# Prometheus and Grafana

- What if we want metrics retention, view graphs, trends?

- A very popular combo is Prometheus+Grafana:

  - Prometheus as the "metrics engine"

  - Grafana to display comprehensive dashboards

- Prometheus also has an alert-manager component to trigger alerts

  (we won't talk about that one)

---

## Installing Prometheus and Grafana

- A complete metrics stack needs at least:

  - the Prometheus server (collects metrics and stores them efficiently)

  - a collection of *exporters* (exposing metrics to Prometheus)

  - Grafana

  - a collection of Grafana dashboards (building them from scratch is tedious)

- The Helm chart `kube-prometheus-stack` combines all these elements

- ... So we're going to use it to deploy our metrics stack!

---

## Installing `kube-prometheus-stack`

- Let's install that stack *directly* from its repo

  (without doing `helm repo add` first)

- Let's use the same name for the release, the namespace...:
  ```bash
    helm upgrade --install kube-prometheus-stack kube-prometheus-stack \
      --namespace kube-prometheus-stack --create-namespace \
      --repo https://prometheus-community.github.io/helm-charts 
  ```

- This will take a minute...

- Then check what was installed:
  ```bash
  kubectl get all --namespace kube-prometheus-stack
  ```

---

## Exposing Grafana

- Let's do this only if we have an ingress controller and a domain name!

  (we can also skip this and come back to it later)

- Create an Ingress for Grafana:
  ```bash
    kubectl create ingress --namespace kube-prometheus-stack grafana \
      --rule=grafana.`cloudnative.party`/*=kube-prometheus-stack-grafana:80
  ```

  (make sure to use *your* domain name above)

- Connect to Grafana

---

## Exposing Grafana without Ingress

- What if we don't have an ingress controller?

- We can use a `NodePort` service instead

- Option 1: `kubectl edit` or `kubectl patch` the service

  (it's `kube-prometheus-stack-grafana`)

- Option 2: pass the correct value to `helm upgrade --install`

  (check the [chart values][kps-values] to find the right one!)

- We can also use `kubectl port-forward`, or a `LoadBalacner` service!

[kps-value]: https://artifacthub.io/packages/helm/prometheus-community/kube-prometheus-stack?modal=values

---

## Grafana credentials

- What could the login and password be?

- Let's look at the Secrets available in the namespace:
  ```bash
  kubectl get secrets --namespace kube-prometheus-stack
  ```

- There is a `kube-prometheus-stack-grafana` that looks promising!

- Decode the Secret:
  ```bash
    kubectl get secret --namespace kube-prometheus-stack \
      kube-prometheus-stack-grafana -o json | jq '.data | map_values(@base64d)'
  ```

- If you don't have the `jq` tool mentioned above, don't worry...

--

- The login/password is hardcoded to `admin`/`prom-operator` 😬

---

## Grafana dashboards

- Once logged in, click on the "Dashboards" icon on the left

  (it's the one that looks like four squares)

- Then click on the "Manage" entry

- Then click on "Kubernetes / Compute Resources / Cluster"

- This gives us a breakdown of resource usage by Namespace

- Feel free to explore the other dashboards!

- There won't be much data right now, but there will be more later

???

:EN:- Installing Prometheus and Grafana
:FR:- Installer Prometheus et Grafana

:T: Observing our cluster with Prometheus and Grafana

:Q: What's the relationship between Prometheus and Grafana?
:A: Prometheus collects and graphs metrics; Grafana sends alerts
:A: ✔️Prometheus collects metrics; Grafana displays them on dashboards
:A: Prometheus collects and graphs metrics; Grafana is its configuration interface
:A: Grafana collects and graphs metrics; Prometheus sends alerts