Accessing cluster services

MetalK8s GUI

This GUI is deployed during the Bootstrap installation, and can be used for operating, extending and upgrading a MetalK8s cluster.

Gather required information

  1. Get the workload plane IP of the bootstrap node.

    root@bootstrap $ salt-call grains.get metalk8s:workload_plane_ip
local:
    <the workload plane IP>

  2. Retrieve the active NodePort number for the UI (here 30923):

    root@boostrap $ kubectl --kubeconfig=/etc/kubernetes/admin.conf get svc metalk8s-ui -n metalk8s-ui

NAME                  TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
metalk8s-ui           NodePort    10.104.61.208   <none>        80:30923/TCP     3h

Use MetalK8s UI

Once you have gathered the IP address and the port number, open your web browser and navigate to the URL http://<ip>:<port>, replacing placeholders with the values retrieved before.

The login page is loaded, and should resemble the following:

../_images/login.png

In the bottom left corner of the page, click the link Accept SSL Certificate for Kubernetes. In the new tab, click the button Advanced..., then select Accept the risk and continue.

Follow the same steps for the second link, Accept SSL Certificate for Salt.

Go back to the first tab, then log in with the default login / password (admin / admin).

The landing page should look like this:

../_images/monitoring.png

This page displays two monitoring indicators:

  1. the Cluster Status, which evaluates if control-plane services are all up and running

  2. the list of alerts stored in Alertmanager

Grafana

You will first need the latest kubectl version installed on your host.

From the bootstrap node, get the port used by Grafana:

root@bootstrap $ kubectl --kubeconfig=/etc/kubernetes/admin.conf get service grafana -n metalk8s-monitoring

NAME      TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)    AGE
grafana   ClusterIP   10.109.125.193   <none>        3000/TCP   1h

Please note the port used by Grafana (here 3000)

To authenticate with the cluster, retrieve the admin kubeconfig on your host:

user@your-host $ scp root@bootstrap:/etc/kubernetes/admin.conf ./admin.conf

Forward the port used by Grafana:

user@your-host $ kubectl --namespace metalk8s-monitoring port-forward svc/grafana 3000

Then open your web browser and navigate to http://localhost:3000

Salt

MetalK8s uses SaltStack to manage the cluster. The Salt Master runs in a Pod on the Bootstrap node.

The Pod name is salt-master-<bootstrap hostname>, and it contains two containers: salt-master and salt-api.

To interact with the Salt Master with the usual CLIs, open a terminal in the salt-master container (we assume the Bootstrap hostname to be bootstrap):

root@bootstrap $ kubectl exec -it -n kube-system -c salt-master --kubeconfig /etc/kubernetes/admin.conf salt-master-bootstrap bash

Todo

  • how to access / use SaltAPI

  • how to get logs from these containers