DO280 - ch03s04

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Guided Exercise: Define and Apply Permissions with RBAC

Define role-based access controls and apply permissions to users.

Outcomes

Remove project creation privileges from users who are not OpenShift cluster administrators.
Create OpenShift groups and add members to these groups.
Create a project and assign project administration privileges to the project.
As a project administrator, assign read and write privileges to different groups of users.

As the student user on the workstation machine, use the lab command to prepare your system for this exercise.

This command ensures that the cluster API is reachable and creates some HTPasswd users for the exercise.

[student@workstation ~]$ lab start auth-rbac

Instructions

[student@workstation ~]$ oc login -u admin -p redhatocp \
  https://api.ocp4.example.com:6443
Login successful.

...output omitted...

List all cluster role bindings that reference the self-provisioner cluster role.

[student@workstation ~]$ oc get clusterrolebinding -o wide | \
  grep -E 'ROLE|self-provisioner'
NAME              ROLE                         ... GROUPS                     ...
self-provisioners ClusterRole/self-provisioner ... system:authenticated:oauth

Remove the privilege to create projects from all users who are not cluster administrators by deleting the self-provisioner cluster role from the system:authenticated:oauth virtual group.

Confirm that the self-provisioners cluster role binding that you found in the previous step assigns the self-provisioner cluster role to the system:authenticated:oauth group.

[student@workstation ~]$ oc describe clusterrolebindings self-provisioners
Name:         self-provisioners
Labels:       <none>
Annotations:  rbac.authorization.kubernetes.io/autoupdate: true
Role:
  Kind:  ClusterRole
  Name:  self-provisioner
Subjects:
  Kind   Name                        Namespace
  ----   ----                        ---------
  Group  system:authenticated:oauth

Remove the self-provisioner cluster role from the system:authenticated:oauth virtual group, which deletes the self-provisioners role binding.

[student@workstation ~]$ oc adm policy remove-cluster-role-from-group \
  self-provisioner system:authenticated:oauth
Warning: Your changes may get lost whenever a master is restarted, unless you prevent reconciliation of this rolebinding using the following command:
oc annotate clusterrolebinding.rbac self-provisioners 'rbac.authorization.kubernetes.io/autoupdate=false' --overwrite
clusterrole.rbac.authorization.k8s.io/self-provisioner removed: "system:authenticated:oauth"

Note

You can safely ignore the warning about your changes being lost.

Verify that the role is removed from the group. The cluster role binding self-provisioners should not exist.

[student@workstation ~]$ oc describe clusterrolebindings self-provisioners
Error from server (NotFound): clusterrolebindings.rbac.authorization.k8s.io "self-provisioners" not found

Determine whether any other cluster role bindings reference the self-provisioner cluster role.

[student@workstation ~]$ oc get clusterrolebinding -o wide | \
  grep -E 'ROLE|self-provisioner'
NAME      ROLE      AGE      USERS      GROUPS      SERVICEACCOUNTS

[student@workstation ~]$ oc login -u leader -p redhat
Login successful.

...output omitted...

Try to create a project. The operation should fail.

[student@workstation ~]$ oc new-project test
Error from server (Forbidden): You may not request a new project via this API.

Create a project and add project administration privileges to the leader user.

[student@workstation ~]$ oc login -u admin -p redhatocp
Login successful.

...output omitted...

Create the auth-rbac project.

[student@workstation ~]$ oc new-project auth-rbac
Now using project "auth-rbac" on server "https://api.ocp4.example.com:6443".

...output omitted...

Grant project administration privileges to the leader user on the auth-rbac project.

[student@workstation ~]$ oc policy add-role-to-user admin leader
clusterrole.rbac.authorization.k8s.io/admin added: "leader"

Create the dev-group and qa-group groups and add their respective members.

Create a group named dev-group.

[student@workstation ~]$ oc adm groups new dev-group
group.user.openshift.io/dev-group created

Add the developer user to the group that you created in the previous step.

[student@workstation ~]$ oc adm groups add-users dev-group developer
group.user.openshift.io/dev-group added: "developer"

Create a second group named qa-group.

[student@workstation ~]$ oc adm groups new qa-group
group.user.openshift.io/qa-group created

Add the qa-engineer user to the group that you created in the previous step.

