Add v1alpha2 embedded Target Allocator struct (#2623)

Add and use the embedded Target Allocator struct for v1alpha2. The
changes mostly involve label selectors for Prometheus CR.

Worth noting that this involves a change in semantics for said
selectors, as an empty selector now selects nothing, which is in line
with the standard, but different from v1alpha1.

apis/v1alpha2/allocation_strategy.go

@@ -31,5 +31,5 @@ const (
 	TargetAllocatorAllocationStrategyConsistentHashing TargetAllocatorAllocationStrategy = "consistent-hashing"
 
 	// TargetAllocatorFilterStrategyRelabelConfig targets will be consistently drops targets based on the relabel_config.
-	TargetAllocatorFilterStrategyRelabelConfig TargetAllocatorFilterStrategy = "consistent-hashing"
+	TargetAllocatorFilterStrategyRelabelConfig TargetAllocatorFilterStrategy = "relabel-config"
 )

apis/v1alpha2/opentelemetrycollector_types.go

@@ -18,6 +18,7 @@ package v1alpha2
 
 import (
 	appsv1 "k8s.io/api/apps/v1"
+	v1 "k8s.io/api/core/v1"
 	networkingv1 "k8s.io/api/networking/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
@@ -120,7 +121,7 @@ type OpenTelemetryCollectorSpec struct {
 	OpenTelemetryCommonFields `json:",inline"`
 	// TargetAllocator indicates a value which determines whether to spawn a target allocation resource or not.
 	// +optional
-	TargetAllocator v1alpha1.OpenTelemetryTargetAllocator `json:"targetAllocator,omitempty"`
+	TargetAllocator TargetAllocatorEmbedded `json:"targetAllocator,omitempty"`
 	// Mode represents how the collector should be deployed (deployment, daemonset, statefulset or sidecar)
 	// +optional
 	Mode Mode `json:"mode,omitempty"`
@@ -165,6 +166,84 @@ type OpenTelemetryCollectorSpec struct {
 	DeploymentUpdateStrategy appsv1.DeploymentStrategy `json:"deploymentUpdateStrategy,omitempty"`
 }
 
