[exporter/signalfxexporter] Make sending tags from the SignalFx Exporter configurable (#43799)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description

New optional configuration flag `drop_tags` has been added to SignalFx
Exporter to allow users to disable tags metadata sending.

This feature has been introduced due to a common issue among Splunk
Observability customers when they're receiving more tags than allowed
limit.

<!--Describe what testing was performed and which tests were added.-->
#### Testing

- added unit test to check if `drop_tags` flag is working

<!--Describe the documentation added.-->
#### Documentation

- added new config option description in README file

<!--Please delete paragraphs that you did not use before submitting.-->

Author: jkoronaAtCisco

.chloggen/signalfxexporter-drop-tags.yaml

@@ -0,0 +1,32 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. receiver/filelog)
+component: exporter/signalfx
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Makes sending tags from SignalFx Exporter configurable"
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [43799]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: |
+  New optional configuration flag `drop_tags` has been added to SignalFx Exporter to allow users to disable tag metadata sending.
+  This feature has been introduced due to a common issue among Splunk Observability customers when they're receiving more tags 
+  than allowed limit. 
+  
+  
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

exporter/signalfxexporter/README.md

@@ -26,13 +26,13 @@ The following configuration options are required:
 
 - `access_token` (no default): The access token is the [authentication token
   provided by Splunk Observability
-  Cloud](https://docs.splunk.com/observability/en/admin/authentication/authentication-tokens/manage-usage.html).
+  Cloud](https://help.splunk.com/en/splunk-observability-cloud/administer/authentication-and-security/authentication-tokens/manage-usage-with-access-tokens).
   The access token can be obtained from the web app.
 - Either `realm` or both `api_url` and `ingest_url`. Both `api_url` and
   `ingest_url` take precedence over `realm`.
   - `realm` (no default): SignalFx realm where the data will be received.
   - `api_url` (no default): Destination to which [properties and
-    tags](https://docs.splunk.com/observability/en/metrics-and-metadata/metrics-finder-metadata-catalog.html)
+    tags](https://help.splunk.com/en/splunk-observability-cloud/data-tools/metric-finder-and-metadata-catalogue)
     are sent. If `realm` is set, this option is derived and will be
     `https://api.{realm}.signalfx.com`. If a value is explicitly set, the
     value of `realm` will not be used in determining `api_url`. The explicit
@@ -128,6 +128,7 @@ The following configuration options can also be configured:
   - `max_conns_per_host` (default = 20): The maximum total number of connections the client can keep open per host.
   - `idle_conn_timeout` (default = 30s): The maximum amount of time an idle connection will remain open before closing itself.
   - `timeout` (default = 10s): Amount of time to wait for the dimension HTTP request to complete.
+  - `drop_tags` (default = false): Flag that indicates whether to drop the tags from the metadata sent to Splunk Observability Cloud by the exporter.
 - `nonalphanumeric_dimension_chars`: (default = `"_-."`) A string of characters 
 that are allowed to be used as a dimension key in addition to alphanumeric 
 characters. Each nonalphanumeric dimension key character that isn't in this string 

exporter/signalfxexporter/config.go

@@ -156,6 +156,7 @@ type DimensionClientConfig struct {
 	MaxConnsPerHost     int           `mapstructure:"max_conns_per_host"`
 	IdleConnTimeout     time.Duration `mapstructure:"idle_conn_timeout"`
 	Timeout             time.Duration `mapstructure:"timeout"`
+	DropTags            bool          `mapstructure:"drop_tags"`
 }
 
 func (cfg *Config) getMetricTranslator(done chan struct{}) (*translation.MetricTranslator, error) {

