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container.training/slides/k8s/prometheus-stack.md
Jérôme Petazzoni aa815a53fc 🔧 Tweak Grafana chapter
2025-11-17 17:05:46 +01:00

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# 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