Adding Additional Containers to the Collector spec

.chloggen/1987-adding-support-for-sidecar-containers.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: operator
+
+# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add `AdditionalContainers` to the collector spec allowing to configure sidecar containers. This only applies to Deployment/StatefulSet/DeamonSet deployment modes of the collector.
+
+# One or more tracking issues related to the change
+issues: [1987]
+
+# (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:

apis/v1alpha1/opentelemetrycollector_types.go

@@ -213,6 +213,22 @@ type OpenTelemetryCollectorSpec struct {
 	// +optional
 	InitContainers []v1.Container `json:"initContainers,omitempty"`
 
+	// AdditionalContainers allows injecting additional containers into the Collector's pod definition.
+	// These sidecar containers can be used for authentication proxies, log shipping sidecars, agents for shipping
+	// metrics to their cloud, or in general sidecars that do not support automatic injection. This option only
+	// applies to Deployment, DaemonSet, and StatefulSet deployment modes of the collector. It does not apply to the sidecar
+	// deployment mode. More info about sidecars:
+	// https://kubernetes.io/docs/tasks/configure-pod-container/share-process-namespace/
+	//
+	// Container names managed by the operator:
+	// * `otc-container`
+	//
+	// Overriding containers managed by the operator is outside the scope of what the maintainers will support and by
+	// doing so, you wil accept the risk of it breaking things.
+	//
+	// +optional
+	AdditionalContainers []v1.Container `json:"additionalContainers,omitempty"`
+
 	// ObservabilitySpec defines how telemetry data gets handled.
 	//
 	// +optional

apis/v1alpha1/opentelemetrycollector_webhook.go

@@ -155,6 +155,10 @@ func (r *OpenTelemetryCollector) validateCRDSpec() error {
 		return fmt.Errorf("the OpenTelemetry Collector mode is set to %s, which does not support the attribute 'affinity'", r.Spec.Mode)
 	}
 
+	if r.Spec.Mode == ModeSidecar && len(r.Spec.AdditionalContainers) > 0 {
+		return fmt.Errorf("the OpenTelemetry Collector mode is set to %s, which does not support the attribute 'AdditionalContainers'", r.Spec.Mode)
+	}
+
 	// validate target allocation
 	if r.Spec.TargetAllocator.Enabled && r.Spec.Mode != ModeStatefulSet {
 		return fmt.Errorf("the OpenTelemetry Collector mode is set to %s, which does not support the target allocation deployment", r.Spec.Mode)

apis/v1alpha1/opentelemetrycollector_webhook_test.go

@@ -605,6 +605,20 @@ func TestOTELColValidatingWebhook(t *testing.T) {
 			},
 			expectedErr: "the OpenTelemetry Spec LivenessProbe TerminationGracePeriodSeconds configuration is incorrect",
 		},
+		{
+			name: "invalid AdditionalContainers",
+			otelcol: OpenTelemetryCollector{
+				Spec: OpenTelemetryCollectorSpec{
+					Mode: ModeSidecar,
+					AdditionalContainers: []v1.Container{
+						{
+							Name: "test",
+						},
+					},
+				},
+			},
+			expectedErr: "the OpenTelemetry Collector mode is set to sidecar, which does not support the attribute 'AdditionalContainers'",
+		},
 	}
 
 	for _, test := range tests {

bundle/manifests/opentelemetry-operator.clusterserviceversion.yaml

@@ -31,7 +31,7 @@ metadata:
     categories: Logging & Tracing
     certified: "false"
     containerImage: ghcr.io/open-telemetry/opentelemetry-operator/opentelemetry-operator
-    createdAt: "2023-08-08T13:26:23Z"
+    createdAt: "2023-08-09T22:53:11Z"
     description: Provides the OpenTelemetry components, including the Collector
     operators.operatorframework.io/builder: operator-sdk-v1.29.0
     operators.operatorframework.io/project_layout: go.kubebuilder.io/v3

config/manager/kustomization.yaml

@@ -1,2 +1,8 @@
 resources:
 - manager.yaml
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+images:
+- name: controller
+  newName: ghcr.io/matt/opentelemetry-operator/opentelemetry-operator
+  newTag: 0.82.0-9-g6f4246c