Demo OpenTelemetry Operator

In this guide you’ll deploy an OpenTelemetry Collector using the OpenTelemetry Operator so collectors are managed as Kubernetes-native objects (Custom Resources). The operator is required for cluster-wide auto-instrumentation and simplifies lifecycle, upgrades, and configuration of collectors.

Quick Helm install

Add the Helm repo and install the operator quickly:

helm repo add open-telemetry https://open-telemetry.github.io/opentelemetry-helm-charts
helm install my-opentelemetry-operator open-telemetry/opentelemetry-operator \
  --set "manager.collectorImage.repository=otel/opentelemetry-collector-k8s" \
  --set admissionWebhooks.certManager.enabled=false \
  --set admissionWebhooks.autoGenerateCert.enabled=true

Environment sanity checks

Confirm your Kubernetes nodes and clean up any prior resources you no longer need:

kubectl get nodes

Example output:

NAME                STATUS   ROLES           AGE     VERSION
kind-control-plane  Ready    control-plane   41m     v1.33.1
kind-worker         Ready    <none>          41m     v1.33.1
kind-worker2        Ready    <none>          41m     v1.33.1

If you already have telemetry backends like Jaeger running you can keep them; this demo retains a Jaeger instance.

Install with a customized values.yaml

For more control, fetch the chart defaults, edit them, then install with your edited values.yaml:

helm show values open-telemetry/opentelemetry-operator > values.yaml
# edit values.yaml as needed (see TLS/webhook notes below)
helm install my-opentelemetry-operator open-telemetry/opentelemetry-operator -f values.yaml

A few top-level values (excerpt):

# values.yaml (excerpt)
namespaceOverride: ""
replicaCount: 1
revisionHistoryLimit: 10
nameOverride: ""

TLS / Admission webhook certificate options

The operator installs admission webhooks that require a TLS certificate trusted by the API server. You have three main options:

Option	Use case	Notes / link
cert-manager	Production or cluster-wide certificate management	Deploy `cert-manager` and set `admissionWebhooks.certManager.enabled: true`. See `cert-manager` docs: https://cert-manager.io/docs/
Operator auto-generate (recommended for demos)	Quick demos or local clusters	Let the operator generate a self-signed cert by enabling `admissionWebhooks.autoGenerateCert.enabled`.
Provide your own cert	Advanced / policy-controlled environments	Supply the webhook certificate from your own PKI and configure the operator accordingly.

If you don’t want to install cert-manager, set admissionWebhooks.certManager.enabled to false and admissionWebhooks.autoGenerateCert.enabled to true so the operator auto-creates a self-signed webhook certificate suitable for demos and local testing.

Use this values.yaml snippet to enable the operator’s auto-generated certificate:

admissionWebhooks:
  certManager:
    enabled: false
  autoGenerateCert:
    enabled: true
    recreate: true
    certPeriodDays: 365

Configure operator and collector images

Set the manager and default collector image repositories and tags in values.yaml as needed:

manager:
  image:
    repository: ghcr.io/open-telemetry/opentelemetry-operator/opentelemetry-operator
    tag: ""
    imagePullPolicy: IfNotPresent
  collectorImage:
    repository: ghcr.io/open-telemetry/opentelemetry-collector-releases/opentelemetry-collector-k8s
    tag: 0.137.0

Install (or upgrade) the operator with your edited values:

helm install my-opentelemetry-operator open-telemetry/opentelemetry-operator -f values.yaml

Example Helm output:

NAME: my-opentelemetry-operator
LAST DEPLOYED: Tue Oct 21 22:55:09 2025
NAMESPACE: default
STATUS: deployed
REVISION: 1
NOTES:
[WARNING] No resource limits or requests were set. Consider setting resource requests and limits via the `resources` field.

opentelemetry-operator has been installed. Check its status by running:
    kubectl --namespace default get pods -l "app.kubernetes.io/instance=my-opentelemetry-operator"

Verify the operator

Check deployments:

kubectl get deployment

Example output:

NAME                            READY   UP-TO-DATE   AVAILABLE   AGE
jaeger                          1/1     1            1           45m
my-opentelemetry-operator       1/1     1            1           15s

Note: this deployment is the operator controller — not a collector. The operator will create and reconcile OpenTelemetryCollector custom resources for you. The OpenTelemetry Operator chart documentation describes the webhook/TLS details in depth: https://github.com/open-telemetry/opentelemetry-helm-charts/tree/main/charts/opentelemetry-operator

The image shows a webpage from OpenTelemetry documentation discussing the configuration of the Operator Helm chart with a focus on TLS certificates and cert-manager usage in Kubernetes.

