Using Red Hat OpenShift distributed tracing - Tracing | Observability

You can use Red Hat OpenShift distributed tracing with OpenShift Serverless to monitor and troubleshoot serverless applications.

Using Red Hat OpenShift distributed tracing to enable distributed tracing

Red Hat OpenShift distributed tracing is made up of several components that work together to collect, store, and display tracing data.

Prerequisites

You have access to an OpenShift Container Platform account with cluster administrator access.
You have installed Red Hat OpenShift distributed tracing by following the OpenShift Container Platform "Installing distributed tracing" documentation.
You have installed the OpenShift CLI (oc).
You have created a project or have access to a project with the appropriate roles and permissions to create applications and other workloads in OpenShift Container Platform.

Procedure

Create an OpenTelemetryCollector custom resource (CR):

Example OpenTelemetryCollector CR

apiVersion: opentelemetry.io/v1alpha1
kind: OpenTelemetryCollector
metadata:
  name: cluster-collector
  namespace: <namespace>
spec:
  mode: deployment
  config: |
    receivers:
      zipkin:
    processors:
    exporters:
      jaeger:
        endpoint: jaeger-all-in-one-inmemory-collector-headless.tracing-system.svc:14250
        tls:
          ca_file: "/var/run/secrets/kubernetes.io/serviceaccount/service-ca.crt"
      logging:
    service:
      pipelines:
        traces:
          receivers: [zipkin]
          processors: []
          exporters: [jaeger, logging]

Verify that you have two pods running in the namespace where Red Hat OpenShift distributed tracing is installed:

$ oc get pods -n <namespace>

Example output

NAME                                          READY   STATUS    RESTARTS   AGE
cluster-collector-collector-85c766b5c-b5g99   1/1     Running   0          5m56s
jaeger-all-in-one-inmemory-ccbc9df4b-ndkl5    2/2     Running   0          15m

Verify that the following headless services have been created:

$ oc get svc -n <namespace> | grep headless

Example output

cluster-collector-collector-headless            ClusterIP   None             <none>        9411/TCP                                 7m28s
jaeger-all-in-one-inmemory-collector-headless   ClusterIP   None             <none>        9411/TCP,14250/TCP,14267/TCP,14268/TCP   16m

These services are used to configure Jaeger, Knative Serving, and Knative Eventing. The name of the Jaeger service may vary.

Install the OpenShift Serverless Operator by following the "Installing the OpenShift Serverless Operator" documentation.

Install Knative Serving by creating the following KnativeServing CR:

Example KnativeServing CR

apiVersion: operator.knative.dev/v1beta1
kind: KnativeServing
metadata:
    name: knative-serving
    namespace: knative-serving
spec:
  config:
    tracing:
      backend: "zipkin"
      zipkin-endpoint: "http://cluster-collector-collector-headless.tracing-system.svc:9411/api/v2/spans"
      debug: "false"
      sample-rate: "0.1" (1)

1	The `sample-rate` defines sampling probability. Using `sample-rate: "0.1"` means that 1 in 10 traces are sampled.

Install Knative Eventing by creating the following KnativeEventing CR:

Example KnativeEventing CR

apiVersion: operator.knative.dev/v1beta1
kind: KnativeEventing
metadata:
    name: knative-eventing
    namespace: knative-eventing
spec:
  config:
    tracing:
      backend: "zipkin"
      zipkin-endpoint: "http://cluster-collector-collector-headless.tracing-system.svc:9411/api/v2/spans"
      debug: "false"
      sample-rate: "0.1" (1)

1	The `sample-rate` defines sampling probability. Using `sample-rate: "0.1"` means that 1 in 10 traces are sampled.

Create a Knative service:

Example service

apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: helloworld-go
spec:
  template:
    metadata:
      labels:
        app: helloworld-go
      annotations:
        autoscaling.knative.dev/minScale: "1"
        autoscaling.knative.dev/target: "1"
    spec:
      containers:
      - image: quay.io/openshift-knative/helloworld:v1.2
        imagePullPolicy: Always
        resources:
          requests:
            cpu: "200m"
        env:
        - name: TARGET
          value: "Go Sample v1"

Make some requests to the service:
Example HTTPS request
```
$ curl https://helloworld-go.example.com
```
Get the URL for the Jaeger web console:
Example command
```
$ oc get route jaeger-all-in-one-inmemory  -o jsonpath='{.spec.host}' -n <namespace>
```
You can now examine traces by using the Jaeger console.