Add -local_only flag to get local node metrics per node

src/client.go

@@ -12,7 +12,9 @@ import (
 
 const (
 	nodeStatsEndpoint          = "/_nodes/stats"
+	localNodeStatsEndpoint     = "/_nodes/_local/stats"
 	localNodeInventoryEndpoint = "/_nodes/_local"
+	localNodeIdEndpoint        = "/_nodes/_local/id"
 	commonStatsEndpoint        = "/_stats"
 	clusterEndpoint            = "/_cluster/health"
 	indicesStatsEndpoint       = "/_cat/indices?format=json"

src/elasticsearch.go

@@ -31,6 +31,7 @@ type argumentList struct {
 	IndicesRegex           string `default:"" help:"A regex pattern that matches the index names to collect. Collects all if unspecified"`
 	ShowVersion            bool   `default:"false" help:"Print build information and exit"`
 	MasterOnly             bool   `default:"false" help:"Collect cluster metrics on the elected master only"`
+	LocalOnly              bool   `default:"false" help:"Collect node metrics on the local node only"`
 	TLSInsecureSkipVerify  bool   `default:"false" help:"Enabled TLS insecure skip verify"`
 }
 
@@ -61,6 +62,9 @@ func main() {
 			buildDate)
 		os.Exit(0)
 	}
+	if args.MasterOnly && args.LocalOnly {
+		logErrorAndExit(fmt.Errorf("Select argument -master_only or -local_only, not both"))
+	}
 
 	// Create a client for metrics
 	metricsClient, err := NewClient(args.Hostname)

src/inventory_definition.go

@@ -2,7 +2,8 @@ package main
 
 // LocalNodeResponse struct (/_nodes/_local endpoint)
 type LocalNodeResponse struct {
-	Nodes map[string]*LocalNode `json:"nodes"`
+	ClusterName string                `json:"cluster_name"`
+	Nodes       map[string]*LocalNode `json:"nodes"`
 }
 
 // LocalNode is the node API object

src/metrics.go

@@ -18,34 +18,41 @@ var (
 
 // populateMetrics wrapper to call each of the individual populate functions
 func populateMetrics(i *integration.Integration, client Client, env string) {
-	if args.MasterOnly {
-		nodeID, err := getLocalNodeID(client)
+	nodeID, clusterName, err := getLocalNodeID(client)
+	if err != nil {
+		log.Error("There was an error gathering the host node ID: %v", err)
+		return
+	}
+
+	if args.LocalOnly {
+		err = populateNodesMetrics(i, client, clusterName, localNodeStatsEndpoint)
 		if err != nil {
-			log.Error("There was an error gathering the host node ID: %v", err)
-			return
+			log.Error("There was an error populating metrics for local node: %v", err)
 		}
-		masterID, err := getMasterNodeID(client)
-		if err != nil {
-			log.Error("There was an error gathering the elected master node ID: %v", err)
-			return
-		}
-		if nodeID != masterID {
+		if !getClusterNeeded(client, nodeID) {
 			log.Info("The host is not the elected master, cluster metrics will be skipped")
 			return
 		}
 		log.Info("The host is the elected master, cluster metrics will be collected")
+	} else {
+		if args.MasterOnly {
+			if !getClusterNeeded(client, nodeID) {
+				log.Info("The host is not the elected master, node/cluster metrics will be skipped")
+				return
+			}
+			log.Info("The host is the elected master, node/cluster metrics will be collected")
+		}
+		err = populateNodesMetrics(i, client, clusterName, nodeStatsEndpoint)
+		if err != nil {
+			log.Error("There was an error populating metrics for nodes: %v", err)
+		}
 	}
 
-	clusterName, err := populateClusterMetrics(i, client, env)
+	_, err = populateClusterMetrics(i, client, env)
 	if err != nil {
 		log.Error("There was an error populating metrics for clusters: %v", err)
 	}
 
-	err = populateNodesMetrics(i, client, clusterName)
-	if err != nil {
-		log.Error("There was an error populating metrics for nodes: %v", err)
-	}
-
 	// we want to use the response from common to populate some index-specific stats.
 	commonResponse, err := populateCommonMetrics(i, client, clusterName)
 	if err != nil {
@@ -60,23 +67,38 @@ func populateMetrics(i *integration.Integration, client Client, env string) {
 	}
 }
 
