feat(target-allocator): Add support for scrape-classes

.chloggen/allocator-scrapeclasses.yaml

@@ -0,0 +1,18 @@
+# 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. collector, target allocator, auto-instrumentation, opamp, github action)
+component: target allocator
+
+# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add support for prometheus scrape classes
+
+# One or more tracking issues related to the change
+issues: [3600]
+
+# (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:
+  Added support for configuring `scrapeClasses` when using the PrometheusCR-feature of the target allocator.
+  The format of the `scrapeClasses` array is exactly as same as `spec.scrapeClasses` of the `Prometheus` CRD.

README.md

@@ -708,6 +708,7 @@ spec:
       enabled: true
       serviceMonitorSelector: {}
       podMonitorSelector: {}
+      scrapeClasses: []
   config:
     receivers:
       prometheus:
@@ -724,6 +725,9 @@ spec:
 EOF
 ```
 
+The `scrapeClasses` attribute refers to the ScrapeClass feature of the Prometheus Operator.
+Refer to https://prometheus-operator.dev/docs/developer/scrapeclass/ to learn more about scrape classes.
+
 ## Configure resource attributes
 
 The OpenTelemetry Operator can automatically set resource attributes as defined in the 

apis/v1alpha1/convert.go

@@ -187,6 +187,7 @@ func tov1beta1TA(in OpenTelemetryTargetAllocator) v1beta1.TargetAllocatorEmbedde
 		PrometheusCR: v1beta1.TargetAllocatorPrometheusCR{
 			Enabled:        in.PrometheusCR.Enabled,
 			ScrapeInterval: in.PrometheusCR.ScrapeInterval,
+			ScrapeClasses:  in.PrometheusCR.ScrapeClasses,
 			// prometheus_cr.pod_monitor_selector shouldn't be nil when selector is empty
 			PodMonitorSelector: &metav1.LabelSelector{
 				MatchLabels: in.PrometheusCR.PodMonitorSelector,
@@ -458,6 +459,7 @@ func tov1alpha1TA(in v1beta1.TargetAllocatorEmbedded) OpenTelemetryTargetAllocat
 		PrometheusCR: OpenTelemetryTargetAllocatorPrometheusCR{
 			Enabled:                in.PrometheusCR.Enabled,
 			ScrapeInterval:         in.PrometheusCR.ScrapeInterval,
+			ScrapeClasses:          in.PrometheusCR.ScrapeClasses,
 			PodMonitorSelector:     podMonitorSelector,
 			ServiceMonitorSelector: serviceMonitorSelector,
 		},

apis/v1alpha1/opentelemetrycollector_types.go

@@ -10,6 +10,8 @@ import (
 	networkingv1 "k8s.io/api/networking/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/intstr"
+
+	"github.com/open-telemetry/opentelemetry-operator/apis/v1beta1"
 )
 
 // ManagementStateType defines the type for CR management states.
@@ -389,6 +391,12 @@ type OpenTelemetryTargetAllocatorPrometheusCR struct {
 	// +kubebuilder:default:="30s"
 	// +kubebuilder:validation:Format:=duration
 	ScrapeInterval *metav1.Duration `json:"scrapeInterval,omitempty"`
+	// ScrapeClasses to be referenced by PodMonitors and ServiceMonitors to include common configuration.
+	// If specified, expects an array of ScrapeClass objects as specified by https://prometheus-operator.dev/docs/api-reference/api/#monitoring.coreos.com/v1.ScrapeClass.
+	// +optional
+	// +listType=atomic
+	// +kubebuilder:pruning:PreserveUnknownFields
+	ScrapeClasses []v1beta1.AnyConfig `json:"scrapeClasses,omitempty"`
 	// PodMonitors to be selected for target discovery.
 	// This is a map of {key,value} pairs. Each {key,value} in the map is going to exactly match a label in a
 	// PodMonitor's meta labels. The requirements are ANDed.

apis/v1beta1/targetallocator_types.go

@@ -25,6 +25,12 @@ type TargetAllocatorPrometheusCR struct {
 	// +kubebuilder:default:="30s"
 	// +kubebuilder:validation:Format:=duration
 	ScrapeInterval *metav1.Duration `json:"scrapeInterval,omitempty"`
+	// ScrapeClasses to be referenced by PodMonitors and ServiceMonitors to include common configuration.