+// TargetAllocatorEmbedded defines the configuration for the Prometheus target allocator, embedded in the
+// OpenTelemetryCollector spec.
+type TargetAllocatorEmbedded struct {
+	// Replicas is the number of pod instances for the underlying TargetAllocator. This should only be set to a value
+	// other than 1 if a strategy that allows for high availability is chosen. Currently, the only allocation strategy
+	// that can be run in a high availability mode is consistent-hashing.
+	// +optional
+	Replicas *int32 `json:"replicas,omitempty"`
+	// NodeSelector to schedule OpenTelemetry TargetAllocator pods.
+	// +optional
+	NodeSelector map[string]string `json:"nodeSelector,omitempty"`
+	// Resources to set on the OpenTelemetryTargetAllocator containers.
+	// +optional
+	Resources v1.ResourceRequirements `json:"resources,omitempty"`
+	// AllocationStrategy determines which strategy the target allocator should use for allocation.
+	// The current options are least-weighted, consistent-hashing and per-node. The default is
+	// consistent-hashing.
+	// +optional
+	// +kubebuilder:default:=consistent-hashing
+	AllocationStrategy TargetAllocatorAllocationStrategy `json:"allocationStrategy,omitempty"`
+	// FilterStrategy determines how to filter targets before allocating them among the collectors.
+	// The only current option is relabel-config (drops targets based on prom relabel_config).
+	// The default is relabel-config.
+	// +optional
+	// +kubebuilder:default:=relabel-config
+	FilterStrategy TargetAllocatorFilterStrategy `json:"filterStrategy,omitempty"`
+	// ServiceAccount indicates the name of an existing service account to use with this instance. When set,
+	// the operator will not automatically create a ServiceAccount for the TargetAllocator.
+	// +optional
+	ServiceAccount string `json:"serviceAccount,omitempty"`
+	// Image indicates the container image to use for the OpenTelemetry TargetAllocator.
+	// +optional
+	Image string `json:"image,omitempty"`
+	// Enabled indicates whether to use a target allocation mechanism for Prometheus targets or not.
+	// +optional
+	Enabled bool `json:"enabled,omitempty"`
+	// If specified, indicates the pod's scheduling constraints
+	// +optional
+	Affinity *v1.Affinity `json:"affinity,omitempty"`
+	// PrometheusCR defines the configuration for the retrieval of PrometheusOperator CRDs ( servicemonitor.monitoring.coreos.com/v1 and podmonitor.monitoring.coreos.com/v1 )  retrieval.
+	// All CR instances which the ServiceAccount has access to will be retrieved. This includes other namespaces.
+	// +optional
+	PrometheusCR TargetAllocatorPrometheusCR `json:"prometheusCR,omitempty"`
+	// SecurityContext configures the container security context for
+	// the targetallocator.
+	// +optional
+	SecurityContext *v1.SecurityContext `json:"securityContext,omitempty"`
+	// PodSecurityContext configures the pod security context for the
+	// targetallocator.
+	// +optional
+	PodSecurityContext *v1.PodSecurityContext `json:"podSecurityContext,omitempty"`
+	// TopologySpreadConstraints embedded kubernetes pod configuration option,
+	// controls how pods are spread across your cluster among failure-domains
+	// such as regions, zones, nodes, and other user-defined topology domains
+	// https://kubernetes.io/docs/concepts/workloads/pods/pod-topology-spread-constraints/
+	// +optional
+	TopologySpreadConstraints []v1.TopologySpreadConstraint `json:"topologySpreadConstraints,omitempty"`
+	// Toleration embedded kubernetes pod configuration option,
+	// controls how pods can be scheduled with matching taints
+	// +optional
+	Tolerations []v1.Toleration `json:"tolerations,omitempty"`
+	// ENV vars to set on the OpenTelemetry TargetAllocator's Pods. These can then in certain cases be
+	// consumed in the config file for the TargetAllocator.
+	// +optional
+	Env []v1.EnvVar `json:"env,omitempty"`
+	// ObservabilitySpec defines how telemetry data gets handled.
+	//
+	// +optional
+	// +kubebuilder:validation:Optional
+	// +operator-sdk:csv:customresourcedefinitions:type=spec,displayName="Observability"
+	Observability v1alpha1.ObservabilitySpec `json:"observability,omitempty"`
+	// PodDisruptionBudget specifies the pod disruption budget configuration to use
+	// for the target allocator workload.
+	//
+	// +optional
+	PodDisruptionBudget *PodDisruptionBudgetSpec `json:"podDisruptionBudget,omitempty"`
+}
+
 // OpenTelemetryCollectorStatus defines the observed state of OpenTelemetryCollector.
 type OpenTelemetryCollectorStatus struct {
 	// Scale is the OpenTelemetryCollector's scale subresource status.

