Role-based Access Control

This section describes the expectations for RBAC for Rancher Monitoring.

• Cluster Admins
• Users with Kubernetes ClusterRole-based Permissions
  • Users with Kubernetes Admin/Edit Permissions
  • Users with Kubernetes View Permissions
  • Additional Monitoring Roles
  • Additional Monitoring ClusterRoles
• Users with Rancher Based Permissions
  • Differences in 2.5.x
  • Assigning Additional Access
• Role-based Access Control for Grafana

Cluster Admins

By default, only those with the cluster-admin ClusterRole should be able to:

• Install the rancher-monitoring App onto a cluster and all other relevant configuration performed on the chart deploy
  • e.g. whether default dashboards are created, what exporters are deployed onto the cluster to collect metrics, etc.
• Create / modify / delete Prometheus deployments in the cluster via Prometheus CRs
• Create / modify / delete Alertmanager deployments in the cluster via Alertmanager CRs
• Persist new Grafana dashboards or datasources via creating ConfigMaps in the appropriate namespace
• Expose certain Prometheus metrics to the k8s Custom Metrics API for HPA via a Secret in the cattle-monitoring-system namespace

Users with Kubernetes ClusterRole-based Permissions

The rancher-monitoring chart installs the following three ClusterRoles. By default, they aggregate into the corresponding k8s ClusterRoles:

These ClusterRoles provide different levels of access to the Monitoring CRDs based on the actions that can be performed:

On a high level, the following permissions are assigned by default as a result.

Users with Kubernetes Admin/Edit Permissions

Only those with the the cluster-admin, admin or edit ClusterRole should be able to:

• Modify the scrape configuration of Prometheus deployments via ServiceMonitor and PodMonitor CRs
• Modify the alerting / recording rules of a Prometheus deployment via PrometheusRules CRs

Users with Kubernetes View Permissions

Only those with who have some Kubernetes ClusterRole should be able to:

• View the configuration of Prometheuses that are deployed within the cluster
• View the configuration of Alertmanagers that are deployed within the cluster
• View the scrape configuration of Prometheus deployments via ServiceMonitor and PodMonitor CRs
• View the alerting/recording rules of a Prometheus deployment via PrometheusRules CRs

Additional Monitoring Roles

Monitoring also creates additional Roles that are not assigned to users by default but are created within the cluster. They can be bound to a namespace by deploying a RoleBinding that references it. To define a RoleBinding with kubectl instead of through Rancher, click here.

Admins should use these roles to provide more fine-grained access to users:

Additional Monitoring ClusterRoles

Monitoring also creates additional ClusterRoles that are not assigned to users by default but are created within the cluster. They are not aggregated by default but can be bound to a namespace by deploying a RoleBinding or ClusterRoleBinding that references it. To define a RoleBinding with kubectl instead of through Rancher, click here.

Assigning Roles and ClusterRoles with kubectl

An alternative method to using Rancher to attach a Role or ClusterRole to a user or group is by defining bindings in YAML files that you create. You must first configure the RoleBinding with the YAML file, then you apply the config changes by running the kubectl apply command.

• Roles: Below is an example of a YAML file to help you configure RoleBindings in Kubernetes. You will need to fill in the name below, and name is case-sensitive.

# monitoring-config-view-role-binding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: monitoring-config-view
  namespace: cattle-monitoring-system
roleRef:
  kind: Role
  name: monitoring-config-view
  apiGroup: rbac.authorization.k8s.io
subjects:
- kind: User
  name: u-b4qkhsnliz # this can be found via `kubectl get users -A`
  apiGroup: rbac.authorization.k8s.io

• kubectl: Below is an example of a kubectl command used to apply the binding you’ve created in the YAML file. As noted, you will need to fill in your YAML filename accordingly.

  • **kubectl apply -f monitoring-config-view-role-binding.yaml

Users with Rancher Based Permissions

The relationship between the default roles deployed by Rancher (i.e. cluster-owner, cluster-member, project-owner, project-member), the default Kubernetes roles, and the roles deployed by the rancher-monitoring chart are detailed in the table below:

Default Rancher Permissions and Corresponding Kubernetes ClusterRoles

In addition to these default Roles, the following additional Rancher project roles can be applied to members of your Cluster to provide additional access to Monitoring. These Rancher Roles will be tied to ClusterRoles deployed by the Monitoring chart:

Non-default Rancher Permissions and Corresponding Kubernetes ClusterRoles

* A User bound to the View Monitoring Rancher Role only has permissions to access external Monitoring UIs if provided links to those UIs. In order to access the Monitoring Pane to get those links, the User must be a Project Member of at least one Project.

Differences in 2.5.x

Users with the project-member or project-owners roles assigned will not be given access to either Prometheus or Grafana in Rancher 2.5.x since we only create Grafana or Prometheus on a cluster-level.

In addition, while project owners will still be only able to add ServiceMonitors / PodMonitors that scrape resources within their project’s namespace by default, PrometheusRules are not scoped to a single namespace / project. Therefore, any alert rules or recording rules created by project-owners within their project namespace will be applied across the entire cluster, although they will be unable to view / edit / delete any rules that were created outside the project’s namespace.

Assigning Additional Access

If cluster-admins would like to provide additional admin/edit access to users outside of the roles offered by the rancher-monitoring chart, the following table identifies the potential impact:

Role-based Access Control for Grafana

Rancher allows any users who are authenticated by Kubernetes and have access the Grafana service deployed by the Rancher Monitoring chart to access Grafana via the Rancher Dashboard UI. By default, all users who are able to access Grafana are given the Viewer role, which allows them to view any of the default dashboards deployed by Rancher.

However, users can choose to log in to Grafana as an Admin if necessary. The default Admin username and password for the Grafana instance will be admin/prom-operator, but alternative credentials can also be supplied on deploying or upgrading the chart.

To see the Grafana UI, install rancher-monitoring. Then:

1. In the upper left corner, click ☰ > Cluster Management.
2. On the Clusters page, go to the cluster where you want to see the visualizations and click Explore.
3. In the left navigation bar, click Monitoring.
4. Click Grafana.

Cluster Compute Resources Dashboard in Grafana

Default Dashboards in Grafana