+	// If specified, expects an array of ScrapeClass objects as specified by https://prometheus-operator.dev/docs/api-reference/api/#monitoring.coreos.com/v1.ScrapeClass.
+	// +optional
+	// +listType=atomic
+	// +kubebuilder:pruning:PreserveUnknownFields
+	ScrapeClasses []AnyConfig `json:"scrapeClasses,omitempty"`
 	// PodMonitors to be selected for target discovery.
 	// A label selector is a label query over a set of resources. The result of matchLabels and
 	// matchExpressions are ANDed. An empty label selector matches all objects. A null

bundle/community/manifests/opentelemetry.io_opentelemetrycollectors.yaml

@@ -3237,6 +3237,12 @@ spec:
                         additionalProperties:
                           type: string
                         type: object
+                      scrapeClasses:
+                        items:
+                          type: object
+                        type: array
+                        x-kubernetes-list-type: atomic
+                        x-kubernetes-preserve-unknown-fields: true
                       scrapeInterval:
                         default: 30s
                         format: duration
@@ -8027,6 +8033,12 @@ spec:
                             type: object
                         type: object
                         x-kubernetes-map-type: atomic
+                      scrapeClasses:
+                        items:
+                          type: object
+                        type: array
+                        x-kubernetes-list-type: atomic
+                        x-kubernetes-preserve-unknown-fields: true
                       scrapeConfigSelector:
                         properties:
                           matchExpressions:

bundle/community/manifests/opentelemetry.io_targetallocators.yaml

@@ -2335,6 +2335,12 @@ spec:
                         type: object
                     type: object
                     x-kubernetes-map-type: atomic
+                  scrapeClasses:
+                    items:
+                      type: object
+                    type: array
+                    x-kubernetes-list-type: atomic
+                    x-kubernetes-preserve-unknown-fields: true
                   scrapeConfigSelector:
                     properties:
                       matchExpressions:

bundle/openshift/manifests/opentelemetry.io_opentelemetrycollectors.yaml

@@ -3236,6 +3236,12 @@ spec:
                         additionalProperties:
                           type: string
                         type: object
+                      scrapeClasses:
+                        items:
+                          type: object
+                        type: array
+                        x-kubernetes-list-type: atomic
+                        x-kubernetes-preserve-unknown-fields: true
                       scrapeInterval:
                         default: 30s
                         format: duration
@@ -8026,6 +8032,12 @@ spec:
                             type: object
                         type: object
                         x-kubernetes-map-type: atomic
+                      scrapeClasses:
+                        items:
+                          type: object
+                        type: array
+                        x-kubernetes-list-type: atomic
+                        x-kubernetes-preserve-unknown-fields: true
                       scrapeConfigSelector:
                         properties:
                           matchExpressions:

bundle/openshift/manifests/opentelemetry.io_targetallocators.yaml

@@ -2335,6 +2335,12 @@ spec:
                         type: object
                     type: object
                     x-kubernetes-map-type: atomic
+                  scrapeClasses:
+                    items:
+                      type: object
+                    type: array
+                    x-kubernetes-list-type: atomic