[student@workstation ~]$ oc adm groups add-users qa-group qa-engineer
group.user.openshift.io/qa-group added: "qa-engineer"

Review all existing OpenShift groups to verify that they have the correct members.

[student@workstation ~]$ oc get groups
NAME                USERS
Default SMB Group
admins              admin
dev-group           developer
developer
editors
ocpadmins           admin
ocpdevs             developer
qa-group            qa-engineer

Note

The lab environment already contains groups from the lab LDAP directory.

As the leader user, assign write privileges for dev-group and read privileges for qa-group to the auth-rbac project.

[student@workstation ~]$ oc login -u leader -p redhat
Login successful.

...output omitted...

Using project "auth-rbac".

Add write privileges to the dev-group group on the auth-rbac project.

[student@workstation ~]$ oc policy add-role-to-group edit dev-group
clusterrole.rbac.authorization.k8s.io/edit added: "dev-group"

Add read privileges to the qa-group group on the auth-rbac project.

[student@workstation ~]$ oc policy add-role-to-group view qa-group
clusterrole.rbac.authorization.k8s.io/view added: "qa-group"

Review all role bindings on the auth-rbac project to verify that they assign roles to the correct groups and users. The following output omits default role bindings that OpenShift assigns to service accounts.

[student@workstation ~]$ oc get rolebindings -o wide | grep -v '^system:'
NAME      ROLE                AGE    USERS    GROUPS      SERVICEACCOUNTS
admin     ClusterRole/admin   60s    admin
admin-0   ClusterRole/admin   45s    leader
edit      ClusterRole/edit    30s             dev-group
view      ClusterRole/view    15s             qa-group

As the developer user, deploy an Apache HTTP Server to prove that the developer user has write privileges in the project. Also try to grant write privileges to the qa-engineer user to prove that the developer user has no project administration privileges.

[student@workstation ~]$ oc login -u developer -p developer
Login successful.

...output omitted...

Using project "auth-rbac".

Deploy an Apache HTTP Server by using the standard image stream from OpenShift.
```
[student@workstation ~]$ oc new-app --name httpd httpd:2.4
...output omitted...
--> Creating resources ...
    deployment.apps "httpd" created
    service "httpd" created
--> Success
...output omitted...
```
Note
It is safe to ignore pod security warnings for exercises in this course. OpenShift uses the Security Context Constraints controller to provide safe defaults for pod security.

Try to grant write privileges to the qa-engineer user. The operation should fail.

[student@workstation ~]$ oc policy add-role-to-user edit qa-engineer
Error from server (Forbidden): rolebindings.rbac.authorization.k8s.io is forbidden: User "developer" cannot list resource "rolebindings" in API group "rbac.authorization.k8s.io" in the namespace "auth-rbac"

Verify that the qa-engineer user can view objects in the auth-rbac project, but not modify anything.

[student@workstation ~]$ oc login -u qa-engineer -p redhat
Login successful.

...output omitted...

Using project "auth-rbac".

Attempt to scale the httpd application. The operation should fail.

[student@workstation ~]$ oc scale deployment httpd --replicas 3
Error from server (Forbidden): deployments.apps "httpd" is forbidden: User "qa-engineer" cannot patch resource "deployments/scale" in API group "apps" in the namespace "auth-rbac"

Restore project creation privileges to all users.

[student@workstation ~]$ oc login -u admin -p redhatocp
Login successful.

...output omitted...

Restore project creation privileges for all users by re-creating the self-provisioners cluster role binding that the OpenShift installer created.

[student@workstation ~]$ oc adm policy add-cluster-role-to-group \
  --rolebinding-name self-provisioners \
  self-provisioner system:authenticated:oauth
Warning: Group 'system:authenticated:oauth' not found
clusterrole.rbac.authorization.k8s.io/self-provisioner added: "system:authenticated:oauth"

Note

You can safely ignore the warning that the group was not found.

Finish

On the workstation machine, use the lab command to complete this exercise. This step is important to ensure that resources from previous exercises do not impact upcoming exercises.

