Generate TargetAllocator CR from Collector CR

Author: swiatekm

apis/v1beta1/targetallocator_types.go

@@ -17,13 +17,17 @@
 package v1beta1
 
 import (
+	"encoding/json"
+
 	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"`
+	// CollectorSelector is the selector for Collector Pods the target allocator will allocate targets to.
+	CollectorSelector metav1.LabelSelector `json:"collectorSelector,omitempty"`
 	// 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
@@ -35,8 +39,13 @@ type TargetAllocatorSpec struct {
 	// +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.
+	// ScrapeConfigs define static Prometheus scrape configurations for the target allocator.
+	// To use dynamic configurations from ServiceMonitors and PodMonitors, see the PrometheusCR section.
+	// For the exact format, see https://prometheus.io/docs/prometheus/latest/configuration/configuration/#scrape_config.
+	// +optional
+	// +listType=atomic
+	ScrapeConfigs []ScrapeConfig `json:"scrapeConfigs,omitempty"`
+	// PrometheusCR defines the configuration for the retrieval of PrometheusOperator CRDs ( servicemonitor.monitoring.coreos.com/v1 and podmonitor.monitoring.coreos.com/v1 ).
 	// +optional
 	PrometheusCR TargetAllocatorPrometheusCR `json:"prometheusCR,omitempty"`
 }
@@ -82,6 +91,46 @@ type TargetAllocatorStatus struct {
 	Messages []string `json:"messages,omitempty"`
 }
 
+// ScrapeConfig is a Prometheus scrape config definition.
+type ScrapeConfig map[string]interface{}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *ScrapeConfig) DeepCopyInto(out *ScrapeConfig) {
+	*out = make(map[string]interface{}, len(*in))
+	for key, val := range *in {
+		(*out)[key] = val
+	}
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new ScrapeConfig.
+func (in *ScrapeConfig) DeepCopy() *ScrapeConfig {
+	if in == nil {
+		return nil
+	}
+	out := new(ScrapeConfig)
+	in.DeepCopyInto(out)
+	return out
+}
+
+var _ json.Marshaler = &ScrapeConfig{}
+var _ json.Unmarshaler = &ScrapeConfig{}
+
+// UnmarshalJSON implements an alternative parser for this field.
+func (c *ScrapeConfig) UnmarshalJSON(b []byte) error {
+	if err := json.Unmarshal(b, c); err != nil {
+		return err
+	}
+	return nil
+}
+
+// MarshalJSON specifies how to convert this object into JSON.
+func (c *ScrapeConfig) MarshalJSON() ([]byte, error) {
+	if c == nil {
+		return []byte("{}"), nil
+	}
+	return json.Marshal(c)
+}
+
 //+kubebuilder:object:root=true
 //+kubebuilder:subresource:status
 

apis/v1beta1/zz_generated.deepcopy.go

@@ -35,6 +35,7 @@ import (
 	"github.com/open-telemetry/opentelemetry-operator/internal/api/convert"
 	"github.com/open-telemetry/opentelemetry-operator/internal/config"
 	"github.com/open-telemetry/opentelemetry-operator/internal/manifests"
+	"github.com/open-telemetry/opentelemetry-operator/internal/manifests/collector"
 	collectorStatus "github.com/open-telemetry/opentelemetry-operator/internal/status/collector"
 	"github.com/open-telemetry/opentelemetry-operator/pkg/featuregate"
 )
@@ -62,14 +63,24 @@ func (r *OpenTelemetryCollectorReconciler) getParams(instance v1alpha1.OpenTelem
 	if err != nil {
 		return manifests.Params{}, err
 	}
-	return manifests.Params{
+	params := manifests.Params{
 		Config:   r.config,
 		Client:   r.Client,
 		OtelCol:  otelCol,
 		Log:      r.log,
 		Scheme:   r.scheme,
 		Recorder: r.recorder,
-	}, nil
+	}
+
+	// generate the target allocator CR from the collector CR
+	targetAllocator, err := collector.TargetAllocator(params)
+	if err != nil {
+		return params, err
+	}
+	if targetAllocator != nil {
+		params.TargetAllocator = *targetAllocator
+	}
+	return params, nil
 }
 
 // NewReconciler creates a new reconciler for OpenTelemetryCollector objects.

controllers/opentelemetrycollector_controller.go

@@ -0,0 +1,98 @@
+// 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 collector
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+
+	"github.com/open-telemetry/opentelemetry-operator/apis/v1beta1"
+	"github.com/open-telemetry/opentelemetry-operator/internal/manifests"
+	"github.com/open-telemetry/opentelemetry-operator/internal/manifests/manifestutils"
+	"github.com/open-telemetry/opentelemetry-operator/internal/manifests/targetallocator/adapters"
+)
+
+// TargetAllocator builds the TargetAllocator CR for the given instance.
+func TargetAllocator(params manifests.Params) (*v1beta1.TargetAllocator, error) {
+
+	taSpec := params.OtelCol.Spec.TargetAllocator
+	if !taSpec.Enabled {
+		return nil, nil
+	}
+
+	collectorSelector := metav1.LabelSelector{
+		MatchLabels: manifestutils.SelectorLabels(params.OtelCol.ObjectMeta, ComponentOpenTelemetryCollector),
+	}
+
+	configStr, err := params.OtelCol.Spec.Config.Yaml()
+	if err != nil {
+		return nil, err
+	}
+	scrapeConfigs, err := getScrapeConfigs(configStr)
+	if err != nil {
+		return nil, err
+	}
+
+	return &v1beta1.TargetAllocator{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:        params.OtelCol.Name,
+			Namespace:   params.OtelCol.Namespace,
+			Annotations: params.OtelCol.Annotations,
+			Labels:      params.OtelCol.Labels,
+		},
+		Spec: v1beta1.TargetAllocatorSpec{
+			OpenTelemetryCommonFields: v1beta1.OpenTelemetryCommonFields{
+				Replicas:                  taSpec.Replicas,
+				NodeSelector:              taSpec.NodeSelector,
+				Resources:                 taSpec.Resources,
+				ServiceAccount:            taSpec.ServiceAccount,
+				SecurityContext:           taSpec.SecurityContext,
+				PodSecurityContext:        taSpec.PodSecurityContext,
+				Image:                     taSpec.Image,
+				Affinity:                  taSpec.Affinity,
+				TopologySpreadConstraints: taSpec.TopologySpreadConstraints,
+				Tolerations:               taSpec.Tolerations,
+				Env:                       taSpec.Env,
+				PodAnnotations:            params.OtelCol.Spec.PodAnnotations,
+			},
+			CollectorSelector:  collectorSelector,
+			AllocationStrategy: taSpec.AllocationStrategy,
+			FilterStrategy:     taSpec.FilterStrategy,
+			ScrapeConfigs:      scrapeConfigs,
+			PrometheusCR:       taSpec.PrometheusCR,
+		},
+	}, nil
+}
+
+func getScrapeConfigs(otelcolConfig string) ([]v1beta1.ScrapeConfig, error) {
+	// Collector supports environment variable substitution, but the TA does not.
+	// TA Scrape Configs should have a single "$", as it does not support env var substitution
+	prometheusReceiverConfig, err := adapters.UnescapeDollarSignsInPromConfig(otelcolConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	scrapeConfigs, err := adapters.GetScrapeConfigsFromPromConfig(prometheusReceiverConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	v1beta1scrapeConfigs := make([]v1beta1.ScrapeConfig, len(scrapeConfigs))
+
+	for i, config := range scrapeConfigs {
+		v1beta1scrapeConfigs[i] = config
+	}
+
+	return v1beta1scrapeConfigs, nil
+}