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Open Telemetry quick start

OpenTelemetry is a CNCF (Cloud Native Computing Foundation) framework for observability. It enables your microservices to provide metrics, logs and traces.

Kubewarden's components using the OpenTelemetry SDK, report data to an OpenTelemetry collector -- called the agent.

This guide explains how to deploy the OpenTelemetry collector in sidecar mode by using the official Kubernetes Helm chart.

This is a simple deployment pattern using OpenTelemetry. Its final setup looks like this:

  • Each Pod of the Kubewarden stack (Policy Server, Controller) has an OpenTelemetry sidecar.
  • The sidecar receives tracing and monitoring information from the Kubewarden component via the OpenTelemetry Protocol (OTLP)
  • The OpenTelemetry collector:
    • Sends the trace events to a central Jaeger instance
    • Exposes Prometheus metrics on a specific port

The Kubewarden Helm chart doesn't cover all the possible deployment scenarios of the OpenTelemetry collector. It's also possible to configure Kubewarden to send data to an OpenTelemetry collector deployed by the user. Documentation for that scenario is in the custom OpenTelemetry guide.

You first deploy OpenTelemetry in a Kubernetes cluster, so you can use it in the following sections addressing tracing and metrics.

Setting up a Kubernetes cluster​

This section has step-by-step instructions to create a Kubernetes cluster with an ingress controller enabled.

Feel free to skip this section if you already have a Kubernetes cluster where you can define Ingress resources.

You can create a testing Kubernetes cluster using minikube.

Minikube has many backends, for this case you can use the kvm2 driver which relies on libvirt.

Assuming libvirtd is correctly running on your machine, issue the following command:

minikube start --driver=kvm2

The command produces output similar to the following one:

$ minikube start --driver=kvm2
😄  minikube v1.23.2 on Opensuse-Leap 15.3
✨  Using the kvm2 driver based on user configuration
👍  Starting control plane node minikube in cluster minikube
🔥  Creating kvm2 VM (CPUs=2, Memory=6000MB, Disk=20000MB) ...
🐳  Preparing Kubernetes v1.22.2 on Docker 20.10.8 ...
    ▪ Generating certificates and keys ...
    ▪ Booting up control plane ...
    ▪ Configuring RBAC rules ...
🔎  Verifying Kubernetes components...
    ▪ Using image gcr.io/k8s-minikube/storage-provisioner:v5
🌟  Enabled addons: storage-provisioner, default-storageclass
🏄  Done! kubectl is now configured to use "minikube" cluster and "default" namespace by default

Now you need to enable the Ingress addon:

minikube addons enable ingress

This produces an output similar to the following one:

$ minikube addons enable ingress
    ▪ Using image registry.k8s.io/ingress-nginx/kube-webhook-certgen:v1.0
    ▪ Using image registry.k8s.io/ingress-nginx/controller:v1.0.0-beta.3
    ▪ Using image registry.k8s.io/ingress-nginx/kube-webhook-certgen:v1.0
🔎  Verifying ingress addon...
🌟  The 'ingress' addon is enabled

Install OpenTelemetry​

You use the OpenTelemetry Operator to manage the automatic injection of the OpenTelemetry Collector sidecar into the PolicyServer pod.

The OpenTelemetry Operator requires installation of cert-manager in the cluster.

At the time of writing (2022-06-21), only specific versions of OpenTelemetry are compatible with Cert Manager, see the compatibility chart.

You should install the latest cert-manager Helm chart:

note

At time of writing (2024-07-17) the latest cert-manager chart version is v1.15.1

helm repo add jetstack https://charts.jetstack.io

helm install --wait \
    --namespace cert-manager \
    --create-namespace \
    --set crds.enabled=true \
    --version 1.15.1 \
    cert-manager jetstack/cert-manager

Once cert-manager is running, you can install the OpenTelemetry operator Helm chart:

note

At the time of writing (2024-11-11) the latest OpenTelemetry operator chart version is 0.65.0

helm repo add open-telemetry https://open-telemetry.github.io/opentelemetry-helm-charts

helm install --wait \
  --namespace open-telemetry \
  --create-namespace \
  --version 0.65.0 \
  --set "manager.collectorImage.repository=otel/opentelemetry-collector-contrib" \
  my-opentelemetry-operator open-telemetry/opentelemetry-operator

OpenTelemetry integration​

You can now move to the next chapters to enable application metrics (via Prometheus integration) and application tracing (via Jaeger integration).