON, 200)
+
+	for _, service := range graylog {
+		var acc testutil.Accumulator
+		err := service.Gather(&acc)
+		require.NoError(t, err)
+		for k, v := range expectedFields {
+			acc.AssertContainsTaggedFields(t, k, v, validTags[k])
+		}
+	}
+}
+
+// Test response to HTTP 500
+func TestHttpJson500(t *testing.T) {
+	graylog := genMockGrayLog(validJSON, 500)
+
+	var acc testutil.Accumulator
+	err := graylog[0].Gather(&acc)
+
+	assert.NotNil(t, err)
+	assert.Equal(t, 0, acc.NFields())
+}
+
+// Test response to malformed JSON
+func TestHttpJsonBadJson(t *testing.T) {
+	graylog := genMockGrayLog(invalidJSON, 200)
+
+	var acc testutil.Accumulator
+	err := graylog[0].Gather(&acc)
+
+	assert.NotNil(t, err)
+	assert.Equal(t, 0, acc.NFields())
+}
+
+// Test response to empty string as response objectgT
+func TestHttpJsonEmptyResponse(t *testing.T) {
+	graylog := genMockGrayLog(empty, 200)
+
+	var acc testutil.Accumulator
+	err := graylog[0].Gather(&acc)
+
+	assert.NotNil(t, err)
+	assert.Equal(t, 0, acc.NFields())
+}