Creating a Collector via the Operator

Create a collector by applying an OpenTelemetryCollector CR. The CRD accepts the standard collector configuration (receivers, processors, exporters, service pipelines) and operator-specific fields such as mode (Deployment or DaemonSet) and upgrade settings. Example collector.yaml — a deployment-mode collector named my-collector that accepts OTLP, logs debug output, and forwards traces to an in-cluster Jaeger service:

apiVersion: opentelemetry.io/v1beta1
kind: OpenTelemetryCollector
metadata:
  name: my-collector
spec:
  mode: deployment
  config:
    receivers:
      otlp:
        protocols:
          grpc:
            endpoint: 0.0.0.0:4317
          http:
            endpoint: 0.0.0.0:4318

    processors:
      memory_limiter:
        check_interval: 1s
        limit_percentage: 75
        spike_limit_percentage: 15
      batch:
        send_batch_size: 10000
        timeout: 10s

    exporters:
      # NOTE: Prior to v0.86.0 use `logging` instead of `debug`.
      debug:
        verbosity: detailed

      otlp/jaeger:
        endpoint: jaeger-internal:4317
        tls:
          insecure: true

    service:
      pipelines:
        traces:
          receivers: [otlp]
          processors: [memory_limiter, batch]
          exporters: [debug, otlp/jaeger]

Apply the collector CR:

kubectl apply -f collector.yaml

Expected response:

opentelemetrycollector.opentelemetry.io/my-collector created

Check the collector CR, deployments and pods:

kubectl get opentelemetrycollector
kubectl get deployment
kubectl get pod

Example outputs:

# CR status (example)
NAME           MODE        VERSION   READY   AGE    IMAGE
my-collector   deployment  0.137.0   1/1     7s     ghcr.io/open-telemetry/opentelemetry-collector-releases/opentelemetry-collector-k8s:0.137.0  managed

# Deployments
NAME                           READY   UP-TO-DATE   AVAILABLE   AGE
jaeger                         1/1     1            1           53m
my-collector-collector         1/1     1            1           14s
my-opentelemetry-operator      1/1     1            1           7m54s

# Pods
NAME                                              READY   STATUS    RESTARTS   AGE
jaeger-75f7bdcc4-sr2v6                            1/1     Running   0          46m
my-collector-collector-dd46d98c6-kpg4n            1/1     Running   0          2m
my-opentelemetry-operator-77fcd686bd-54258        2/2     Running   0          9m

Services created by the operator

When the operator deploys a collector in deployment mode it creates ClusterIP Services so other pods can reach the collector by DNS (no need to use node IPs). Example kubectl get svc output (collector services highlighted):

kubectl get svc

Example output converted to a table for clarity:

NAME	TYPE	CLUSTER-IP	PORT(S)	AGE
jaeger-external	NodePort	10.96.224.52	16686:30007/TCP	54m
jaeger-internal	ClusterIP	10.96.11.34	4317/TCP,4318/TCP,14250/TCP,14268/TCP	54m
kubernetes	ClusterIP	10.96.0.1	443/TCP	54m
my-collector-collector	ClusterIP	10.96.73.32	4317/TCP,4318/TCP	47s
my-collector-collector-headless	ClusterIP	10.96.2.111	8888/TCP	47s
my-collector-collector-monitoring	ClusterIP	10.96.92.124	8443/TCP,8080/TCP	8m27s
my-opentelemetry-operator	ClusterIP	10.96.77.7	443/TCP	8m27s

