Use both collector selector formats in ta config

This is to keep backwards compatibility with older target allocator versions, which makes upgrades easier.
open-telemetry · Jan 8, 2024 · 803b7f2 · 803b7f2
1 parent a0af833
commit 803b7f2
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Showing 8 changed files with 55 additions and 18 deletions.
diff --git a/.chloggen/feat_targetallocator-selector.yaml b/.chloggen/feat_targetallocator-selector.yaml
@@ -13,4 +13,6 @@ issues: [2422]
 # (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: This is a breaking change only for users of standalone target allocator. Operator users are unaffected.
+subtext: |
+  This is a breaking change only for users of standalone target allocator. Operator users are unaffected.
+  The operator is still compatible with previous target allocator versions, and will be for the next 3 releases.
diff --git a/cmd/otel-allocator/config/config.go b/cmd/otel-allocator/config/config.go
@@ -40,17 +40,17 @@ 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:"-"`
-	CollectorSelector      metav1.LabelSelector `yaml:"collector_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:"-"`
+	CollectorSelector      *metav1.LabelSelector `yaml:"collector_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"`
 }
 
 type PrometheusCRConfig struct {

diff --git a/cmd/otel-allocator/config/config_test.go b/cmd/otel-allocator/config/config_test.go
@@ -45,7 +45,7 @@ func TestLoad(t *testing.T) {
 				file: "./testdata/config_test.yaml",
 			},
 			want: Config{
-				CollectorSelector: metav1.LabelSelector{
+				CollectorSelector: &metav1.LabelSelector{
 					MatchLabels: map[string]string{
 						"app.kubernetes.io/instance":   "default.test",
 						"app.kubernetes.io/managed-by": "opentelemetry-operator",
@@ -111,7 +111,7 @@ func TestLoad(t *testing.T) {
 				file: "./testdata/pod_service_selector_test.yaml",
 			},
 			want: Config{
-				CollectorSelector: metav1.LabelSelector{
+				CollectorSelector: &metav1.LabelSelector{
 					MatchLabels: map[string]string{
 						"app.kubernetes.io/instance":   "default.test",
 						"app.kubernetes.io/managed-by": "opentelemetry-operator",

diff --git a/cmd/otel-allocator/main.go b/cmd/otel-allocator/main.go
@@ -149,7 +149,7 @@ func main() {
 		})
 	runGroup.Add(
 		func() error {
-			err := collectorWatcher.Watch(ctx, &cfg.CollectorSelector, allocator.SetCollectors)
+			err := collectorWatcher.Watch(ctx, cfg.CollectorSelector, allocator.SetCollectors)
 			setupLog.Info("Collector watcher exited")
 			return err
 		},

diff --git a/controllers/builder_test.go b/controllers/builder_test.go
@@ -1340,6 +1340,11 @@ config:
       source_labels:
       - __meta_service_name
       target_label: instance
+label_selector:
+  app.kubernetes.io/component: opentelemetry-collector
+  app.kubernetes.io/instance: test.test
+  app.kubernetes.io/managed-by: opentelemetry-operator
+  app.kubernetes.io/part-of: opentelemetry
 `,
 					},
 				},
@@ -1372,7 +1377,7 @@ config:
 									"app.kubernetes.io/version":    "latest",
 								},
 								Annotations: map[string]string{
-									"opentelemetry-targetallocator-config/hash": "40afbbdb738923bf9cb4a117648cd86030cc5b748601d19120226eb1ee74c91a",
+									"opentelemetry-targetallocator-config/hash": "20c09760c240d08287ff05bd2375985220b577d938e82efd85467e17174690e0",
 								},
 							},
 							Spec: corev1.PodSpec{
@@ -1724,6 +1729,11 @@ config:
       source_labels:
       - __meta_service_name
       target_label: instance
+label_selector:
+  app.kubernetes.io/component: opentelemetry-collector
+  app.kubernetes.io/instance: test.test
+  app.kubernetes.io/managed-by: opentelemetry-operator
+  app.kubernetes.io/part-of: opentelemetry
 `,
 					},
 				},
@@ -1756,7 +1766,7 @@ config:
 									"app.kubernetes.io/version":    "latest",
 								},
 								Annotations: map[string]string{
-									"opentelemetry-targetallocator-config/hash": "40afbbdb738923bf9cb4a117648cd86030cc5b748601d19120226eb1ee74c91a",
+									"opentelemetry-targetallocator-config/hash": "20c09760c240d08287ff05bd2375985220b577d938e82efd85467e17174690e0",
 								},
 							},
 							Spec: corev1.PodSpec{

