The OpenTelemetry Operator is an implementation of a Kubernetes Operator.
The operator manages:
- OpenTelemetry Collector
- auto-instrumentation of the workloads using OpenTelemetry instrumentation libraries
To install the operator in an existing cluster, make sure you have cert-manager installed and run:
kubectl apply -f https://github.com/open-telemetry/opentelemetry-operator/releases/latest/download/opentelemetry-operator.yamlOnce the opentelemetry-operator deployment is ready, create an OpenTelemetry Collector (otelcol) instance, like:
kubectl apply -f - <<EOF
apiVersion: opentelemetry.io/v1alpha1
kind: OpenTelemetryCollector
metadata:
name: simplest
spec:
config: |
receivers:
otlp:
protocols:
grpc:
http:
processors:
exporters:
logging:
service:
pipelines:
traces:
receivers: [otlp]
processors: []
exporters: [logging]
EOFWARNING: Until the OpenTelemetry Collector format is stable, changes may be required in the above example to remain compatible with the latest version of the OpenTelemetry Collector image being referenced.
This will create an OpenTelemetry Collector instance named simplest, exposing a jaeger-grpc port to consume spans from your instrumented applications and exporting those spans via logging, which writes the spans to the console (stdout) of the OpenTelemetry Collector instance that receives the span.
The config node holds the YAML that should be passed down as-is to the underlying OpenTelemetry Collector instances. Refer to the OpenTelemetry Collector documentation for a reference of the possible entries.
At this point, the Operator does not validate the contents of the configuration file: if the configuration is invalid, the instance will still be created but the underlying OpenTelemetry Collector might crash.
As noted above, the OpenTelemetry Collector format is continuing to evolve. However, a best-effort attempt is made to upgrade all managed OpenTelemetryCollector resources.
In certain scenarios, it may be desirable to prevent the operator from upgrading certain OpenTelemetryCollector resources. For example, when a resource is configured with a custom .Spec.Image, end users may wish to manage configuration themselves as opposed to having the operator upgrade it. This can be configured on a resource by resource basis with the exposed property .Spec.UpgradeStrategy.
By configuring a resource's .Spec.UpgradeStrategy to none, the operator will skip the given instance during the upgrade routine.
The default and only other acceptable value for .Spec.UpgradeStrategy is automatic.
The CustomResource for the OpenTelemetryCollector exposes a property named .Spec.Mode, which can be used to specify whether the collector should run as a DaemonSet, Sidecar, or Deployment (default). Look at this sample for reference.
A sidecar with the OpenTelemetry Collector can be injected into pod-based workloads by setting the pod annotation sidecar.opentelemetry.io/inject to either "true", or to the name of a concrete OpenTelemetryCollector from the same namespace, like in the following example:
kubectl apply -f - <<EOF
apiVersion: opentelemetry.io/v1alpha1
kind: OpenTelemetryCollector
metadata:
name: sidecar-for-my-app
spec:
mode: sidecar
config: |
receivers:
jaeger:
protocols:
grpc:
otlp:
protocols:
grpc:
http:
processors:
exporters:
logging:
service:
pipelines:
traces:
receivers: [otlp, jaeger]
processors: []
exporters: [logging]
EOF
kubectl apply -f - <<EOF
apiVersion: v1
kind: Pod
metadata:
name: myapp
annotations:
sidecar.opentelemetry.io/inject: "true"
spec:
containers:
- name: myapp
image: jaegertracing/vertx-create-span:operator-e2e-tests
ports:
- containerPort: 8080
protocol: TCP
EOFWhen there are multiple OpenTelemetryCollector resources with a mode set to Sidecar in the same namespace, a concrete name should be used. When there's only one Sidecar instance in the same namespace, this instance is used when the annotation is set to "true".
The annotation value can come either from the namespace, or from the pod. The most specific annotation wins, in this order:
- the pod annotation is used when it's set to a concrete instance name or to
"false" - namespace annotation is used when the pod annotation is either absent or set to
"true", and the namespace is set to a concrete instance or to"false"
When using a pod-based workload, such as Deployment or Statefulset, make sure to add the annotation to the PodTemplate part. Like:
kubectl apply -f - <<EOF
apiVersion: apps/v1
kind: Deployment
metadata:
name: my-app
labels:
app: my-app
annotations:
sidecar.opentelemetry.io/inject: "true" # WRONG
spec:
selector:
matchLabels:
app: my-app
replicas: 1
template:
metadata:
labels:
app: my-app
annotations:
sidecar.opentelemetry.io/inject: "true" # CORRECT
spec:
containers:
- name: myapp
image: jaegertracing/vertx-create-span:operator-e2e-tests
ports:
- containerPort: 8080
protocol: TCP
EOFThe operator can inject and configure OpenTelemetry auto-instrumentation libraries. Currently Java, NodeJS and Python are supported.