controllers/builder_test.go

@@ -1150,10 +1150,10 @@ service:
 						},
 						Mode:   "statefulset",
 						Config: goodConfig,
-						TargetAllocator: v1alpha1.OpenTelemetryTargetAllocator{
+						TargetAllocator: v1alpha2.TargetAllocatorEmbedded{
 							Enabled:        true,
 							FilterStrategy: "relabel-config",
-							PrometheusCR: v1alpha1.OpenTelemetryTargetAllocatorPrometheusCR{
+							PrometheusCR: v1alpha2.TargetAllocatorPrometheusCR{
 								Enabled: true,
 							},
 						},
@@ -1371,12 +1371,8 @@ label_selector:
   app.kubernetes.io/managed-by: opentelemetry-operator
   app.kubernetes.io/part-of: opentelemetry
 prometheus_cr:
-  pod_monitor_selector:
-    matchlabels: {}
-    matchexpressions: []
-  service_monitor_selector:
-    matchlabels: {}
-    matchexpressions: []
+  pod_monitor_selector: null
+  service_monitor_selector: null
 `,
 					},
 				},
@@ -1409,7 +1405,7 @@ prometheus_cr:
 									"app.kubernetes.io/version":    "latest",
 								},
 								Annotations: map[string]string{
-									"opentelemetry-targetallocator-config/hash": "51477b182d2c9e7c0db27a2cbc9c7d35b24895b1cf0774d51a41b8d1753696ed",
+									"opentelemetry-targetallocator-config/hash": "59307aaa5652c8723f7803aa2d2b631389d1a0267444a4a8dc559878b5c4aa2c",
 								},
 							},
 							Spec: corev1.PodSpec{
@@ -1546,9 +1542,9 @@ prometheus_cr:
 						},
 						Mode:   "statefulset",
 						Config: goodConfig,
-						TargetAllocator: v1alpha1.OpenTelemetryTargetAllocator{
+						TargetAllocator: v1alpha2.TargetAllocatorEmbedded{
 							Enabled: true,
-							PrometheusCR: v1alpha1.OpenTelemetryTargetAllocatorPrometheusCR{
+							PrometheusCR: v1alpha2.TargetAllocatorPrometheusCR{
 								Enabled: true,
 							},
 							FilterStrategy: "relabel-config",
@@ -1772,12 +1768,8 @@ label_selector:
   app.kubernetes.io/managed-by: opentelemetry-operator
   app.kubernetes.io/part-of: opentelemetry
 prometheus_cr:
-  pod_monitor_selector:
-    matchlabels: {}
-    matchexpressions: []
-  service_monitor_selector:
-    matchlabels: {}
-    matchexpressions: []
+  pod_monitor_selector: null
+  service_monitor_selector: null
 `,
 					},
 				},
@@ -1810,7 +1802,7 @@ prometheus_cr:
 									"app.kubernetes.io/version":    "latest",
 								},
 								Annotations: map[string]string{
-									"opentelemetry-targetallocator-config/hash": "51477b182d2c9e7c0db27a2cbc9c7d35b24895b1cf0774d51a41b8d1753696ed",
+									"opentelemetry-targetallocator-config/hash": "59307aaa5652c8723f7803aa2d2b631389d1a0267444a4a8dc559878b5c4aa2c",
 								},
 							},
 							Spec: corev1.PodSpec{

controllers/reconcile_test.go

@@ -468,6 +468,8 @@ func TestOpenTelemetryCollectorReconciler_Reconcile(t *testing.T) {
 							taConfig["config"] = promConfig["config"]
 							taConfig["allocation_strategy"] = "consistent-hashing"
 							taConfig["filter_strategy"] = "relabel-config"
+							taConfig["pod_monitor_selector"] = map[string]string{}
+							taConfig["service_monitor_selector"] = map[string]string{}
 							taConfig["prometheus_cr"] = map[string]any{
 								"scrape_interval":          "30s",
 								"pod_monitor_selector":     &metav1.LabelSelector{},

internal/api/convert/v1alpha.go

@@ -18,6 +18,7 @@ import (
 	"errors"
 
 	"gopkg.in/yaml.v3"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
 	"github.com/open-telemetry/opentelemetry-operator/apis/v1alpha1"
 	"github.com/open-telemetry/opentelemetry-operator/apis/v1alpha2"
@@ -93,30 +94,7 @@ func V1Alpha1to2(in v1alpha1.OpenTelemetryCollector) (v1alpha2.OpenTelemetryColl
 	out.Spec.OpenTelemetryCommonFields.InitContainers = copy.Spec.InitContainers
 	out.Spec.OpenTelemetryCommonFields.AdditionalContainers = copy.Spec.AdditionalContainers
 