diff --git a/controllers/reconcile_test.go b/controllers/reconcile_test.go
@@ -451,6 +451,12 @@ func TestOpenTelemetryCollectorReconciler_Reconcile(t *testing.T) {
 									"app.kubernetes.io/part-of":    "opentelemetry",
 								},
 							}
+							taConfig["label_selector"] = map[string]string{
+								"app.kubernetes.io/instance":   "default.test",
+								"app.kubernetes.io/managed-by": "opentelemetry-operator",
+								"app.kubernetes.io/component":  "opentelemetry-collector",
+								"app.kubernetes.io/part-of":    "opentelemetry",
+							}
 							taConfig["config"] = promConfig["config"]
 							taConfig["allocation_strategy"] = "least-weighted"
 							taConfig["prometheus_cr"] = map[string]string{

diff --git a/internal/manifests/targetallocator/configmap.go b/internal/manifests/targetallocator/configmap.go
@@ -44,9 +44,13 @@ func ConfigMap(params manifests.Params) (*corev1.ConfigMap, error) {
 
 	taConfig := make(map[interface{}]interface{})
 	prometheusCRConfig := make(map[interface{}]interface{})
+	collectorSelectorLabels := manifestutils.SelectorLabels(params.OtelCol.ObjectMeta, collector.ComponentOpenTelemetryCollector)
 	taConfig["collector_selector"] = map[string]any{
-		"matchlabels": manifestutils.SelectorLabels(params.OtelCol.ObjectMeta, collector.ComponentOpenTelemetryCollector),
+		"matchlabels": collectorSelectorLabels,
 	}
+	// The below instruction is here for compatibility with the previous target allocator version
+	// TODO: Drop it after 3 more versions
+	taConfig["label_selector"] = collectorSelectorLabels
 	// We only take the "config" from the returned object, if it's present
 	if prometheusConfig, ok := prometheusReceiverConfig["config"]; ok {
 		taConfig["config"] = prometheusConfig

diff --git a/internal/manifests/targetallocator/configmap_test.go b/internal/manifests/targetallocator/configmap_test.go
@@ -54,6 +54,11 @@ config:
     - targets:
       - 0.0.0.0:8888
       - 0.0.0.0:9999
+label_selector:
+  app.kubernetes.io/component: opentelemetry-collector
+  app.kubernetes.io/instance: default.my-instance
+  app.kubernetes.io/managed-by: opentelemetry-operator
+  app.kubernetes.io/part-of: opentelemetry
 `,
 		}
 		instance := collectorInstance()
@@ -91,6 +96,11 @@ config:
     - targets:
       - 0.0.0.0:8888
       - 0.0.0.0:9999
+label_selector:
+  app.kubernetes.io/component: opentelemetry-collector
+  app.kubernetes.io/instance: default.my-instance
+  app.kubernetes.io/managed-by: opentelemetry-operator
+  app.kubernetes.io/part-of: opentelemetry
 pod_monitor_selector:
   release: my-instance
 service_monitor_selector:
@@ -138,6 +148,11 @@ config:
     - targets:
       - 0.0.0.0:8888
       - 0.0.0.0:9999
+label_selector:
+  app.kubernetes.io/component: opentelemetry-collector
+  app.kubernetes.io/instance: default.my-instance
+  app.kubernetes.io/managed-by: opentelemetry-operator
+  app.kubernetes.io/part-of: opentelemetry
 prometheus_cr:
   scrape_interval: 30s
 `,