Add metric metadata syncer to SignalFx exporter

exporter/signalfxexporter/README.md

@@ -1,6 +1,10 @@
 # SignalFx Metrics Exporter
 
-How to send metrics to SignalFx.
+This exporter can be used to send metrics to SignalFx.
+
+Apart from metrics, the exporter is also capable of sending metric metadata (properties and tags)
+to SignalFx. Currently, only metric metadata updates from the [k8s_cluster receiver](../../receiver/k8sclusterreceiver/README.md)
+are supported.
 
 The following configuration options are required:
 
@@ -15,6 +19,9 @@ The following configuration options can also be configured:
 - `ingest_url` (default = https://ingest.`realm`.signalfx.com/v2/datapoint): Destination
 where SignalFx metrics are sent. If this option is specified, `realm` is ignored.
 If path is not specified, `/v2/datapoint` is used.
+- `api_url` (default = https://api.`realm`.signalfx.com/): Destination to which SignalFx
+[properties and tags](https://docs.signalfx.com/en/latest/metrics-metadata/metrics-metadata.html#metrics-metadata) are sent.
+- `log_dimension_updates` (default = `false`): Whether or not to log dimension updates.
 
 Example:
 

exporter/signalfxexporter/config.go

@@ -42,6 +42,10 @@ type Config struct {
 	// If a path is specified it will use the one set by the config.
 	IngestURL string `mapstructure:"ingest_url"`
 
+	// APIURL is the destination to where SignalFx metadata will be sent. This
+	// value takes precedence over the value of Realm
+	APIURL string `mapstructure:"api_url"`
+
 	// Timeout is the maximum timeout for HTTP request sending trace data. The
 	// default value is 5 seconds.
 	Timeout time.Duration `mapstructure:"timeout"`
@@ -51,6 +55,9 @@ type Config struct {
 	// exporter, eg: "User-Agent" can be set to a custom value if specified
 	// here.
 	Headers map[string]string `mapstructure:"headers"`
+
+	// Whether to log dimension updates being sent to SignalFx.
+	LogDimensionUpdates bool `mapstructure:"log_dimension_updates"`
 }
 
 func (cfg *Config) getOptionsFromConfig() (*exporterOptions, error) {
@@ -63,19 +70,32 @@ func (cfg *Config) getOptionsFromConfig() (*exporterOptions, error) {
 		return nil, fmt.Errorf("invalid \"ingest_url\": %v", err)
 	}
 
+	apiURL, err := cfg.getAPIURL()
+	if err != nil {
+		return nil, fmt.Errorf("invalid \"api_url\": %v", err)
+	}
+
 	if cfg.Timeout == 0 {
 		cfg.Timeout = 5 * time.Second
 	}
 
 	return &exporterOptions{
-		ingestURL:   ingestURL,
-		httpTimeout: cfg.Timeout,
+		ingestURL:    ingestURL,
+		apiURL:       apiURL,
+		httpTimeout:  cfg.Timeout,
+		token:        cfg.AccessToken,
+		logDimUpdate: cfg.LogDimensionUpdates,
 	}, nil
 }
 
 func (cfg *Config) validateConfig() error {
-	if cfg.Realm == "" && cfg.IngestURL == "" {
-		return errors.New("requires a non-empty \"realm\" or \"ingest_url\"")
+	if cfg.AccessToken == "" {
+		return errors.New("requires a non-empty \"access_token\"")
+	}
+
+	if cfg.Realm == "" && (cfg.IngestURL == "" || cfg.APIURL == "") {
+		return errors.New("requires a non-empty \"realm\", or" +
+			" \"ingest_url\" and \"api_url\" should be explicitly set")
 	}
 
 	if cfg.Timeout < 0 {
@@ -104,3 +124,10 @@ func (cfg *Config) getIngestURL() (out *url.URL, err error) {
 
 	return out, err
 }
+
+func (cfg *Config) getAPIURL() (*url.URL, error) {
+	if cfg.APIURL == "" {
+		return url.Parse(fmt.Sprintf("https://api.%s.signalfx.com", cfg.Realm))
+	}
+	return url.Parse(cfg.APIURL)
+}

exporter/signalfxexporter/config_test.go

@@ -74,6 +74,7 @@ func TestConfig_getOptionsFromConfig(t *testing.T) {
 		AccessToken      string
 		Realm            string
 		IngestURL        string
+		APIURL           string
 		Timeout          time.Duration
 		Headers          map[string]string
 	}
@@ -86,32 +87,46 @@ func TestConfig_getOptionsFromConfig(t *testing.T) {
 		{
 			name: "Test URL overrides",
 			fields: fields{
-				Realm:     "us0",
-				IngestURL: "https://ingest.us1.signalfx.com/",
+				Realm:       "us0",
+				AccessToken: "access_token",
+				IngestURL:   "https://ingest.us1.signalfx.com/",
+				APIURL:      "https://api.us1.signalfx.com/",
 			},
 			want: &exporterOptions{
 				ingestURL: &url.URL{
 					Scheme: "https",
 					Host:   "ingest.us1.signalfx.com",
 					Path:   "/v2/datapoint",
 				},
+				apiURL: &url.URL{
+					Scheme: "https",
+					Host:   "api.us1.signalfx.com",
+					Path:   "/",
+				},
 				httpTimeout: 5 * time.Second,
+				token:       "access_token",
 			},
 			wantErr: false,
 		},
 		{
 			name: "Test URL from Realm",
 			fields: fields{
-				Realm:   "us0",
-				Timeout: 10 * time.Second,
+				Realm:       "us0",
+				AccessToken: "access_token",
+				Timeout:     10 * time.Second,
 			},
 			want: &exporterOptions{
 				ingestURL: &url.URL{
 					Scheme: "https",
 					Host:   "ingest.us0.signalfx.com",
 					Path:   "/v2/datapoint",
 				},
+				apiURL: &url.URL{
+					Scheme: "https",
+					Host:   "api.us0.signalfx.com",
+				},
 				httpTimeout: 10 * time.Second,
+				token:       "access_token",
 			},
 			wantErr: false,
 		},
@@ -128,6 +143,7 @@ func TestConfig_getOptionsFromConfig(t *testing.T) {
 				AccessToken:      tt.fields.AccessToken,
 				Realm:            tt.fields.Realm,
 				IngestURL:        tt.fields.IngestURL,
+				APIURL:           tt.fields.APIURL,
 				Timeout:          tt.fields.Timeout,
 				Headers:          tt.fields.Headers,
 			}