[student@workstation ~]$ lab finish auth-rbac

Discuss Red Hat OpenShift Administration II: Configuring a Production Cluster

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Red Hat OpenShift Administration II: Operating a Production Kubernetes Cluster (DO280)

Haley_Ruccio

26 lip 2023

Configure, manage, and troubleshoot OpenShift clusters and containerized applicationsRed Hat OpenShift Administration II: Operating a Production Kubernetes Cluster (DO280) prepares OpenShift Cluster Administrators to perform daily administration tasks on clusters that host applications provided by internal teams and external vendors, enable self-service for cluster users with different roles, and deploy applications that require special permissions such as such as CI/CD tooling, performance monitoring, and security scanners. This course focuses on configuring multi-tenancy and security features of OpenShift as well as managing OpenShift add-ons based on operators.The skills you learn in this course can be applied using all versions of OpenShift, including Red Hat OpenShift on AWS (ROSA), Azure Red Hat OpenShift, and OpenShift Container Platform.This course is based on OpenShift Container Platform 4.12.5-10 Course TopicsDeploying packaged applications using manifests, templates, kustomize, and helm.Configuring authentication and authorization for users and applications.Protecting network traffic with network policies and exposing applications with proper network access.Deploying and managing applications using resources manifests.Enabling developer self-service of application projects.Managing OpenShift cluster updates and Kubernetes operator updates.Target AudienceSystem Administrators and Platform Operators interested in the ongoing management of OpenShift clusters, applications, users, and add-ons.Site Reliability Engineers interested in the ongoing maintenance and troubleshooting of Kubernetes clusters.System and Software Architects interested in understanding the security of an OpenShift cluster.Recommended TrainingTake our free assessment to gauge whether this offering is the best fit for your skills.Prerequisite: Red Hat OpenShift I: Containers & Kubernetes (DO180 v4.12), or equivalent skills deploying and managing Kubernetes applications using the OpenShift web console and command-line interfaces.Technology considerationsThis course requires internet access to access the cloud-based classroom environment that provides an OpenShift cluster and a remote administrator’s workstation.

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About pod security standards and warnings

