II: Building kubernetes home lab with k3d — Monitoring

22.01.2021 - AYB - Reading time ~4 Minutes

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Part II: Kubernetes observability with Prometheus, Loki and Grafana

Set up Helm

Helm is the package manager for Kubernetes. Something like apt or brew but for Kubernetes.

Run brew install helm Linux users: follow the manual page to install for your OS

Deploy a test Nginx server using Helm

Now we’re going to deploy a single page web-server that will respond to the http://k3d.localhost requests at the root path.

First, add the Bitnami repo and update the stuff:

helm repo add bitnami https://charts.bitnami.com/bitnami
helm install my-release bitnami/nginx

we’re using bitnami because we want only nginx server without ingress controller and other stuff which is deployed by default from the official Nginx repo

Note: documentation on Bitnami Nginx chart is available here

Output:

Hang tight while we grab the latest from your chart repositories...
...Successfully got an update from the "bitnami" chart repository
Update Complete. ⎈Happy Helming!⎈

Deploying Nginx

helm install test-nginx bitnami/nginx --set clusterDomain=k3d.local --set replicaCount=2 --set metrics.enabled=true --set service.type=ClusterIP

Metrics.enabled is set to true to be used later here. Service.type was set because by default its setting is LoadBalancer but we already have Traefik here so it will make the deployment generating a lot of errors and overall inoperable.

If you’ll decide later to change any parameters, the easiest way is to uninstall the chart and deploy again: helm uninstall test-nginx. The right way is the “Rolling update”, but we’re not discussing it here yet

Create Ingress route for our Nginx

Copy the ingressroute.yml to a new file, e.g. ingressroute.nginx.yml and make it look like this:

apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: test-nginx
spec:
  entryPoints:
    - web
  routes:
  - match: Host(`k3d.local`)
    kind: Rule
    services:
    - name: test-nginx
      port: 80

Now save and apply with k apply -f ingressroute.nginx.yml

Note that we didn’t specify namespace neither in helm deployment nor ingress route deployment. So our Nginx is running at the default namespace. For the purposes of this tutorial it’s ok, but you should consider specifying namespaces for everything you’re doing in Kubernetes, because having everything in the default one will make your life tough and painful.

Point your browser now to http://k3d.local/ and you should see the “Welcome to nginx!” page.

Setting up Prometheus and Grafana

Deploying Prometheus and Grafana to our test cluster

Source

helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
helm repo update
helm install monitoring prometheus-community/kube-prometheus-stack

This may take a while since your k3d cluster is pulling all the required images and they’re quite big

Output:

NAME: monitoring
LAST DEPLOYED: Sun May 29 18:31:56 2022
NAMESPACE: default
STATUS: deployed
REVISION: 1
NOTES:
kube-prometheus-stack has been installed. Check its status by running:
  kubectl --namespace default get pods -l "release=monitoring"

Visit https://github.com/prometheus-operator/kube-prometheus for instructions on how to create & configure Alertmanager and Prometheus instances using the Operator.
kubectl --namespace default get pods -l "release=monitoring"
NAME                                                   READY   STATUS    RESTARTS   AGE
monitoring-kube-state-metrics-56bfd4f44f-nmpr8         1/1     Running   0          2m44s
monitoring-prometheus-node-exporter-vf66j              1/1     Running   0          2m44s
monitoring-prometheus-node-exporter-h8qpr              1/1     Running   0          2m44s
monitoring-prometheus-node-exporter-jzxz2              1/1     Running   0          2m44s
monitoring-kube-prometheus-operator-5dbdd57558-ztd75   1/1     Running   0          2m44s

Now lets check whats up with ports:

kgs -A -l "release=monitoring"

Output:

NAMESPACE     NAME                                                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)     AGE     SELECTOR
kube-system   monitoring-kube-prometheus-kube-controller-manager   ClusterIP   None            <none>        10257/TCP   3m43s   component=kube-controller-manager
kube-system   monitoring-kube-prometheus-kube-etcd                 ClusterIP   None            <none>        2379/TCP    3m43s   component=etcd
kube-system   monitoring-kube-prometheus-kube-proxy                ClusterIP   None            <none>        10249/TCP   3m43s   k8s-app=kube-proxy
kube-system   monitoring-kube-prometheus-coredns                   ClusterIP   None            <none>        9153/TCP    3m43s   k8s-app=kube-dns
kube-system   monitoring-kube-prometheus-kube-scheduler            ClusterIP   None            <none>        10251/TCP   3m43s   component=kube-scheduler
default       monitoring-kube-prometheus-prometheus                ClusterIP   10.43.184.203   <none>        9090/TCP    3m43s   app.kubernetes.io/name=prometheus,prometheus=monitoring-kube-prometheus-prometheus
default       monitoring-kube-prometheus-operator                  ClusterIP   10.43.153.170   <none>        443/TCP     3m43s   app=kube-prometheus-stack-operator,release=monitoring
default       monitoring-kube-prometheus-alertmanager              ClusterIP   10.43.89.13     <none>        9093/TCP    3m43s   alertmanager=monitoring-kube-prometheus-alertmanager,app.kubernetes.io/name=alertmanager
default       monitoring-prometheus-node-exporter                  ClusterIP   10.43.147.53    <none>        9100/TCP    3m43s   app=prometheus-node-exporter,release=monitoring
default       monitoring-kube-state-metrics                        ClusterIP   10.43.145.194   <none>        8080/TCP    3m43s   app.kubernetes.io/instance=monitoring,app.kubernetes.io/name=kube-state-metrics

By the way, if you have already installed Lens you should see now all the fancy metrics about your cluster in a sexy infographic form at the cluster dashboard.

Exposing Grafana to the browser

First, edit the localhost line in the /etc/hosts to be like: 127.0.0.1 localhost k3d.local grafana.k3d.local

Second, as we did before, copy ingressroute.yml to a new file (e.g. to ingressroute.grafana.yml) and make it look like that:

apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: monitoring-grafana
spec:
  entryPoints:
    - web
  routes:
  - match: Host(`grafana.k3d.local`)
    kind: Rule
    services:
    - name: monitoring-grafana
      port: 80

Now k apply -f ingressroute.grafana.yml

From this point you should be able to open Grafana interface in your browser using the http://grafana.k3d.local address.

For this stack Grafana default credentials are:

User: admin
Password: prom-operator

At the dashboards browser you can look at the various pre-installed Kubernetes Observability Dashboards.

Customizing Grafana dashboards is another topic and will not be discussed here.

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