Add TargetAllocator CRD (#2516)

apis/v1alpha2/allocation_strategy.go

@@ -0,0 +1,35 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v1alpha2
+
+type (
+	// TargetAllocatorAllocationStrategy represent a strategy Target Allocator uses to distribute targets to each collector
+	// +kubebuilder:validation:Enum=least-weighted;consistent-hashing
+	TargetAllocatorAllocationStrategy string
+	// TargetAllocatorFilterStrategy represent a filtering strategy for targets before they are assigned to collectors
+	// +kubebuilder:validation:Enum="";relabel-config
+	TargetAllocatorFilterStrategy string
+)
+
+const (
+	// TargetAllocatorAllocationStrategyLeastWeighted targets will be distributed to collector with fewer targets currently assigned.
+	TargetAllocatorAllocationStrategyLeastWeighted TargetAllocatorAllocationStrategy = "least-weighted"
+
+	// TargetAllocatorAllocationStrategyConsistentHashing targets will be consistently added to collectors, which allows a high-availability setup.
+	TargetAllocatorAllocationStrategyConsistentHashing TargetAllocatorAllocationStrategy = "consistent-hashing"
+
+	// TargetAllocatorFilterStrategyRelabelConfig targets will be consistently drops targets based on the relabel_config.
+	TargetAllocatorFilterStrategyRelabelConfig TargetAllocatorFilterStrategy = "consistent-hashing"
+)

apis/v1alpha2/targetallocator_types.go

@@ -0,0 +1,108 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +kubebuilder:skip
+
+package v1alpha2
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// TargetAllocatorSpec defines the desired state of TargetAllocator.
+type TargetAllocatorSpec struct {
+	// Common defines fields that are common to all OpenTelemetry CRD workloads.
+	OpenTelemetryCommonFields `json:",inline"`
+	// AllocationStrategy determines which strategy the target allocator should use for allocation.
+	// The current options are least-weighted and consistent-hashing. The default option 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
+	PrometheusCR TargetAllocatorPrometheusCR `json:"prometheusCR,omitempty"`
+}
+
+// TargetAllocatorPrometheusCR configures Prometheus CustomResource handling in the Target Allocator.
+type TargetAllocatorPrometheusCR struct {
+	// Enabled indicates whether to use a PrometheusOperator custom resources as targets or not.
+	// +optional
+	Enabled bool `json:"enabled,omitempty"`
+	// Default interval between consecutive scrapes. Intervals set in ServiceMonitors and PodMonitors override it.
+	//Equivalent to the same setting on the Prometheus CR.
+	//
+	// Default: "30s"
+	// +kubebuilder:default:="30s"
+	// +kubebuilder:validation:Format:=duration
+	ScrapeInterval *metav1.Duration `json:"scrapeInterval,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.
+	// +optional
+	PodMonitorSelector *metav1.LabelSelector `json:"podMonitorSelector,omitempty"`
+	// ServiceMonitors 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
+	// ServiceMonitor's meta labels. The requirements are ANDed.
+	// +optional
+	ServiceMonitorSelector *metav1.LabelSelector `json:"serviceMonitorSelector,omitempty"`
+}
+
+// TargetAllocatorStatus defines the observed state of Target Allocator.
+type TargetAllocatorStatus struct {
+	// Version of the managed Target Allocator (operand)
+	// +optional
+	Version string `json:"version,omitempty"`
+
+	// Image indicates the container image to use for the Target Allocator.
+	// +optional
+	Image string `json:"image,omitempty"`
+
+	// Messages about actions performed by the operator on this resource.
+	// +optional
+	// +listType=atomic
+	// Deprecated: use Kubernetes events instead.
+	Messages []string `json:"messages,omitempty"`
+}
+
+//+kubebuilder:object:root=true
+//+kubebuilder:subresource:status
+
+// TargetAllocator is the Schema for the targetallocators API.
+type TargetAllocator struct {
+	metav1.TypeMeta   `json:",inline"`
+	metav1.ObjectMeta `json:"metadata,omitempty"`
+
+	Spec   TargetAllocatorSpec   `json:"spec,omitempty"`
+	Status TargetAllocatorStatus `json:"status,omitempty"`
+}
+
+//+kubebuilder:object:root=true
+
+// TargetAllocatorList contains a list of TargetAllocator.
+type TargetAllocatorList struct {
+	metav1.TypeMeta `json:",inline"`
+	metav1.ListMeta `json:"metadata,omitempty"`
+	Items           []OpenTelemetryCollector `json:"items"`
+}
+
+func init() {
+	SchemeBuilder.Register(&TargetAllocator{}, &TargetAllocatorList{})
+}