Add validation for pod/service monitors for TargetAllocator and skip invalid ones

.chloggen/target-allocator-use-recommended-prometheus-operator-interfaces.yaml

@@ -0,0 +1,16 @@
+# 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. operator, target allocator, 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: Use recommended interfaces(resource selector) by the prometheus-operator for watching CRs.
+
+# One or more tracking issues related to the change
+issues: [2309]
+
+# (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:

cmd/otel-allocator/README.md

@@ -124,7 +124,7 @@ to collector instance pods by default.
 
 
 ### RBAC
-The ServiceAccount that the TargetAllocator runs as, has to have access to the CRs. A role like this will provide that
+The ServiceAccount that the TargetAllocator runs as, has to have access to the CRs and the namespaces to watch for the pod and service monitors. A role like this will provide that
 access.
 ```yaml
 apiVersion: rbac.authorization.k8s.io/v1
@@ -139,6 +139,10 @@ rules:
   - podmonitors
   verbs:
   - '*'
+- apiGroups: [""]
+  resources:
+  - namespaces
+  verbs: ["list", "watch"]
 ```
 In addition, the TargetAllocator needs the same permissions as a Prometheus instance would to find the matching targets
 from the CR instances.

cmd/otel-allocator/config/config.go

@@ -39,18 +39,20 @@ const DefaultConfigFilePath string = "/conf/targetallocator.yaml"
 const DefaultCRScrapeInterval model.Duration = model.Duration(time.Second * 30)
 
 type Config struct {
-	ListenAddr             string             `yaml:"listen_addr,omitempty"`
-	KubeConfigFilePath     string             `yaml:"kube_config_file_path,omitempty"`
-	ClusterConfig          *rest.Config       `yaml:"-"`
-	RootLogger             logr.Logger        `yaml:"-"`
-	ReloadConfig           bool               `yaml:"-"`
-	LabelSelector          map[string]string  `yaml:"label_selector,omitempty"`
-	PromConfig             *promconfig.Config `yaml:"config"`
-	AllocationStrategy     *string            `yaml:"allocation_strategy,omitempty"`
-	FilterStrategy         *string            `yaml:"filter_strategy,omitempty"`
-	PrometheusCR           PrometheusCRConfig `yaml:"prometheus_cr,omitempty"`
-	PodMonitorSelector     map[string]string  `yaml:"pod_monitor_selector,omitempty"`
-	ServiceMonitorSelector map[string]string  `yaml:"service_monitor_selector,omitempty"`
+	ListenAddr                      string             `yaml:"listen_addr,omitempty"`
+	KubeConfigFilePath              string             `yaml:"kube_config_file_path,omitempty"`
+	ClusterConfig                   *rest.Config       `yaml:"-"`
+	RootLogger                      logr.Logger        `yaml:"-"`
+	ReloadConfig                    bool               `yaml:"-"`
+	LabelSelector                   map[string]string  `yaml:"label_selector,omitempty"`
+	PromConfig                      *promconfig.Config `yaml:"config"`
+	AllocationStrategy              *string            `yaml:"allocation_strategy,omitempty"`
+	FilterStrategy                  *string            `yaml:"filter_strategy,omitempty"`
+	PrometheusCR                    PrometheusCRConfig `yaml:"prometheus_cr,omitempty"`
+	PodMonitorSelector              map[string]string  `yaml:"pod_monitor_selector,omitempty"`
+	ServiceMonitorSelector          map[string]string  `yaml:"service_monitor_selector,omitempty"`
+	ServiceMonitorNamespaceSelector map[string]string  `yaml:"service_monitor_namespace_selector,omitempty"`
+	PodMonitorNamespaceSelector     map[string]string  `yaml:"pod_monitor_namespace_selector,omitempty"`
 }
 
 type PrometheusCRConfig struct {

cmd/otel-allocator/main.go

@@ -110,7 +110,7 @@ func main() {
 	defer close(interrupts)
 
 	if cfg.PrometheusCR.Enabled {
-		promWatcher, err = allocatorWatcher.NewPrometheusCRWatcher(setupLog.WithName("prometheus-cr-watcher"), *cfg)
+		promWatcher, err = allocatorWatcher.NewPrometheusCRWatcher(ctx, setupLog.WithName("prometheus-cr-watcher"), *cfg)
 		if err != nil {
 			setupLog.Error(err, "Can't start the prometheus watcher")
 			os.Exit(1)