alexcorcoles

17 kwi 2023

(This material has been created with the inputs of instructors and other people. We are trying to get this material published as soon as possible to address some concerns with DO180 and DO280.)With the default configuration, any namespace that you create on OpenShift 4.12 has the following labels: pod-security.kubernetes.io/audit: restrictedpod-security.kubernetes.io/audit-version: v1.24pod-security.kubernetes.io/warn: restrictedpod-security.kubernetes.io/warn-version: v1.24 These labels activate auditing and warning of the restricted pod security standard. The Kubernetes documentation describes the restricted pod security standard. Pod security standards such as restricted are not directly related to security context constraints such as the restricted SCC.Kubernetes uses an admission controller to reject pods that do not comply with pod security standards. An admission controller is a Kubernetes component that inspects every Kubernetes resource before its creation, and acts before Kubernetes creates the resource. This action can include rejecting the creation of the resource, or modifying the resource.The pod security standards are policies that include properties that workloads must follow. For example, the restricted standard requires that containers set the securityContext.allowPrivilegeEscalation field to false.Pod security standards apply both to workloads, such as deployments and jobs, and to pods.When a pod is created, the admission controller inspects the container specifications and enumerates the fields that violate the pod security standard of the namespace. The admission controller inspects the pod-security labels in the namespace to decide which pod security standard to apply (restricted, baseline, or privileged), and which action to take on violations. Namespaces can audit, warn, or enforce pod security standard violations. When the pod-security.kubernetes.io/audit annotation is set to restricted, the admission controller prevents the creation of pods that violate the security standard. When the pod-security.kubernetes.io/audit and pod-security.kubernetes.io/warn annotations are defined in the project, the admission controller does not block the creation of pods, but registers audit events or warnings.The admission controller does not enforce pod security standards for workloads. If the namespace is configured to enforce a pod security standard, then you can create a violating workload. The admission controller enforces only pod security policies on pods.Cluster administrators can use pod security standards to ensure that pods and workloads in namespaces limit their privileges. By limiting privileges, cluster administrators can mitigate what malicious pods can do.The default configuration of user namespaces in OpenShift does not restrict any workload; it only notifies users when they create workloads that do not follow pod security standards that might be enforced in future OpenShift versions.Security Context ConstraintsOpenShift introduced security context constraints (SCC) before the introduction of pod security standards in Kubernetes. SCCs automatically make security modifications to pods when they are created. By default, the system:openshift:scc:restricted-v2 cluster role binding applies to all authenticated users, so regular user workloads use the restricted-v2 SCC. For example, when you execute the following command to create a workload without any security configuration, the SCC adds security configuration to the pods: [user@host ~]$ oc create deployment test --image registry.ocp4.example.com:8443/redhattraining/hello-world-nginx (You can add the --dry-run=client -o yaml options to view the deployment manifest. The deployment manifest does not contain the security properties, which are described later.)If you inspect the pods that the deployment created, the SCC makes the following changes: [user@host ~]$ oc get pod test-b8d5658b6-7bxfs -o yamlapiVersion: v1kind: Podmetadata: annotations:... output omitted... openshift.io/scc: restricted-v2 seccomp.security.alpha.kubernetes.io/pod: runtime/default...output omitted...spec: containers: - image: registry.ocp4.example.com:8443/redhattraining/hello-world-nginx imagePullPolicy: Always name: hello-world-nginx resources: {} securityContext: allowPrivilegeEscalation: false capabilities: drop: - ALL runAsNonRoot: true runAsUser: 1000690000... output omitted... securityContext: fsGroup: 1000690000 seLinuxOptions: level: s0:c26,c20 seccompProfile: type: RuntimeDefault... output omitted... These restrictions satisfy the restricted pod security policy.The result of these defaults means that when creating a workload (such as a deployment) in a namespace without any customization, the restricted pod security standard applies, but the admission controller only warns and audits. If the workload does not satisfy the pod security standard, then the admission controller allows the workload to be created, but prints a message such as the following warning: Warning: would violate PodSecurity "restricted:v1.24": allowPrivilegeEscalation != false (container "example" must set securityContext.allowPrivilegeEscalation=false), unrestricted capabilities (container "example" must set securityContext.capabilities.drop=["ALL"]), runAsNonRoot != true (pod or container "database" must set securityContext.runAsNonRoot=true), seccompProfile (pod or container "example" must set securityContext.seccompProfile.type to "RuntimeDefault" or "Localhost") However, by default Kubernetes creates the deployment pods with the restricted-v2 SCC, with the restrictions that the previous warning included. Due to the following factors, workloads generate only a warning, and the pod security standard admission controller allows their pods:The pod security standard admission controller never enforces pod security standards on workloads (only on pods).By default, namespaces do not enforce pod security standards on pods.By default, regular workloads create pods by using the restricted-v2 SCC, which satisfies the restricted pod security standard.Even if future versions of OpenShift change the default namespace configuration to enforce the restricted pod security standard, users will continue to be able to create workloads without explicitly declaring the restrictions that the pod security standard requires, because the restricted-v2 SCC will apply such restrictions automatically.You can take the following approaches to handling pod security:For most workloads, the restricted-v2 SCC limits pod privileges adequately. When creating a workload, you receive the warning, but the workload creates pods and works correctly.You can also create your workloads by providing a full specification of the security constraints to apply, without relying on the SCC to provide the configuration. By following this approach, privileges are more explicit, and you have greater control, so you can adjust more precisely the specific privileges that are granted to workloads.When the restricted-v2 SCC and the default restricted pod security standard are not adequate for your workload, because either you require further privileges, or you need further restrictions, you must use an existing SCC, or create a custom SCC, and provide explicit security specifications. You can also adjust the namespace labels to choose a different pod security standard, and decide to audit, log, or enforce the standard.

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Welcome to the Red Hat OpenShift Administration II (DO280) group in the Red Hat Learning Community!

Deanna

17 kwi 2023

We are excited to launch a space dedicated to the Red Hat Training course Red Hat OpenShift Administration II: Operating a Production Kubernetes Cluster!To gain the most value from this group - click the "Join Group" button in the upper right hand corner.We encourage group members to collaborate in this group to discuss topics, ask questions, share best practices and tips, provide course feedback, and share their accomplishments as it relates to DO280.Read more about Red Hat OpenShift Administration II here.Thanks!

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Revision: do280-4.14-08d11e1