# Amazon EKS cluster metrics
This example demonstrates how to monitor your Amazon Elastic Kubernetes Service
(Amazon EKS) cluster with the Observability Accelerator's
[EKS monitoring module](https://github.com/aws-observability/terraform-aws-observability-accelerator/tree/main/modules/eks-monitoring).
Monitoring Amazon Elastic Kubernetes Service (Amazon EKS) for metrics has two categories:
the control plane and the Amazon EKS nodes (with Kubernetes objects).
The Amazon EKS control plane consists of control plane nodes that run the Kubernetes software,
such as etcd and the Kubernetes API server. To read more on the components of an Amazon EKS cluster,
please read the [service documentation](https://docs.aws.amazon.com/eks/latest/userguide/clusters.html).
The Amazon EKS infrastructure Terraform modules focuses on metrics collection to Amazon
Managed Service for Prometheus using the [AWS Distro for OpenTelemetry Operator](https://docs.aws.amazon.com/eks/latest/userguide/opentelemetry.html) for Amazon EKS. It deploys the [node exporter](https://github.com/prometheus/node_exporter) and [kube-state-metrics](https://github.com/kubernetes/kube-state-metrics) in your cluster.
It provides default dashboards to get a comprehensible visibility on your nodes,
namespaces, pods, and kubelet operations health. Finally, you get curated Prometheus recording rules
and alerts to operate your cluster.
Additionally, you can optionally collect custom Prometheus metrics from your applications running
on your EKS cluster.
## Prerequisites
!!! note
Make sure to complete the [prerequisites section](https://aws-observability.github.io/terraform-aws-observability-accelerator/concepts/#prerequisites) before proceeding.
## Setup
#### 1. Download sources and initialize Terraform
```
git clone https://github.com/aws-observability/terraform-aws-observability-accelerator.git
cd examples/existing-cluster-with-base-and-infra
terraform init
```
#### 2. AWS Region
Specify the AWS Region where the resources will be deployed:
```bash
export TF_VAR_aws_region=xxx
```
#### 3. Amazon EKS Cluster
To run this example, you need to provide your EKS cluster name. If you don't
have a cluster ready, visit [this example](https://aws-observability.github.io/terraform-aws-observability-accelerator/helpers/new-eks-cluster/)
first to create a new one.
Specify your cluster name:
```bash
export TF_VAR_eks_cluster_id=xxx
```
#### 4. Amazon Managed Service for Prometheus workspace (optional)
By default, we create an Amazon Managed Service for Prometheus workspace for you.
However, if you have an existing workspace you want to reuse, edit and run:
```bash
export TF_VAR_managed_prometheus_workspace_id=ws-xxx
```
To create a workspace outside of Terraform's state, simply run:
```bash
aws amp create-workspace --alias observability-accelerator --query '.workspaceId' --output text
```
#### 5. Amazon Managed Grafana workspace
To run this example you need an Amazon Managed Grafana workspace. If you have
an existing workspace, create an environment variable as described below.
To create a new workspace, visit our supporting example for Grafana.
!!! note
For the URL `https://g-xyz.grafana-workspace.eu-central-1.amazonaws.com`, the workspace ID would be `g-xyz`
```bash
export TF_VAR_managed_grafana_workspace_id=g-xxx
```
#### 6. Grafana API Key
Amazon Managed Grafana provides a control plane API for generating Grafana API keys.
As a security best practice, we will provide to Terraform a short lived API key to
run the `apply` or `destroy` command.
Ensure you have necessary IAM permissions (`CreateWorkspaceApiKey, DeleteWorkspaceApiKey`)
```bash
export TF_VAR_grafana_api_key=`aws grafana create-workspace-api-key --key-name "observability-accelerator-$(date +%s)" --key-role ADMIN --seconds-to-live 1200 --workspace-id $TF_VAR_managed_grafana_workspace_id --query key --output text`
```
## Deploy
Simply run this command to deploy the example
```bash
terraform apply
```
## Visualization
#### 1. Prometheus datasource on Grafana
Make sure to open the link in the output. After a successful deployment, this will open
the Prometheus datasource configuration on Grafana.
Click `Save & test` and you should see a notification confirming that the Amazon Managed Service for Prometheus workspace is ready to be used on Grafana.
```bash
terraform output grafana_prometheus_datasource_test
```
#### 2. Grafana dashboards
Go to the Dashboards panel of your Grafana workspace. You should see a list of dashboards under the `Observability Accelerator Dashboards`
Open a specific dashboard and you should be able to view its visualization
#### 3. Amazon Managed Service for Prometheus rules and alerts
Open the Amazon Managed Service for Prometheus console and view the details of your workspace. Under the `Rules management` tab, you should find new rules deployed.
!!! note
To setup your alert receiver, with Amazon SNS, follow [this documentation](https://docs.aws.amazon.com/prometheus/latest/userguide/AMP-alertmanager-receiver.html)
## Custom metrics collection
In addition to the cluster metrics, if you are interested in collecting Prometheus
metrics from your pods, you can use setup `custom metrics collection`.
This will instruct the ADOT collector to scrape your applications metrics based
on the configuration you provide. You can also exclude some of the metrics and save costs.
Using the example, you can edit `examples/existing-cluster-with-base-and-infra/main.tf`.
In the module `module "workloads_infra" {` add the following config (make sure the values matches your use case):
```hcl
enable_custom_metrics = true
custom_metrics_config = {
# list of applications ports (example)
ports = [8000, 8080]
# list of series prefixes you want to discard from ingestion
dropped_series_prefix = ["go_gcc"]
}
```
After applying Terraform, on Grafana, you can query Prometheus for your application metrics,
create alerts and build on your own dashboards. On the explorer section of Grafana, the
following query will give you the containers exposing metrics that matched the custom metrics
collection, grouped by cluster and node.
```promql
sum(up{job="custom-metrics"}) by (container_name, cluster, nodename)
```
