Role-based Access Control

This section describes the expectations for RBAC for Rancher Monitoring.

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:

Assigning Monitoring Roles through Custom Roles

Admins may assign custom roles in the Rancher UI for admin, editing, and viewing monitoring. These “roles” are created by default when the monitoring app is installed. Additionally, these roles are also deployed to the corresponding Kubernetes roles: admin, edit, and view ClusterRoles.

Important

The UI won’t offer monitoring-admin, monitoring-edit, and monitoring-view options when users are being added to a cluster. These monitoring roles can only be assigned by manually creating a custom role that inherits from Project Owner and Project Monitoring View roles.

1. Create the custom role:

   1.1 Click ☰ > Users & Authentication > Roles.

   1.2 Select the appropriate tab, e.g., Cluster role. Then click Create Cluster Role.

   1.3 In the Name field, create a custom role such as View Monitoring, Edit Monitoring, or Admin Monitoring.

   1.4 Click Inherit From > Add Resource, then select the Kubernetes role, as applicable, from the dropdown.

   1.5 Click Create.

2. Assign the custom role to a new user:

   2.1 Click ☰ > Cluster Management > Cluster Explore > Cluster > Cluster Members > Add.

   2.2 Search for your new user name from Select Member options displayed.

   2.3 Assign the new custom role from Cluster Permissions to the new user.

   2.4 Click Create.

Result: The new user should now be able to see the monitoring tools.

Additional Monitoring ClusterRoles

Monitoring also creates additional ClusterRoles that aren’t assigned to users by default but are created within the cluster. They aren’t 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.

note

A user bound to the View Monitoring Rancher role and read-only project permissions can’t view links in the Monitoring UI. They can still access external monitoring UIs if provided links to those UIs. If you wish to grant access to users with the View Monitoring role and read-only project permissions, move the cattle-monitoring-system namespace into the project.

Assigning Roles and ClusterRoles with kubectl

Using kubectl create

One method is to use either kubectl create clusterrolebinding or kubectl create rolebinding to assign a Role or ClusterRole. This is shown in the following examples:

• Assign to a specific user:

  • clusterrolebinding
  • rolebinding

  kubectl create clusterrolebinding my-binding --clusterrole=monitoring-ui-view --user=u-l4npx

  kubectl create rolebinding my-binding --clusterrole=monitoring-ui-view --user=u-l4npx --namespace=my-namespace

• Assign to all authenticated users:

  • clusterrolebinding
  • rolebinding

  kubectl create clusterrolebinding my-binding --clusterrole=monitoring-ui-view --group=system:authenticated

  kubectl create rolebinding my-binding --clusterrole=monitoring-ui-view --group=system:authenticated --namespace=my-namespace

Using YAML Files

Another method is to define bindings in YAML files that you create. You must first configure the RoleBinding or ClusterRoleBinding with a YAML file. Then, apply the configuration changes by running the kubectl apply command.

• Roles: Below is an example YAML file to help you configure RoleBindings in Kubernetes. You’ll need to fill in the name below.

note

Names are 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. Remember 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 Rancher project roles can be applied to members of your cluster to provide access to monitoring. These Rancher roles are tied to ClusterRoles deployed by the monitoring chart:

Non-default Rancher Permissions and Corresponding Kubernetes ClusterRoles

note

A user bound to the View Monitoring Rancher role and read-only project permissions can’t view links in the Monitoring UI. They can still access external monitoring UIs if provided links to those UIs. If you wish to grant access to users with the View Monitoring role and read-only project permissions, move the cattle-monitoring-system namespace into the 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