Onboard your Kubernetes Cluster

Overview

Yotascale’s Kubernetes Integration requires the installation of an agent, which is essentially a Kubernetes POD, in each of your clusters that you want onboarded onto Yotascale. This document describes how to install the agent onto your cluster. The document also lists some pre-requisites that are required by Yotascale.

The Yotascale Kubernetes agent is compatible with the following set of components:

Kubernetes 1.17.x and above
kube-state-metrics 1.5.0 or newer
CAdvisor 0.33.2 or newer

Follow the steps below for installing the agent onto each of your Kubernetes clusters.

Installing the Agent

Step 1: Download the Deployment Descriptor

Login to Yotascale and click on Manage Cloud Services from the Settings menu
Once on the Manage Connections page, click on the Add Cluster → Kubernetes Button in the List of Clusters table.

Click the Download button to save the Deployment Descriptor.

Step 2: Update the Environment Variables for your Cluster

The deployment descriptor lists multiple environment variables in the last few lines of the file. You would need to configure some of them according to your environment.

Environment Variable	Description	Value needs to be specified
KUBERNETES_CLUSTER_ID	Give your cluster a unique name in order to identify clusters within Yotascale.	Yes
PROMETHEUS_API_ENDPOINT	Point the agent to the Prometheus API by providing the URL.	Yes
YOTASCALE_API_KEY	This Environment variable authenticates (and identifies) this agent against a Service Role that your administrators have subscribed to by default. This will be pre-populated in the deployment descriptor and does not need to be updated by the user.	No
YOTASCALE_KUBERNETES_API_ENDPOINT	This is the URL of the Yotascale API that allows the agent to authenticate iteself with Yotascale, and send frequent heartbeats for monitoring. This URL will be pre-populated in the deployment descriptor.	No

Step 3 (Optional): Create Self-Signed Certificate Secret for calling Prometheus API

If your Prometheus is using a self-signed certificate, you would need to create a Secret with your PEM file and mount the Secret as a Volume and file on the Pod. The agent would use this certificate when making calls to Prometheus.

Create a Secret named ‘prometheus-certificate’ using the following command. The certificate could be named anything.

BASH

kubectl create secret generic prometheus-certificate \
 --from-file=/path/to/certificate.pem --output=yaml --namespace yotascale

When the Pod is up and running, the certificate is mounted at the following location

BASH

/opt/yotascale/prometheus-certificate/certificate.pem

The following Pod logs would show that the agent is using the self-signed certificate

CODE

Prometheus cert for Cluster my-cluster found at location /opt/yotascale/prometheus-certificate/name-of-your-cert.pem

CODE

Prometheus Certificate found at /opt/yotascale/prometheus-certificate/name-of-your-cert.pem for Cluster my-cluster. Verifying using custom cert.

Step 4 : Deploy Yotascale Agent on Kubernetes

Once you have updated the deployment descriptor, apply the updated file onto your cluster

BASH

kubectl apply -f yotascale-kubernetes-agent-deployment.yaml

Step 5: Verifying the Installation

Once you have applied the deployment descriptor to your cluster, you will see it appear in the List of Clusters widget in the Manage Connections Page.

You can also look at the logs from the agent to ensure there are no error logs.

BASH

kubectl logs -l app=yotascale-kubernetes-agent -n yotascale

Metric Ingestion from Prometheus

The Yotascale Kubernetes Agent assumes the existence of a Prometheus installation for your cluster. Furthermore, it assumes that Prometheus is scraping kube-state-metrics and cAdvisor, two common tools for capturing cluster and container level metrics.

The Yotascale agent uses the following metrics:

kube-state-metrics Metrics

The following metrics enable Yotascale to build a layout of your Kubernetes cluster, determine relationship between various Kubernetes objects and understand resource requirements.

Metric Name	Description
kube_node_info	Provides information on the nodes running in the cluster. This includes the "provider id" which contains the resource id of the AWS EC2 instance which corresponds to the kubernetes node.
kube_node_labels	Provides information about the node such as the instance type e.g c4.xlarge, the region, the availability zone, the os and the role (master/node)
kube_pod_info	Provides information on the pods running on the clusters including the name of the nodes the pods are running on
kube_pod_labels	Provides label information for pods.
kube_pod_container_info	Provides information on the containers running under each pod.
kube_pod_container_resource_requests_memory_bytes	Requested memory for the container
kube_pod_container_resource_requests_cpu_cores	Requested CPU cores for the container
kube_pod_container_resource_limits_memory_bytes	Upper limit usage for memory usage for the container
kube_pod_container_resource_limits_cpu_cores	Upper limit usage for CPU cores for the container
kube_deployment_labels	The list of deployments and their basic metadata such as namespace
kube_replicaset_owner	Name of the deployment that creates each replica set.
kube_pod_owner	Name of the replica set or daemon set that creates each pods
kube_hpa_labels	Identify the HPA. Map to namespace.
kube_hpa_spec_max_replicas	Max Replicas configured in the HPA
kube_hpa_spec_min_replicas	Min Replicas configured in the HPA

cAdvisor Metrics

The following metrics enable Yotascale determine actual resource usage for each of your containers.

Metric Name	Description
container_memory_usage_bytes	Actual memory usage by a container
container_cpu_usage_seconds_total	Actual CPU core usage by a container

Release Notes

0.1.7

docker pull yotascale/yotascale-kubernetes-agent:0.1.7

The labels "pod_name" and "container_name" have been removed from cAdvisor metrics in Kubernetes 1.16 and are now available as "pod" and "container". The agent now has support for both metric names.
Added ability to upload detailed logs to Yotascale allowing Yotascale to show logs and detailed agent status on the UI (as part of a later release of the UI)