lib/promscrape/discovery/kubernetes: return back support role: endpointslices, since it is used by VictoriaMetrics operator

This is a follow up commit after 31b42b30b6

docs/CHANGELOG.md

@@ -17,7 +17,7 @@ sort: 15
 * FEATURE: add `quantiles("quantileLabel", phi1, ..., phiN, q)` aggregate function to [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html), which calculates the given `phi*` quantiles over time series returned by `q`. See [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1573).
 
 * BUGFIX: rename `sign` function to `sgn` in order to be consistent with PromQL. See [this pull request from Prometheus](https://github.com/prometheus/prometheus/pull/8457).
-* BUGFIX: vmagent: rename `role: endpointslices` to `role: endpointslice` in [kubernetes_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#kubernetes_sd_config) in order to be consistent with Prometheus. See [the corresponding code in Prometheus](https://github.com/prometheus/prometheus/blob/2ec6c7dbb82b72834021e01f1773eb90a67a371f/discovery/kubernetes/kubernetes.go#L99).
+* BUGFIX: vmagent: add `role: endpointslice` in [kubernetes_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#kubernetes_sd_config) in order to be consistent with Prometheus. Previously this role was supported with incorrect name: `role: endpointslices`. Now both `endpointslice` and `endpointslices` are supported. See [the corresponding code in Prometheus](https://github.com/prometheus/prometheus/blob/2ec6c7dbb82b72834021e01f1773eb90a67a371f/discovery/kubernetes/kubernetes.go#L99).
 * BUGFIX: improve the detection of the needed free space for background merge operation. This should prevent from possible out of disk space crashes during big merges. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1560).
 * BUGFIX: vmauth: remove trailing slash from the full url before requesting it from the backend. See [this pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/1554).
 * BUGFIX: [vmbackupmanager](https://docs.victoriametrics.com/vmbackupmanager.html): fix timeout error when snapshot takes longer than 10 seconds. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1571).

lib/promscrape/discovery/kubernetes/api.go

@@ -15,10 +15,11 @@ type apiConfig struct {
 }
 
 func newAPIConfig(sdc *SDConfig, baseDir string, swcFunc ScrapeWorkConstructorFunc) (*apiConfig, error) {
-	switch sdc.Role {
+	role := sdc.role()
+	switch role {
 	case "node", "pod", "service", "endpoints", "endpointslice", "ingress":
 	default:
-		return nil, fmt.Errorf("unexpected `role`: %q; must be one of `node`, `pod`, `service`, `endpoints`, `endpointslice` or `ingress`", sdc.Role)
+		return nil, fmt.Errorf("unexpected `role`: %q; must be one of `node`, `pod`, `service`, `endpoints`, `endpointslice` or `ingress`", role)
 	}
 	ac, err := sdc.HTTPClientConfig.NewConfig(baseDir)
 	if err != nil {

lib/promscrape/discovery/kubernetes/api_watcher.go

@@ -66,12 +66,13 @@ func newAPIWatcher(apiServer string, ac *promauth.Config, sdc *SDConfig, swcFunc
 	selectors := sdc.Selectors
 	proxyURL := sdc.ProxyURL.URL()
 	gw := getGroupWatcher(apiServer, ac, namespaces, selectors, proxyURL)
+	role := sdc.role()
 	return &apiWatcher{
-		role:             sdc.Role,
+		role:             role,
 		swcFunc:          swcFunc,
 		gw:               gw,
 		swosByURLWatcher: make(map[*urlWatcher]map[string][]interface{}),
-		swosCount:        metrics.GetOrCreateCounter(fmt.Sprintf(`vm_promscrape_discovery_kubernetes_scrape_works{role=%q}`, sdc.Role)),
+		swosCount:        metrics.GetOrCreateCounter(fmt.Sprintf(`vm_promscrape_discovery_kubernetes_scrape_works{role=%q}`, role)),
 	}
 }
 

lib/promscrape/discovery/kubernetes/kubernetes.go

@@ -18,8 +18,11 @@ var SDCheckInterval = flag.Duration("promscrape.kubernetesSDCheckInterval", 30*t
 //
 // See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#kubernetes_sd_config
 type SDConfig struct {
-	APIServer        string                    `yaml:"api_server,omitempty"`
+	APIServer string `yaml:"api_server,omitempty"`
-	Role             string                    `yaml:"role"`
+
+	// Use role() function for accessing the Role field
+	Role string `yaml:"role"`
+
 	HTTPClientConfig promauth.HTTPClientConfig `yaml:",inline"`
 	ProxyURL         proxy.URL                 `yaml:"proxy_url,omitempty"`
 	Namespaces       Namespaces                `yaml:"namespaces,omitempty"`
@@ -29,6 +32,15 @@ type SDConfig struct {
 	startErr error
 }
 
+func (sdc *SDConfig) role() string {
+	if sdc.Role == "endpointslices" {
+		// The endpointslices role isn't supported by Prometheus, but it is used by VictoriaMetrics operator.
+		// Support it for backwards compatibility.
+		return "endpointslice"
+	}
+	return sdc.Role
+}
+
 // Namespaces represents namespaces for SDConfig
 type Namespaces struct {
 	Names []string `yaml:"names"`