Client auth (#20)

* Add authentication and end-to-end test on client

* Bump version and add entry to changelog

* add toggle for indices and primaries

* add feature description and args

* Added status code and error checking to client

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## 0.1.1 - 2018-09-13
+### Added
+- Implemented client authentication
+- Implemented toggles for primaries and indices 
+- Added status code and error checking to client requests
+
 ## 0.1.0 - 2018-08-28
 ### Added
 - Initial version: Includes Metrics and Inventory data

elasticsearch-config.yml.sample

@@ -13,5 +13,7 @@ instances:
       use_ssl <true or false to use SSL. If true Certificate bundle must be supplied>
       ca_bundle_dir: <directory for certificate authority bundle, must be included if use_ssl is true>
       ca_bundle_file: <file for certificate authority bundle, must be included if use_ssl is true>
+      collect_indices <true or false to collect indices metrics. If true collect indices, else do not>
+      collect_primaries <true or false to collect primaries metrics. If true collect primaries, else do not>
     labels:
       role: elasticsearch

src/client.go

@@ -3,6 +3,7 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"io/ioutil"
 	"net/http"
 	"time"
 
@@ -19,15 +20,27 @@ const (
 
 // HTTPClient represents a single connection to an Elasticsearch host
 type HTTPClient struct {
-	baseURL string
-	client  *http.Client
+	baseURL  string
+	useAuth  bool
+	username string
+	password string
+	client   *http.Client
 }
 
 // Client interface that assists in mocking for tests
 type Client interface {
 	Request(string, interface{}) error
 }
 
+type errorResponse struct {
+	Error *errorBody `json:"error"`
+}
+
+type errorBody struct {
+	Type   *string `json:"type"`
+	Reason *string `json:"reason"`
+}
+
 // NewClient creates a new Elasticsearch http client.
 // The hostnameOverride parameter specifies a hostname that the client should connect to.
 // Passing in an empty string causes the client to use the hostname specified in the command-line args. (default behavior)
@@ -38,7 +51,10 @@ func NewClient(hostnameOverride string) (*HTTPClient, error) {
 	}
 
 	return &HTTPClient{
-		client: httpClient,
+		client:   httpClient,
+		useAuth:  args.Username != "" || args.Password != "",
+		username: args.Username,
+		password: args.Password,
 		baseURL: func() string {
 			protocol := "http"
 			if args.UseSSL {
@@ -58,16 +74,49 @@ func NewClient(hostnameOverride string) (*HTTPClient, error) {
 // Request takes an endpoint, makes a GET request to that endpoint,
 // and parses the response JSON into a map, which it returns.
 func (c *HTTPClient) Request(endpoint string, v interface{}) error {
-	response, err := c.client.Get(c.baseURL + endpoint)
+	request, err := http.NewRequest("GET", c.baseURL+endpoint, nil)
+	if err != nil {
+		return err
+	}
+	if c.useAuth {
+		request.SetBasicAuth(c.username, c.password)
+	}
+
+	response, err := c.client.Do(request)
 	if err != nil {
 		return err
 	}
 	defer checkErr(response.Body.Close)
 
+	err = c.checkStatusCode(response)
+	if err != nil {
+		return err
+	}
+
 	err = json.NewDecoder(response.Body).Decode(v)
 	if err != nil {
 		return err
 	}
 
 	return nil
 }
+
+func (c *HTTPClient) checkStatusCode(response *http.Response) error {
+	if response.StatusCode == 200 {
+		return nil
+	}
+
+	// try parsing error in body, otherwise return generic error
+	responseBytes, err := ioutil.ReadAll(response.Body)
+	if err != nil {
+		return fmt.Errorf("status code %v - could not parse body from response: %v", response.StatusCode, err)
+	}
+
+	var errResponse errorResponse
+	err = json.Unmarshal(responseBytes, &errResponse)
+	if err != nil {
+		return fmt.Errorf("status code %v - could not parse error information from response: %v", response.StatusCode, err)
+	}
+
+	return fmt.Errorf("status code %v - received error of type '%s' from Elasticsearch: %s", response.StatusCode, *errResponse.Error.Type, *errResponse.Error.Reason)
+}

