Add initial support for auto-instrumentation (#464)

* Initial support for auto-instrumentation

Signed-off-by: Pavol Loffay <p.loffay@gmail.com>

* fix

Signed-off-by: Pavol Loffay <p.loffay@gmail.com>

* Fix bundle

Signed-off-by: Pavol Loffay <p.loffay@gmail.com>

* Add docs

Signed-off-by: Pavol Loffay <p.loffay@gmail.com>

* make a nonsense change

Signed-off-by: Pavol Loffay <p.loffay@gmail.com>

* Add link

Signed-off-by: Pavol Loffay <p.loffay@gmail.com>

README.md

@@ -5,11 +5,14 @@
 
 The OpenTelemetry Operator is an implementation of a [Kubernetes Operator](https://coreos.com/operators/).
 
-At this point, it has [OpenTelemetry Collector](https://github.com/open-telemetry/opentelemetry-collector) as the only managed component.
+The operator manages:
+* [OpenTelemetry Collector](https://github.com/open-telemetry/opentelemetry-collector)
+* auto-instrumentation of the workloads using OpenTelemetry instrumentation libraries
 
 ## Documentation
 
 * [OpenTelemetryCollector Custom Resource Specification](./docs/otelcol_cr_spec.md)
+* [Instrumentation Custom Resource Specification](./docs/otelinst_cr_spec.md)
 
 ## Getting started
 
@@ -151,6 +154,46 @@ spec:
 EOF
 ```
 
+### OpenTelemetry auto-instrumentation injection
+
+The operator can inject and configure OpenTelemetry auto-instrumentation libraries. At this moment, the operator can inject only
+OpenTelemetry [Java auto-instrumentation](https://github.com/open-telemetry/opentelemetry-java-instrumentation).
+
+The injection of the Java agent can be enabled by adding an annotation to the namespace, so that all pods within that
+namespace will get the instrumentation, or by adding the annotation to individual PodSpec objects, available as part
+of Deployment, Statefulset, and other resources.
+
+```console
+instrumentation.opentelemetry.io/inject-java: "true"
+```
+
+The value can be 
+* `false` - do not inject
+* `true` - inject
+* `java-instrumentation` - name of `Instrumentation` CR instance.
+
+In the addition to the annotation the following `CR` has to be created. The `Instrumentation`
+provides configuration for OpenTelemetry SDK and auto-instrumentation.
+
+```yaml
+kubectl apply -f - <<EOF
+apiVersion: opentelemetry.io/v1alpha1
+kind: Instrumentation
+metadata:
+  name: java-instrumentation
+spec:
+  exporter:
+    endpoint: http://otel-collector:4318
+  java:
+    image: ghcr.io/pavolloffay/otel-javaagent:1.5.3 # <1>
+EOF
+```
+
+1. Container image with [OpenTelemetry Java auto-instrumentation](https://github.com/open-telemetry/opentelemetry-java-instrumentation). 
+   The image has to contain Java agent JAR `/javaagent.jar` and the JAR is copied to a shared volume mounted to the application container.
+
+The above CR can be queried by `kubectl get otelinst`.
+
 ## Compatibility matrix
 
 ### OpenTelemetry Operator vs. OpenTelemetry Collector

api/instrumentation/v1alpha1/groupversion_info.go

@@ -0,0 +1,34 @@
+// 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 v1alpha1 contains API Schema definitions for the core v1alpha1 API group.
+// +kubebuilder:object:generate=true
+// +groupName=opentelemetry.io
+package v1alpha1
+
+import (
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"sigs.k8s.io/controller-runtime/pkg/scheme"
+)
+
+var (
+	// GroupVersion is group version used to register these objects.
+	GroupVersion = schema.GroupVersion{Group: "opentelemetry.io", Version: "v1alpha1"}
+
+	// SchemeBuilder is used to add go types to the GroupVersionKind scheme.
+	SchemeBuilder = &scheme.Builder{GroupVersion: GroupVersion}
+
+	// AddToScheme adds the types in this group-version to the given scheme.
+	AddToScheme = SchemeBuilder.AddToScheme
+)

api/instrumentation/v1alpha1/instrumentation_types.go

@@ -0,0 +1,79 @@
+// 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 v1alpha1
+
+import metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+
+// InstrumentationSpec defines the desired state of OpenTelemetry SDK and instrumentation.
+type InstrumentationSpec struct {
+	// Exporter defines exporter configuration.
+	// +optional
+	// +operator-sdk:gen-csv:customresourcedefinitions.specDescriptors=true
+	Exporter `json:"exporter,omitempty"`
+
+	// Java defines configuration for java auto-instrumentation.
+	// +optional
+	// +operator-sdk:gen-csv:customresourcedefinitions.specDescriptors=true
+	Java JavaSpec `json:"java,omitempty"`
+}
+
+// JavaSpec defines Java SDK and instrumentation configuration.
+type JavaSpec struct {
+	// Image is a container image with javaagent JAR.
+	// +optional
+	// +operator-sdk:gen-csv:customresourcedefinitions.specDescriptors=true
+	Image string `json:"image,omitempty"`
+}
+
+// Exporter defines OTLP exporter configuration.
+type Exporter struct {
+	// Endpoint is address of the collector with OTLP endpoint.
+	// +optional
+	// +operator-sdk:gen-csv:customresourcedefinitions.specDescriptors=true
+	Endpoint string `json:"endpoint,omitempty"`
+}
+
+// InstrumentationStatus defines status of the instrumentation.
+type InstrumentationStatus struct {
+}
+
+// +kubebuilder:object:root=true
+// +kubebuilder:resource:shortName=otelinst;otelinsts
+// +kubebuilder:subresource:status
+// +kubebuilder:printcolumn:name="Age",type="date",JSONPath=".metadata.creationTimestamp"
+// +operator-sdk:csv:customresourcedefinitions:displayName="OpenTelemetry Instrumentation"
+
+// Instrumentation is the spec for OpenTelemetry instrumentation.
+// nolint: maligned
+type Instrumentation struct {
+	metav1.TypeMeta   `json:",inline"`
+	metav1.ObjectMeta `json:"metadata,omitempty"`
+
+	Spec   InstrumentationSpec   `json:"spec,omitempty"`
+	Status InstrumentationStatus `json:"status,omitempty"`
+}
+
+// +kubebuilder:object:root=true
+
+// InstrumentationList contains a list of Instrumentation.
+type InstrumentationList struct {
+	metav1.TypeMeta `json:",inline"`
+	metav1.ListMeta `json:"metadata,omitempty"`
+	Items           []Instrumentation `json:"items"`
+}
+
+func init() {
+	SchemeBuilder.Register(&Instrumentation{}, &InstrumentationList{})
+}

bundle/manifests/opentelemetry-operator.clusterserviceversion.yaml

@@ -31,6 +31,9 @@ spec:
   apiservicedefinitions: {}
   customresourcedefinitions:
     owned:
+    - kind: Instrumentation
+      name: instrumentations.opentelemetry.io
+      version: v1alpha1
     - kind: OpenTelemetryCollector
       name: opentelemetrycollectors.opentelemetry.io
       version: v1alpha1
@@ -146,6 +149,14 @@ spec:
           - get
           - list
           - update
+        - apiGroups:
+          - opentelemetry.io
+          resources:
+          - instrumentations
+          verbs:
+          - get
+          - list
+          - watch
         - apiGroups:
           - opentelemetry.io
           resources: