Deploying the OpenTelemetry Collector in Kubernetes

15 minutes

Use the Splunk Helm chart to install the OpenTelemetry Collector in K3s
Explore your cluster in the Kubernetes Navigator

1. Installation using Helm

Install the OpenTelemetry Collector using the Splunk Helm chart. First, add the Splunk Helm chart repository to Helm and update:

helm repo add splunk-otel-collector-chart https://signalfx.github.io/splunk-otel-collector-chart && helm repo update

Using ACCESS_TOKEN={REDACTED} Using REALM=eu0 “splunk-otel-collector-chart” has been added to your repositories Using ACCESS_TOKEN={REDACTED} Using REALM=eu0 Hang tight while we grab the latest from your chart repositories… …Successfully got an update from the “splunk-otel-collector-chart” chart repository Update Complete. ⎈Happy Helming!⎈

Install the OpenTelemetry Collector Helm chart with the following commands, do NOT edit this:

helm install splunk-otel-collector --version 0.111.0 \
--set="splunkObservability.realm=$REALM" \
--set="splunkObservability.accessToken=$ACCESS_TOKEN" \
--set="clusterName=$INSTANCE-k3s-cluster" \
--set="logsEngine=otel" \
--set="splunkObservability.profilingEnabled=true" \
--set="environment=$INSTANCE-workshop" \
--set="splunkPlatform.endpoint=$HEC_URL" \
--set="splunkPlatform.token=$HEC_TOKEN" \
--set="splunkPlatform.index=splunk4rookies-workshop" \
splunk-otel-collector-chart/splunk-otel-collector \
-f ~/workshop/k3s/otel-collector.yaml

Using ACCESS_TOKEN={REDACTED}
Using REALM=eu0
NAME: splunk-otel-collector
LAST DEPLOYED: Fri May  7 11:19:01 2021
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None

You can monitor the progress of the deployment by running kubectl get pods which should typically report a new pod is up and running after about 30 seconds.

Ensure the status is reported as Running before continuing.

kubectl get pods

NAME                                                          READY   STATUS    RESTARTS   AGE
splunk-otel-collector-agent-2sk6k                             0/1     Running   0          10s
splunk-otel-collector-k8s-cluster-receiver-6956d4446f-gwnd7   0/1     Running   0          10s

Ensure there are no errors by tailing the logs from the OpenTelemetry Collector pod. The output should look similar to the log output shown in the Output tab below.

Use the label set by the helm install to tail logs (You will need to press ctrl+c to exit). Or use the installed k9s terminal UI for bonus points!

kubectl logs -l app=splunk-otel-collector -f --container otel-collector

2021-03-21T16:11:10.900Z INFO service/service.go:364 Starting receivers… 2021-03-21T16:11:10.900Z INFO builder/receivers_builder.go:70 Receiver is starting… {“component_kind”: “receiver”, “component_type”: “prometheus”, “component_name”: “prometheus”} 2021-03-21T16:11:11.009Z INFO builder/receivers_builder.go:75 Receiver started. {“component_kind”: “receiver”, “component_type”: “prometheus”, “component_name”: “prometheus”} 2021-03-21T16:11:11.009Z INFO builder/receivers_builder.go:70 Receiver is starting… {“component_kind”: “receiver”, “component_type”: “k8s_cluster”, “component_name”: “k8s_cluster”} 2021-03-21T16:11:11.009Z INFO k8sclusterreceiver@v0.21.0/watcher.go:195 Configured Kubernetes MetadataExporter {“component_kind”: “receiver”, “component_type”: “k8s_cluster”, “component_name”: “k8s_cluster”, “exporter_name”: “signalfx”} 2021-03-21T16:11:11.009Z INFO builder/receivers_builder.go:75 Receiver started. {“component_kind”: “receiver”, “component_type”: “k8s_cluster”, “component_name”: “k8s_cluster”} 2021-03-21T16:11:11.009Z INFO healthcheck/handler.go:128 Health Check state change {“component_kind”: “extension”, “component_type”: “health_check”, “component_name”: “health_check”, “status”: “ready”} 2021-03-21T16:11:11.009Z INFO service/service.go:267 Everything is ready. Begin running and processing data. 2021-03-21T16:11:11.009Z INFO k8sclusterreceiver@v0.21.0/receiver.go:59 Starting shared informers and wait for initial cache sync. {“component_kind”: “receiver”, “component_type”: “k8s_cluster”, “component_name”: “k8s_cluster”} 2021-03-21T16:11:11.281Z INFO k8sclusterreceiver@v0.21.0/receiver.go:75 Completed syncing shared informer caches. {“component_kind”: “receiver”, “component_type”: “k8s_cluster”, “component_name”: “k8s_cluster”}

Deleting a failed installation

If you make an error installing the OpenTelemetry Collector you can start over by deleting the installation using:

helm delete splunk-otel-collector

2. Validate metrics in the UI

In the Splunk UI, click the » bottom left and click on Infrastructure.

