feat(inputs.kubernetes): Add option to node metric name

The k8s and kube_node plugins produce the same metric name that can
conflict. Provide an option in the k8s plugin to change the name.

fixes: influxdata#9451

plugins/inputs/kubernetes/README.md

@@ -62,6 +62,12 @@ See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
   ## OR
   # bearer_token_string = "abc_123"
 
+  ## Kubernetes Node Metric Name
+  ## The default Kubernetes node metric name (i.e. kubernetes_node) is the same
+  ## for the kubernetes and kube_inventory plugins. To avoid conflicts, set this
+  ## option to a different value.
+  # node_metric_name = "kubernetes_node"
+
   ## Pod labels to be added as tags.  An empty array for both include and
   ## exclude will include all labels.
   # label_include = []

plugins/inputs/kubernetes/kubernetes.go

@@ -29,25 +29,19 @@ var sampleConfig string
 
 // Kubernetes represents the config object for the plugin
 type Kubernetes struct {
-	URL string
-
-	// Bearer Token authorization file path
-	BearerToken       string `toml:"bearer_token"`
-	BearerTokenString string `toml:"bearer_token_string" deprecated:"1.24.0;use 'BearerToken' with a file instead"`
-
-	LabelInclude []string `toml:"label_include"`
-	LabelExclude []string `toml:"label_exclude"`
-
-	labelFilter filter.Filter
-
-	// HTTP Timeout specified as a string - 3s, 1m, 1h
-	ResponseTimeout config.Duration
+	URL               string          `toml:"url"`
+	BearerToken       string          `toml:"bearer_token"`
+	BearerTokenString string          `toml:"bearer_token_string" deprecated:"1.24.0;use 'BearerToken' with a file instead"`
+	NodeMetricName    string          `toml:"node_metric_name"`
+	LabelInclude      []string        `toml:"label_include"`
+	LabelExclude      []string        `toml:"label_exclude"`
+	ResponseTimeout   config.Duration `toml:"response_timeout"`
+	Log               telegraf.Logger `toml:"-"`
 
 	tls.ClientConfig
 
-	Log telegraf.Logger `toml:"-"`
-
-	httpClient *http.Client
+	labelFilter filter.Filter
+	httpClient  *http.Client
 }
 
 const (
@@ -83,6 +77,10 @@ func (k *Kubernetes) Init() error {
 		k.InsecureSkipVerify = true
 	}
 
+	if k.NodeMetricName == "" {
+		k.NodeMetricName = "kubernetes_node"
+	}
+
 	return nil
 }
 
@@ -169,7 +167,7 @@ func (k *Kubernetes) gatherSummary(baseURL string, acc telegraf.Accumulator) err
 		return err
 	}
 	buildSystemContainerMetrics(summaryMetrics, acc)
-	buildNodeMetrics(summaryMetrics, acc)
+	buildNodeMetrics(summaryMetrics, acc, k.NodeMetricName)
 	buildPodMetrics(summaryMetrics, podInfos, k.labelFilter, acc)
 	return nil
 }
@@ -196,7 +194,7 @@ func buildSystemContainerMetrics(summaryMetrics *SummaryMetrics, acc telegraf.Ac
 	}
 }
 
-func buildNodeMetrics(summaryMetrics *SummaryMetrics, acc telegraf.Accumulator) {
+func buildNodeMetrics(summaryMetrics *SummaryMetrics, acc telegraf.Accumulator, metricName string) {
 	tags := map[string]string{
 		"node_name": summaryMetrics.Node.NodeName,
 	}
@@ -219,7 +217,7 @@ func buildNodeMetrics(summaryMetrics *SummaryMetrics, acc telegraf.Accumulator)
 	fields["runtime_image_fs_available_bytes"] = summaryMetrics.Node.Runtime.ImageFileSystem.AvailableBytes
 	fields["runtime_image_fs_capacity_bytes"] = summaryMetrics.Node.Runtime.ImageFileSystem.CapacityBytes
 	fields["runtime_image_fs_used_bytes"] = summaryMetrics.Node.Runtime.ImageFileSystem.UsedBytes
-	acc.AddFields("kubernetes_node", fields, tags)
+	acc.AddFields(metricName, fields, tags)
 }
 
 func (k *Kubernetes) gatherPodInfo(baseURL string) ([]Item, error) {

plugins/inputs/kubernetes/kubernetes_test.go

@@ -2,11 +2,11 @@ package kubernetes
 
 import (
 	"fmt"
-	"github.com/influxdata/telegraf/filter"
 	"net/http"
 	"net/http/httptest"
 	"testing"
 
+	"github.com/influxdata/telegraf/filter"
 	"github.com/influxdata/telegraf/testutil"
 	"github.com/stretchr/testify/require"
 )
@@ -29,8 +29,9 @@ func TestKubernetesStats(t *testing.T) {
 	labelFilter, _ := filter.NewIncludeExcludeFilter([]string{"app", "superkey"}, nil)
 
 	k := &Kubernetes{
-		URL:         ts.URL,
-		labelFilter: labelFilter,
+		URL:            ts.URL,
+		labelFilter:    labelFilter,
+		NodeMetricName: "kubernetes_node",
 	}
 
 	var acc testutil.Accumulator

plugins/inputs/kubernetes/sample.conf

@@ -14,6 +14,12 @@
   ## OR
   # bearer_token_string = "abc_123"
 
+  ## Kubernetes Node Metric Name
+  ## The default Kubernetes node metric name (i.e. kubernetes_node) is the same
+  ## for the kubernetes and kube_inventory plugins. To avoid conflicts, set this
+  ## option to a different value.
+  # node_metric_name = "kubernetes_node"
+
   ## Pod labels to be added as tags.  An empty array for both include and
   ## exclude will include all labels.
   # label_include = []