exporter/signalfxexporter/config_test.go

@@ -84,6 +84,7 @@ func TestLoadConfig(t *testing.T) {
 					MaxConnsPerHost:     20,
 					IdleConnTimeout:     30 * time.Second,
 					Timeout:             10 * time.Second,
+					DropTags:            false,
 				},
 				ExcludeMetrics:      nil,
 				IncludeMetrics:      nil,
@@ -163,6 +164,7 @@ func TestLoadConfig(t *testing.T) {
 					MaxConnsPerHost:     10000,
 					IdleConnTimeout:     2 * time.Hour,
 					Timeout:             20 * time.Second,
+					DropTags:            false,
 				},
 				ExcludeMetrics: []dpfilters.MetricFilter{
 					{

exporter/signalfxexporter/exporter.go

@@ -153,6 +153,7 @@ func (se *signalfxExporter) start(ctx context.Context, host component.Host) (err
 			MaxIdleConnsPerHost: se.config.DimensionClient.MaxIdleConnsPerHost,
 			IdleConnTimeout:     se.config.DimensionClient.IdleConnTimeout,
 			Timeout:             se.config.DimensionClient.Timeout,
+			DropTags:            se.config.DimensionClient.DropTags,
 		})
 	dimClient.Start()
 

exporter/signalfxexporter/internal/dimensions/dimclient.go

@@ -58,6 +58,8 @@ type DimensionClient struct {
 	metricsConverter translation.MetricsConverter
 	// ExcludeProperties will filter DimensionUpdate content to not submit undesired metadata.
 	ExcludeProperties []dpfilters.PropertyFilter
+	// dropTags specifies whether tags should be omitted or not. Default value is false.
+	dropTags bool
 }
 
 type queuedDimension struct {
@@ -82,6 +84,7 @@ type DimensionClientOptions struct {
 	MaxIdleConnsPerHost int
 	IdleConnTimeout     time.Duration
 	Timeout             time.Duration
+	DropTags            bool
 }
 
 // NewDimensionClient returns a new client
@@ -118,6 +121,7 @@ func NewDimensionClient(options DimensionClientOptions) *DimensionClient {
 		logUpdates:        options.LogUpdates,
 		metricsConverter:  options.MetricsConverter,
 		ExcludeProperties: options.ExcludeProperties,
+		dropTags:          options.DropTags,
 	}
 }
 
@@ -342,6 +346,11 @@ func (dc *DimensionClient) makePatchRequest(ctx context.Context, dim *DimensionU
 }
 
 func (dc *DimensionClient) filterDimensionUpdate(update *DimensionUpdate) *DimensionUpdate {
+	// clear tags list if dropTags option is set
+	if dc.dropTags {
+		update.Tags = nil
+	}
+
 	for _, excludeRule := range dc.ExcludeProperties {
 		if excludeRule.DimensionName.Matches(update.Name) && excludeRule.DimensionValue.Matches(update.Value) {
 			for k, v := range update.Properties {

exporter/signalfxexporter/internal/dimensions/dimclient_test.go

@@ -186,6 +186,41 @@ func TestDimensionClient(t *testing.T) {
 		require.EqualValues(t, 1, server.requestCount.Load())
 	})
 
+	t.Run("send dimension without tags if dropTags option is set", func(t *testing.T) {
+		server.reset()
+		// set dropTags option
+		client.dropTags = true
+		defer func() { client.dropTags = false }()
+
+		require.NoError(t, client.acceptDimension(&DimensionUpdate{
+			Name:  "host",
+			Value: "test-box",
+			Properties: map[string]*string{
+				"a": newString("b"),
+				"c": newString("d"),
+				"e": nil,
+			},
+			Tags: map[string]bool{
+				"active":     true,
+				"terminated": false,
+			},
+		}))
+
+		server.handleRequest()
+		require.Equal(t, []dim{
+			{
+				Key:   "host",
+				Value: "test-box",
+				Properties: map[string]*string{
+					"a": newString("b"),
+					"c": newString("d"),
+					"e": nil,
+				},
+			},
+		}, server.acceptedDims)
+		require.EqualValues(t, 1, server.requestCount.Load())
+	})
+
 	t.Run("send a distinct prop/tag set for existing dim with server error", func(t *testing.T) {
 		server.reset()
 		server.respCode = http.StatusInternalServerError