src/client_test.go

@@ -2,6 +2,8 @@ package main
 
 import (
 	"fmt"
+	"net/http"
+	"net/http/httptest"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -66,3 +68,51 @@ func TestBadCertFile(t *testing.T) {
 	_, err := NewClient("")
 	assert.Error(t, err)
 }
+
+func TestAuthRequest(t *testing.T) {
+	// generate a test server so we can capture and inspect the request
+	testServer := httptest.NewServer(http.HandlerFunc(func(res http.ResponseWriter, req *http.Request) {
+		res.WriteHeader(200)
+		username, password, ok := req.BasicAuth()
+		assert.True(t, ok)
+		assert.Equal(t, username, "testUser")
+		assert.Equal(t, password, "testPass")
+		res.Write([]byte("{\"ok\":true}"))
+	}))
+	defer func() { testServer.Close() }()
+
+	client := &HTTPClient{
+		client:   testServer.Client(),
+		useAuth:  true,
+		username: "testUser",
+		password: "testPass",
+		baseURL:  testServer.URL,
+	}
+
+	testResult := struct {
+		OK *bool `json:"ok"`
+	}{}
+
+	err := client.Request("/endpoint", &testResult)
+	assert.NoError(t, err)
+	assert.Equal(t, true, *testResult.OK)
+}
+
+func TestBadStatusCode(t *testing.T) {
+	testServer := httptest.NewServer(http.HandlerFunc(func(res http.ResponseWriter, req *http.Request) {
+		res.WriteHeader(401)
+		res.Write([]byte("{\"error\":{\"type\":\"exception\",\"reason\":\"this is an error\"}}"))
+	}))
+	defer func() { testServer.Close() }()
+
+	client := &HTTPClient{
+		client:   testServer.Client(),
+		useAuth:  true,
+		username: "testUser",
+		password: "testPass",
+		baseURL:  testServer.URL,
+	}
+
+	err := client.Request("/endpoint", nil)
+	assert.Error(t, err)
+}

src/elasticsearch.go

@@ -10,20 +10,22 @@ import (
 
 type argumentList struct {
 	sdkArgs.DefaultArgumentList
-	Hostname     string `default:"localhost" help:"Hostname or IP where Elasticsearch Node is running."`
-	Port         int    `default:"9200" help:"Port on which Elasticsearch Node is listening."`
-	Username     string `default:"" help:"Username for accessing Elasticsearch Node"`
-	Password     string `default:"" help:"Password for the given user."`
-	UseSSL       bool   `default:"false" help:"Signals whether to use SSL or not. Certificate bundle must be supplied"`
-	CABundleFile string `default:"" help:"Alternative Certificate Authority bundle file"`
-	CABundleDir  string `default:"" help:"Alternative Certificate Authority bundle directory"`
-	Timeout      int    `default:"30" help:"Timeout for an API call"`
-	ConfigPath   string `default:"/etc/elasticsearch/elasticsearch.yml" help:"Path to the ElasticSearch configuration .yml file."`
+	Hostname         string `default:"localhost" help:"Hostname or IP where Elasticsearch Node is running."`
+	Port             int    `default:"9200" help:"Port on which Elasticsearch Node is listening."`
+	Username         string `default:"" help:"Username for accessing Elasticsearch Node"`
+	Password         string `default:"" help:"Password for the given user."`
+	UseSSL           bool   `default:"false" help:"Signals whether to use SSL or not. Certificate bundle must be supplied"`
+	CABundleFile     string `default:"" help:"Alternative Certificate Authority bundle file"`
+	CABundleDir      string `default:"" help:"Alternative Certificate Authority bundle directory"`
+	Timeout          int    `default:"30" help:"Timeout for an API call"`
+	ConfigPath       string `default:"/etc/elasticsearch/elasticsearch.yml" help:"Path to the ElasticSearch configuration .yml file."`
+	CollectIndices   bool   `default:"true" help:"Signals whether to collect indices metrics or not"`
+	CollectPrimaries bool   `default:"true" help:"Signals whether to collect primaries metrics or not"`
 }
 
 const (
 	integrationName    = "com.newrelic.elasticsearch"
-	integrationVersion = "0.1.0"
+	integrationVersion = "0.1.1"
 )
 
 var (

src/metrics.go

@@ -27,9 +27,11 @@ func populateMetrics(i *integration.Integration, client Client) {
 		log.Error("There was an error populating metrics for common metrics: %v", err)
 	}
 
-	err = populateIndicesMetrics(i, client, commonResponse)
-	if err != nil {
-		log.Error("There was an error populating metrics for indices: %v", err)
+	if args.CollectIndices {
+		err = populateIndicesMetrics(i, client, commonResponse)
+		if err != nil {
+			log.Error("There was an error populating metrics for indices: %v", err)
+		}
 	}
 }
 
@@ -77,7 +79,11 @@ func populateCommonMetrics(i *integration.Integration, client Client) (*CommonMe
 		return nil, err
 	}
 
-	return commonResponse, setMetricsResponse(i, commonResponse.All, "commonMetrics", "common")
+	if args.CollectPrimaries {
+		err = setMetricsResponse(i, commonResponse.All, "commonMetrics", "common")
+	}
+
+	return commonResponse, err
 }
 
 func populateIndicesMetrics(i *integration.Integration, client Client, commonStats *CommonMetrics) error {

src/metrics_test.go

@@ -115,6 +115,8 @@ func TestPopulateClusterMetrics_Error(t *testing.T) {
 func TestPopulateCommonMetrics(t *testing.T) {
 	i := getTestingIntegration(t)
 	client := createNewTestClient()
+	args.CollectIndices = true
+	args.CollectPrimaries = true
 	client.init("commonMetricsResult.json", commonStatsEndpoint, t)
 
 	populateCommonMetrics(i, client)