Under Containers click on Kubernetes to open the Kubernetes Navigator Cluster Map to ensure metrics are being sent in.

Validate that your cluster is discovered and reported by finding your cluster (in the workshop you will see many other clusters). To find your cluster name run the following command and copy the output to your clipboard:

echo $INSTANCE-k3s-cluster

Then in the UI, click on the “Cluster: - " menu just below the Splunk Logo, paste the Cluster name you just copied into the search box, click the box to select your cluster, and finally click off the menu into white space to apply the filter.

To examine the health of your node, hover over the pale blue background of your cluster, then click on the blue magnifying glass that appears in the top left-hand corner.

This will drill down to the node level. Next, open the Metrics sidebar by clicking on the sidebar button.

Once it is open, you can use the slider on the side to explore the various charts relevant to your cluster/node: CPU, Memory, Network, Events etc.

Deploying NGINX in K3s

Deploy a NGINX ReplicaSet into your K3s cluster and confirm the discovery of your NGINX deployment.
Run a load test to create metrics and confirm them streaming into Splunk Observability Cloud!

1. Start your NGINX

Verify the number of pods running in the Splunk UI by selecting the WORKLOADS tab. This should give you an overview of the workloads on your cluster.

Note the single agent container running per node among the default Kubernetes pods. This single container will monitor all the pods and services being deployed on this node!

Now switch back to the default cluster node view by selecting the MAP tab and selecting your cluster again.

In your AWS/EC2 or Multipass shell session change into the nginx directory:

cd ~/workshop/k3s/nginx

2. Create NGINX deployment

Create the NGINX ConfigMap¹ using the nginx.conf file:

kubectl create configmap nginxconfig --from-file=nginx.conf

configmap/nginxconfig created

Then create the deployment:

kubectl create -f nginx-deployment.yaml

deployment.apps/nginx created service/nginx created

Next, we will deploy Locust² which is an open-source tool used for creating a load test against NGINX:

kubectl create -f locust-deployment.yaml

deployment.apps/nginx-loadgenerator created service/nginx-loadgenerator created

Validate the deployment has been successful and that the Locust and NGINX pods are running.

If you have the Splunk UI open you should see new Pods being started and containers being deployed.

It should only take around 20 seconds for the pods to transition into a Running state. In the Splunk UI you will have a cluster that looks like the screenshot below:

If you select the WORKLOADS tab again you will now see that there is a new ReplicaSet and a deployment added for NGINX:

Let’s validate this in your shell as well:

kubectl get pods

NAME READY STATUS RESTARTS AGE splunk-otel-collector-k8s-cluster-receiver-77784c659c-ttmpk 1/1 Running 0 9m19s splunk-otel-collector-agent-249rd 1/1 Running 0 9m19s svclb-nginx-vtnzg 1/1 Running 0 5m57s nginx-7b95fb6b6b-7sb9x 1/1 Running 0 5m57s nginx-7b95fb6b6b-lnzsq 1/1 Running 0 5m57s nginx-7b95fb6b6b-hlx27 1/1 Running 0 5m57s nginx-7b95fb6b6b-zwns9 1/1 Running 0 5m57s svclb-nginx-loadgenerator-nscx4 1/1 Running 0 2m20s nginx-loadgenerator-755c8f7ff6-x957q 1/1 Running 0 2m20s

3. Run Locust load test

Locust, an open-source load generator, is available on port 8083 of the EC2 instance’s IP address. Open a new tab in your web browser and go to http://{==EC2-IP==}:8083/, you will then be able to see the Locust running.

Set the Spawn rate to 2 and click Start Swarming.

This will start a gentle continuous load on the application.

As you can see from the above screenshot, most of the calls will report a fail, this is expected, as we have not yet deployed the application behind it, however, NGINX is reporting on your attempts and you should be able to see those metrics.

Validate you are seeing those metrics in the UI by selecting Dashboards → Built-in Dashboard Groups → NGINX → NGINX Servers. Using the Overrides filter on k8s.cluster.name:, find the name of your cluster as returned by echo $INSTANCE-k3s-cluster in the terminal.

A ConfigMap is an API object used to store non-confidential data in key-value pairs. Pods can consume ConfigMaps as environment variables, command-line arguments, or configuration files in a volume. A ConfigMap allows you to decouple environment-specific configuration from your container images so that your applications are easily portable. ↩︎
What is Locust? ↩︎