Deploy an application that sends traces

Point your app at the collector service DNS (e.g. my-collector-collector) instead of a node IP. Example Deployment snippet:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
spec:
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
        - name: myapp
          image: sloppy-networks/traces-py
          env:
            - name: OTEL_EXPORTER_OTLP_ENDPOINT
              value: "http://my-collector-collector:4318"

Apply the app and verify pods:

kubectl apply -f app-deployment.yaml
kubectl get pod

Example pod listing showing the app starting:

NAME                                               READY   STATUS            RESTARTS   AGE
jaeger-75f7bdcc4-sr2v6                             1/1     Running           0          55m
my-collector-collector-dd46d98c6-kpg4n             1/1     Running           0          119s
my-opentelemetry-operator-77fcd686bd-54258         2/2     Running           0          9m39s
myapp-5d474bf94c-nz8c2                             0/1     ContainerCreating 0          3s

Check application logs to confirm spans are being sent and received by the collector. Example kubectl logs output from the sample app:

Span #1
Trace ID     : 7a13dcaa7590b979b4e88551c960d02d
Parent ID    : 27ff3b347e06fb2
ID           : 2f9d5516fdc33ee
Name         : process flight
Kind         : Internal
Start time   : 2025-10-22 05:05:04.274897701 +0000 UTC
End time     : 2025-10-22 05:05:04.316242576 +0000 UTC
Status code  : Unset
Status message:
Attributes:
  -> source: Str(jfk)
  -> dest: Str(lax)
  -> flight_number: Str(4427)
  -> airline: Str(delta)

Viewing traces in Jaeger

Open the Jaeger UI (NodePort, port-forward, or external URL) and search for your service. The UI should display traces forwarded from your application via the operator-managed collector.

The image shows the Jaeger UI displaying tracing data, with a list of trace results for a "flight-service" including their durations and timestamps. It includes a filter section for refining search criteria based on service, operation, and duration.

Conclusion

Using the OpenTelemetry Operator makes collectors Kubernetes-first: define an OpenTelemetryCollector CR with normal collector configuration, choose deployment mode (DaemonSet or Deployment), and let the operator manage lifecycle, upgrades, and reconciliations. This is especially helpful for cluster-wide auto-instrumentation and centralized collector management.

Links and references

OpenTelemetry Operator Helm Chart: https://github.com/open-telemetry/opentelemetry-helm-charts/tree/main/charts/opentelemetry-operator
cert-manager documentation: https://cert-manager.io/docs/
OpenTelemetry Collector releases: https://github.com/open-telemetry/opentelemetry-collector-releases
Jaeger project: https://www.jaegertracing.io/
Kubernetes documentation: https://kubernetes.io/docs/

Course Introduction

Observability Core Concepts

OpenTelemetry Core Concepts

Span Anatomy and Context Propagation

Instrumentation

Metrics Data Model

Recording Measurements

OTel Collector Foundations

OTel Collector Core Components

Transforming Telemetry – Pipeline Processing

OpenTelemetry in Kubernetes

OpenTelemetry Collector: Debugging, Operations, and Scaling

Extended Topics

Demo OpenTelemetry Operator

Quick Helm install

Environment sanity checks

Install with a customized values.yaml

TLS / Admission webhook certificate options

Configure operator and collector images

Verify the operator

Creating a Collector via the Operator

Services created by the operator

Deploy an application that sends traces

Viewing traces in Jaeger

Conclusion

Links and references

Watch Video

​Quick Helm install

​Environment sanity checks

​Install with a customized values.yaml

​TLS / Admission webhook certificate options

​Configure operator and collector images

​Verify the operator

​Creating a Collector via the Operator

​Services created by the operator

​Deploy an application that sends traces

​Viewing traces in Jaeger

​Conclusion

​Links and references

Watch Video

Quick Helm install

Environment sanity checks

Install with a customized values.yaml

TLS / Admission webhook certificate options

Configure operator and collector images

Verify the operator

Creating a Collector via the Operator

Services created by the operator

Deploy an application that sends traces

Viewing traces in Jaeger

Conclusion

Links and references