-	out.Spec.TargetAllocator.Replicas = copy.Spec.TargetAllocator.Replicas
-	out.Spec.TargetAllocator.NodeSelector = copy.Spec.TargetAllocator.NodeSelector
-	out.Spec.TargetAllocator.Resources = copy.Spec.TargetAllocator.Resources
-	out.Spec.TargetAllocator.AllocationStrategy = copy.Spec.TargetAllocator.AllocationStrategy
-	out.Spec.TargetAllocator.FilterStrategy = copy.Spec.TargetAllocator.FilterStrategy
-	out.Spec.TargetAllocator.ServiceAccount = copy.Spec.TargetAllocator.ServiceAccount
-	out.Spec.TargetAllocator.Image = copy.Spec.TargetAllocator.Image
-	out.Spec.TargetAllocator.Enabled = copy.Spec.TargetAllocator.Enabled
-	out.Spec.TargetAllocator.Affinity = copy.Spec.TargetAllocator.Affinity
-	out.Spec.TargetAllocator.PrometheusCR.Enabled = copy.Spec.TargetAllocator.PrometheusCR.Enabled
-	out.Spec.TargetAllocator.PrometheusCR.ScrapeInterval = copy.Spec.TargetAllocator.PrometheusCR.ScrapeInterval
-	out.Spec.TargetAllocator.PrometheusCR.PodMonitorSelector = copy.Spec.TargetAllocator.PrometheusCR.PodMonitorSelector
-	out.Spec.TargetAllocator.PrometheusCR.ServiceMonitorSelector = copy.Spec.TargetAllocator.PrometheusCR.ServiceMonitorSelector
-	out.Spec.TargetAllocator.SecurityContext = copy.Spec.TargetAllocator.SecurityContext
-	out.Spec.TargetAllocator.PodSecurityContext = copy.Spec.TargetAllocator.PodSecurityContext
-	out.Spec.TargetAllocator.TopologySpreadConstraints = copy.Spec.TargetAllocator.TopologySpreadConstraints
-	out.Spec.TargetAllocator.Tolerations = copy.Spec.TargetAllocator.Tolerations
-	out.Spec.TargetAllocator.Env = copy.Spec.TargetAllocator.Env
-	out.Spec.TargetAllocator.Observability = v1alpha1.ObservabilitySpec{
-		Metrics: v1alpha1.MetricsConfigSpec{
-			EnableMetrics: copy.Spec.TargetAllocator.Observability.Metrics.EnableMetrics,
-		},
-	}
-	out.Spec.TargetAllocator.PodDisruptionBudget = copy.Spec.TargetAllocator.PodDisruptionBudget
+	out.Spec.TargetAllocator = TargetAllocatorEmbedded(copy.Spec.TargetAllocator)
 
 	out.Spec.Mode = v1alpha2.Mode(copy.Spec.Mode)
 	out.Spec.UpgradeStrategy = v1alpha2.UpgradeStrategy(copy.Spec.UpgradeStrategy)
@@ -148,3 +126,42 @@ func V1Alpha1to2(in v1alpha1.OpenTelemetryCollector) (v1alpha2.OpenTelemetryColl
 
 	return out, nil
 }
+
+func TargetAllocatorEmbedded(in v1alpha1.OpenTelemetryTargetAllocator) v1alpha2.TargetAllocatorEmbedded {
+	out := v1alpha2.TargetAllocatorEmbedded{}
+	out.Replicas = in.Replicas
+	out.NodeSelector = in.NodeSelector
+	out.Resources = in.Resources
+	out.AllocationStrategy = v1alpha2.TargetAllocatorAllocationStrategy(in.AllocationStrategy)
+	out.FilterStrategy = v1alpha2.TargetAllocatorFilterStrategy(in.FilterStrategy)
+	out.ServiceAccount = in.ServiceAccount
+	out.Image = in.Image
+	out.Enabled = in.Enabled
+	out.Affinity = in.Affinity
+	out.PrometheusCR.Enabled = in.PrometheusCR.Enabled
+	out.PrometheusCR.ScrapeInterval = in.PrometheusCR.ScrapeInterval
+	out.SecurityContext = in.SecurityContext
+	out.PodSecurityContext = in.PodSecurityContext
+	out.TopologySpreadConstraints = in.TopologySpreadConstraints
+	out.Tolerations = in.Tolerations
+	out.Env = in.Env
+	out.Observability = v1alpha1.ObservabilitySpec{
+		Metrics: v1alpha1.MetricsConfigSpec{
+			EnableMetrics: in.Observability.Metrics.EnableMetrics,
+		},
+	}
+
+	out.PrometheusCR.PodMonitorSelector = &metav1.LabelSelector{
+		MatchLabels: in.PrometheusCR.PodMonitorSelector,
+	}
+	out.PrometheusCR.ServiceMonitorSelector = &metav1.LabelSelector{
+		MatchLabels: in.PrometheusCR.ServiceMonitorSelector,
+	}
+	if in.PodDisruptionBudget != nil {
+		out.PodDisruptionBudget = &v1alpha2.PodDisruptionBudgetSpec{
+			MinAvailable:   in.PodDisruptionBudget.MinAvailable,
+			MaxUnavailable: in.PodDisruptionBudget.MaxUnavailable,
+		}
+	}
+	return out
+}