-func getLocalNodeID(client Client) (nodeId string, err error) {
+// getClusterNeeded determines if cluster and common metrics should be scraped
+func getClusterNeeded(client Client, nodeID string) (needed bool) {
+	if args.MasterOnly || args.LocalOnly {
+		masterID, err := getMasterNodeID(client)
+		if err != nil {
+			log.Error("There was an error gathering the elected master node ID: %v", err)
+			return
+		}
+		needed = nodeID == masterID
+	} else {
+		needed = true
+	}
+	return
+}
+
+func getLocalNodeID(client Client) (nodeId, clusterName string, err error) {
 	var nodeResponseObject LocalNodeResponse
-	err = client.Request(localNodeInventoryEndpoint, &nodeResponseObject)
+	err = client.Request(localNodeIdEndpoint, &nodeResponseObject)
 	if err != nil {
-		return "", err
+		return "", "", err
 	}
 	return parseLocalNodeID(nodeResponseObject)
 }
 
-func parseLocalNodeID(nodeStats LocalNodeResponse) (string, error) {
+func parseLocalNodeID(nodeStats LocalNodeResponse) (nodeId, clusterName string, err error) {
 	nodes := nodeStats.Nodes
 	if len(nodes) == 1 {
 		for k := range nodes {
-			return k, nil
+			return k, nodeStats.ClusterName, nil
 		}
 	}
-	return "", errLocalNodeID
+	return "", "", errLocalNodeID
 }
 
 func getMasterNodeID(client Client) (masterId string, err error) {
@@ -91,10 +113,10 @@ func getMasterNodeID(client Client) (masterId string, err error) {
 	return masterIdResponseObject[0].ID, nil
 }
 
-func populateNodesMetrics(i *integration.Integration, client Client, clusterName string) error {
+func populateNodesMetrics(i *integration.Integration, client Client, clusterName, endpoint string) error {
 	log.Info("Collecting node metrics")
 	nodeResponse := new(NodeResponse)
-	err := client.Request(nodeStatsEndpoint, &nodeResponse)
+	err := client.Request(endpoint, &nodeResponse)
 	if err != nil {
 		return err
 	}

src/metrics_test.go

@@ -58,7 +58,7 @@ func TestGetLocalNodeID(t *testing.T) {
 	mockedReturnVal := filepath.Join("testdata", "good-nodes-local.json")
 	fakeClient.On("Request", localNodeInventoryEndpoint).Return(mockedReturnVal, nil).Once()
 
-	nodeID, err := getLocalNodeID(&fakeClient)
+	nodeID, _, err := getLocalNodeID(&fakeClient)
 	assert.NoError(t, err)
 	assert.Equal(t, "z9ZPp87vT92qG1cRVRIcMQ", nodeID)
 }
@@ -68,7 +68,7 @@ func TestGetLocalNodeID_Error(t *testing.T) {
 	mockedReturnVal := filepath.Join("testdata", "bad-nodes-local.json")
 	fakeClient.On("Request", localNodeInventoryEndpoint).Return(mockedReturnVal, nil).Once()
 
-	_, err := getLocalNodeID(&fakeClient)
+	_, _, err := getLocalNodeID(&fakeClient)
 	assert.Error(t, err)
 	assert.Equal(t, errLocalNodeID, err)
 }
@@ -97,7 +97,7 @@ func TestPopulateNodesMetrics(t *testing.T) {
 	client := createNewTestClient()
 	client.init("nodeStatsMetricsResult.json", nodeStatsEndpoint, t)
 
-	err := populateNodesMetrics(i, client, testClusterName)
+	err := populateNodesMetrics(i, client, testClusterName, nodeStatsEndpoint)
 	assert.NoError(t, err)
 
 	sourceFile := filepath.Join("testdata", "nodeStatsMetricsResult.json")
@@ -118,7 +118,7 @@ func TestPopulateNodesMetrics_Error(t *testing.T) {
 	mockClient.ReturnRequestError = true
 
 	i := getTestingIntegration(t)
-	err := populateNodesMetrics(i, mockClient, testClusterName)
+	err := populateNodesMetrics(i, mockClient, testClusterName, nodeStatsEndpoint)
 	assert.Error(t, err, "should be an error")
 }