To use auto-instrumentation, configure an Instrumentation resource with the configuration for the SDK and instrumentation.
kubectl apply -f - <<EOF
apiVersion: opentelemetry.io/v1alpha1
kind: Instrumentation
metadata:
name: my-instrumentation
spec:
exporter:
endpoint: http://otel-collector:4317
propagators:
- tracecontext
- baggage
- b3
sampler:
type: parentbased_traceidratio
argument: "0.25"
EOFThe above CR can be queried by kubectl get otelinst.
Then add an annotation to a pod to enable injection. The annotation can be added to a namespace, so that all pods within that namespace wil get instrumentation, or by adding the annotation to individual PodSpec objects, available as part of Deployment, Statefulset, and other resources.
Java:
instrumentation.opentelemetry.io/inject-java: "true"NodeJS:
instrumentation.opentelemetry.io/inject-nodejs: "true"Python:
instrumentation.opentelemetry.io/inject-python: "true"The possible values for the annotation can be
"true"- inject andInstrumentationresource from the namespace."my-instrumentation"- name ofInstrumentationCR instance."false"- do not inject
The OpenTelemetry Operator follows the same versioning as the operand (OpenTelemetry Collector) up to the minor part of the version. For example, the OpenTelemetry Operator v0.18.1 tracks OpenTelemetry Collector 0.18.0. The patch part of the version indicates the patch level of the operator itself, not that of OpenTelemetry Collector. Whenever a new patch version is released for OpenTelemetry Collector, we'll release a new patch version of the operator.
By default, the OpenTelemetry Operator ensures consistent versioning between itself and the managed OpenTelemetryCollector resources. That is, if the OpenTelemetry Operator is based on version 0.40.0, it will create resources with an underlying OpenTelemetry Collector at version 0.40.0.
When a custom Spec.Image is used with an OpenTelemetryCollector resource, the OpenTelemetry Operator will not manage this versioning and upgrading. In this scenario, it is best practice that the OpenTelemetry Operator version should match the underlying core version. Given a OpenTelemetryCollector resource with a Spec.Image configured to a custom image based on underlying OpenTelemetry Collector at version 0.40.0, it is recommended that the OpenTelemetry Operator is kept at version 0.40.0.
We strive to be compatible with the widest range of Kubernetes versions as possible, but some changes to Kubernetes itself require us to break compatibility with older Kubernetes versions, be it because of code incompatibilities, or in the name of maintainability.
Our promise is that we'll follow what's common practice in the Kubernetes world and support N-2 versions, based on the release date of the OpenTelemetry Operator.
For instance, when we released v0.27.0, the latest Kubernetes version was v1.21.1. As such, the minimum version of Kubernetes we support for OpenTelemetry Operator v0.27.0 is v1.19 and we tested it with up to 1.21.
We use cert-manager for some features of this operator and the third column shows the versions of the cert-manager that are known to work with this operator's versions.
The OpenTelemetry Operator might work on versions outside of the given range, but when opening new issues, please make sure to test your scenario on a supported version.
| OpenTelemetry Operator | Kubernetes | Cert-Manager |
|---|---|---|
| v0.42.0 | v1.21 to v1.23 | 1.6.1 |
| v0.41.1 | v1.21 to v1.23 | 1.6.1 |
| v0.41.0 | v1.20 to v1.22 | 1.6.1 |
| v0.40.0 | v1.20 to v1.22 | 1.6.1 |
| v0.39.0 | v1.20 to v1.22 | 1.6.1 |
| v0.38.0 | v1.20 to v1.22 | 1.6.1 |
| v0.37.1 | v1.20 to v1.22 | v1.4.0 to v1.6.1 |
| v0.37.0 | v1.20 to v1.22 | v1.4.0 to v1.5.4 |
| v0.36.0 | v1.20 to v1.22 | v1.4.0 to v1.5.4 |
| v0.35.0 | v1.20 to v1.22 | v1.4.0 to v1.5.4 |
| v0.34.0 | v1.20 to v1.22 | v1.4.0 to v1.5.4 |
| v0.33.0 | v1.20 to v1.22 | v1.4.0 to v1.5.4 |
| v0.32.0 (skipped) | n/a | n/a |
| v0.31.0 | v1.19 to v1.21 | v1.4.0 to v1.5.4 |
| v0.30.0 | v1.19 to v1.21 | v1.4.0 to v1.5.4 |
| v0.29.0 | v1.19 to v1.21 | v1.4.0 to v1.5.4 |
| v0.28.0 | v1.19 to v1.21 | v1.4.0 to v1.5.4 |
| v0.27.0 | v1.19 to v1.21 | v1.4.0 to v1.5.4 |
Please see CONTRIBUTING.md.
Approvers (@open-telemetry/operator-approvers):
Maintainers (@open-telemetry/operator-maintainers):
- @open-telemetry/collector-maintainers
- Juraci Paixão Kröhling, Grafana Labs
- Vineeth Pothulapati, Timescale
Learn more about roles in the community repository.
Thanks to all the people who already contributed!