+                    x-kubernetes-preserve-unknown-fields: true
                   scrapeConfigSelector:
                     properties:
                       matchExpressions:

cmd/otel-allocator/internal/config/config.go

@@ -87,9 +87,10 @@ type PrometheusCRConfig struct {
 	ScrapeConfigNamespaceSelector   *metav1.LabelSelector         `yaml:"scrape_config_namespace_selector,omitempty"`
 	ProbeSelector                   *metav1.LabelSelector         `yaml:"probe_selector,omitempty"`
 	ProbeNamespaceSelector          *metav1.LabelSelector         `yaml:"probe_namespace_selector,omitempty"`
-	ScrapeProtocols                 []monitoringv1.ScrapeProtocol `yaml:"scrape_protocols,omitempty"`
 	ScrapeInterval                  model.Duration                `yaml:"scrape_interval,omitempty"`
 	EvaluationInterval              model.Duration                `yaml:"evaluation_interval,omitempty"`
+	ScrapeProtocols                 []monitoringv1.ScrapeProtocol `yaml:"scrape_protocols,omitempty"`
+	ScrapeClasses                   []monitoringv1.ScrapeClass    `yaml:"scrape_classes,omitempty"`
 }
 
 type HTTPSServerConfig struct {

cmd/otel-allocator/internal/watcher/promOperator.go

@@ -83,6 +83,7 @@ func NewPrometheusCRWatcher(
 				ProbeNamespaceSelector:          cfg.PrometheusCR.ProbeNamespaceSelector,
 				ServiceDiscoveryRole:            &serviceDiscoveryRole,
 				ScrapeProtocols:                 cfg.PrometheusCR.ScrapeProtocols,
+				ScrapeClasses:                   cfg.PrometheusCR.ScrapeClasses,
 			},
 			EvaluationInterval: monitoringv1.Duration(cfg.PrometheusCR.EvaluationInterval.String()),
 		},

cmd/otel-allocator/internal/watcher/promOperator_test.go

@@ -44,6 +44,7 @@ func TestLoadConfig(t *testing.T) {
 		name            string
 		serviceMonitors []*monitoringv1.ServiceMonitor
 		podMonitors     []*monitoringv1.PodMonitor
+		scrapeClasses   []*monitoringv1.ScrapeClass
 		scrapeConfigs   []*promv1alpha1.ScrapeConfig
 		probes          []*monitoringv1.Probe
 		want            *promconfig.Config
@@ -919,6 +920,68 @@ func TestLoadConfig(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "pod monitor with referenced scrape class",
+			podMonitors: []*monitoringv1.PodMonitor{
+				{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      "simple",
+						Namespace: namespace,
+					},
+					Spec: monitoringv1.PodMonitorSpec{
+						JobLabel:        "test",
+						ScrapeClassName: ptr.To("attach-node-metadata"),
+						PodMetricsEndpoints: []monitoringv1.PodMetricsEndpoint{
+							{
+								Port: &portName,
+							},
+						},
+					},
+				},
+			},
+			cfg: allocatorconfig.Config{
+				PrometheusCR: allocatorconfig.PrometheusCRConfig{
+					PodMonitorSelector: &metav1.LabelSelector{},
+					ScrapeClasses: []monitoringv1.ScrapeClass{
+						{
+							Name: "attach-node-metadata",
+							AttachMetadata: &monitoringv1.AttachMetadata{
+								Node: ptr.To(true),
+							},
+						},
+					},
+				},
+			},
+			want: &promconfig.Config{
+				ScrapeConfigs: []*promconfig.ScrapeConfig{
+					{
+						JobName:         "podMonitor/test/simple/0",
+						ScrapeInterval:  model.Duration(60 * time.Second),
+						ScrapeProtocols: promconfig.DefaultScrapeProtocols,
+						ScrapeTimeout:   model.Duration(10 * time.Second),
+						HonorTimestamps: true,
+						HonorLabels:     false,
+						Scheme:          "http",
+						MetricsPath:     "/metrics",
+						ServiceDiscoveryConfigs: []discovery.Config{
+							&kubeDiscovery.SDConfig{
+								Role: "pod",
+								NamespaceDiscovery: kubeDiscovery.NamespaceDiscovery{
+									Names:               []string{namespace},
+									IncludeOwnNamespace: false,
+								},
+								HTTPClientConfig: config.DefaultHTTPClientConfig,
+								AttachMetadata: kubeDiscovery.AttachMetadataConfig{
+									Node: true, // Added by scrape-class!
+								},
+							},
+						},
+						HTTPClientConfig:  config.DefaultHTTPClientConfig,
+						EnableCompression: true,
+					},
+				},
+			},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -1346,6 +1409,7 @@ func getTestPrometheusCRWatcher(
 				ProbeNamespaceSelector:          cfg.PrometheusCR.ProbeNamespaceSelector,
 				ScrapeConfigSelector:            cfg.PrometheusCR.ScrapeConfigSelector,
 				ScrapeConfigNamespaceSelector:   cfg.PrometheusCR.ScrapeConfigNamespaceSelector,
+				ScrapeClasses:                   cfg.PrometheusCR.ScrapeClasses,
 				ServiceDiscoveryRole:            &serviceDiscoveryRole,
 			},
 			EvaluationInterval: monitoringv1.Duration(cfg.PrometheusCR.EvaluationInterval.String()),

config/crd/bases/opentelemetry.io_opentelemetrycollectors.yaml

@@ -3223,6 +3223,12 @@ spec:
                         additionalProperties:
                           type: string
                         type: object
+                      scrapeClasses:
+                        items:
+                          type: object
+                        type: array
+                        x-kubernetes-list-type: atomic
+                        x-kubernetes-preserve-unknown-fields: true
                       scrapeInterval:
                         default: 30s
                         format: duration
@@ -8013,6 +8019,12 @@ spec:
                             type: object
                         type: object
                         x-kubernetes-map-type: atomic
+                      scrapeClasses:
+                        items:
+                          type: object
+                        type: array
+                        x-kubernetes-list-type: atomic
+                        x-kubernetes-preserve-unknown-fields: true
                       scrapeConfigSelector:
                         properties:
                           matchExpressions:

config/crd/bases/opentelemetry.io_targetallocators.yaml

@@ -2333,6 +2333,12 @@ spec:
                         type: object
                     type: object
                     x-kubernetes-map-type: atomic
+                  scrapeClasses:
+                    items:
+                      type: object
+                    type: array
+                    x-kubernetes-list-type: atomic
+                    x-kubernetes-preserve-unknown-fields: true
                   scrapeConfigSelector:
                     properties:
                       matchExpressions:

docs/api/opentelemetrycollectors.md

@@ -13477,6 +13477,14 @@ PodMonitor's meta labels. The requirements are ANDed.
 Empty or nil map matches all pod monitors.<br/>
         </td>
         <td>false</td>
+      </tr><tr>
+        <td><b>scrapeClasses</b></td>
+        <td>[]object</td>
+        <td>
+          ScrapeClasses to be referenced by PodMonitors and ServiceMonitors to include common configuration.
+If specified, expects an array of ScrapeClass objects as specified by https://prometheus-operator.dev/docs/api-reference/api/#monitoring.coreos.com/v1.ScrapeClass.<br/>
+        </td>
+        <td>false</td>
       </tr><tr>
         <td><b>scrapeInterval</b></td>
         <td>string</td>
@@ -33557,6 +33565,14 @@ matchExpressions are ANDed. An empty label selector matches all objects. A null
 label selector matches no objects.<br/>
         </td>
         <td>false</td>
+      </tr><tr>
+        <td><b>scrapeClasses</b></td>
+        <td>[]object</td>
+        <td>
+          ScrapeClasses to be referenced by PodMonitors and ServiceMonitors to include common configuration.
+If specified, expects an array of ScrapeClass objects as specified by https://prometheus-operator.dev/docs/api-reference/api/#monitoring.coreos.com/v1.ScrapeClass.<br/>
+        </td>
+        <td>false</td>
       </tr><tr>
         <td><b><a href="#opentelemetrycollectorspectargetallocatorprometheuscrscrapeconfigselector">scrapeConfigSelector</a></b></td>
         <td>object</td>

docs/api/targetallocators.md

@@ -9591,6 +9591,14 @@ matchExpressions are ANDed. An empty label selector matches all objects. A null
 label selector matches no objects.<br/>
         </td>
         <td>false</td>
+      </tr><tr>
+        <td><b>scrapeClasses</b></td>
+        <td>[]object</td>
+        <td>
+          ScrapeClasses to be referenced by PodMonitors and ServiceMonitors to include common configuration.
+If specified, expects an array of ScrapeClass objects as specified by https://prometheus-operator.dev/docs/api-reference/api/#monitoring.coreos.com/v1.ScrapeClass.<br/>
+        </td>
+        <td>false</td>
       </tr><tr>
         <td><b><a href="#targetallocatorspecprometheuscrscrapeconfigselector">scrapeConfigSelector</a></b></td>
         <td>object</td>

internal/manifests/targetallocator/configmap.go

@@ -94,6 +94,10 @@ func ConfigMap(params Params) (*corev1.ConfigMap, error) {
 			prometheusCRConfig["scrape_interval"] = taSpec.PrometheusCR.ScrapeInterval.Duration
 		}
 
+		if taSpec.PrometheusCR.ScrapeClasses != nil {
+			prometheusCRConfig["scrape_classes"] = taSpec.PrometheusCR.ScrapeClasses
+		}
+
 		if taSpec.PrometheusCR.AllowNamespaces != nil {
 			prometheusCRConfig["allow_namespaces"] = taSpec.PrometheusCR.AllowNamespaces
 		}