DO280 - ch05s05

Bookmark this page

Lab: Expose non-HTTP/SNI Applications

Expose applications to external access without using an ingress controller.

Outcomes

Expose a non-http application to external access by using the LoadBalancer type service.
Configure a network attachment definition for an isolated network.
Make an application accessible outside the cluster on an isolated network by using an existing node network interface.

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 configures the MetalLB operator to provide a single IP address, 192.168.50.20, for the load balancer services.

[student@workstation ~]$ lab start non-http-review

Instructions

Deploy the virtual-rtsp application to a new non-http-review-rtsp project as the developer user with the developer password, and verify that the virtual-rtsp pod is running.

The application consists of the ~/DO280/labs/non-http-review/virtual-rtsp.yaml file.

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

Change to the ~/DO280/labs/non-http-review directory.

[student@workstation ~]$ cd ~/DO280/labs/non-http-review

Create a non-http-review-rtsp project.

[student@workstation non-http-review]$ oc new-project non-http-review-rtsp
Now using project "non-http-review-rtsp" on server ...
...output omitted...

Use the oc create command to create the virtual-rtsp deployment by using the virtual-rtsp.yaml file.

[student@workstation non-http-review]$ oc create -f virtual-rtsp.yaml
deployment.apps/virtual-rtsp created

List the deployments and pods. Wait for the virtual-rtsp pod to be ready. Press Ctrl+C to exit the watch command.

[student@workstation non-http-review]$ watch oc get deployments,pods
NAME                           READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/virtual-rtsp   1/1     1            1           21s

NAME                                READY   STATUS    RESTARTS   AGE
pod/virtual-rtsp-54d8d6b57d-6jsvm   1/1     Running   0          21s

Expose the virtual-rtsp deployment by using the LoadBalancer service.

Create a load balancer service for the virtual-rtsp deployment.

[student@workstation non-http-review]$ oc expose deployment/virtual-rtsp \
  --name=virtual-rtsp-loadbalancer --type=LoadBalancer
service/virtual-rtsp-loadbalancer exposed

Retrieve the external IP address of the virtual-rtsp-loadbalancer service.

[student@workstation non-http-review]$ oc get svc/virtual-rtsp-loadbalancer
NAME                       TYPE          ...  EXTERNAL-IP    PORT(S)
virtual-rtsp-loadbalancer  LoadBalancer  ...  192.168.50.20  8554:32570/TCP

The virtual-rtsp-loadbalancer has the 192.168.50.20 external IP address.

Access the virtual-rtsp application by using the URL in the media player. Run the totem rtsp://EXTERNAL-IP:8554/stream command to play the stream in the media player.
Open the URL in the media player to confirm that the video stream is working correctly.
rtsp://192.168.50.20:8554/stream
[student@workstation non-http-review]$ totem rtsp://192.168.50.20:8554/stream ...output omitted...
Close the media player window after confirming that the video stream works correctly.

Deploy the nginx deployment to a new non-http-review-nginx project as the developer user with the developer password, and verify that the nginx pod is running. The application consists of the ~/DO280/labs/non-http-review/nginx.yaml file.

Important

The exercise is using an HTTP application as a stand-in for testing connectivity to an external network.

Create a non-http-review-nginx project.

[student@workstation non-http-review]$ oc new-project non-http-review-nginx
Now using project "non-http-review-nginx" on server ...
...output omitted...

Use the oc apply command to create the nginx deployment by using the nginx.yaml file.

[student@workstation non-http-review]$ oc apply -f nginx.yaml
deployment.apps/nginx created

List the deployments and pods. Wait for the nginx pod to be ready. Press Ctrl+C to exit the watch command.

[student@workstation non-http-review]$ watch oc get deployments,pods
NAME                    READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/nginx   1/1     1            1           53s

NAME                        READY   STATUS    RESTARTS   AGE
pod/nginx-649779cbd-d6sbv   1/1     Running   0          53s

Configure a network attachment definition for the ens4 interface, so that the isolated network can be attached to a pod.
The master01 node has two Ethernet interfaces. The ens3 interface is the main network interface of the cluster. The ens4 interface is an additional network interface for exercises that require an additional network. The ens4 interface is attached to a 192.168.51.0/24 network, with the 192.168.51.10 IP address.
You can modify the ~/DO280/labs/non-http-review/network-attachment-definition.yaml file to configure a network attachment definition by using the following parameters:
Parameter Value
name custom
type host-device
device ens4
ipam.type static
ipam.addresses {"address": "192.168.51.10/24"}
Log in to your OpenShift cluster as the admin user with the redhatocp password.
[student@workstation non-http-review]$ oc login -u admin -p redhatocp \ https://api.ocp4.example.com:6443 Login successful. ...output omitted...
Edit the ~/DO280/labs/non-http-review/network-attachment-definition.yaml file. Use the custom name, the host-device type, and the ens4 device. Configure IP address management to use the static type, with the 192.168.51.10/24 address.
apiVersion: k8s.cni.cncf.io/v1 kind: NetworkAttachmentDefinition metadata: name: custom spec: config: |- { "cniVersion": "0.3.1", "name": "custom", "type": "host-device", "device": "ens4", "ipam": { "type": "static", "addresses": [ {"address": "192.168.51.10/24"} ] } }
Use the oc create command to create the network attachment definition.
[student@workstation non-http-review]$ oc create -f \ network-attachment-definition.yaml networkattachmentdefinition.k8s.cni.cncf.io/custom created

Parameter	Value
name	`custom`
type	`host-device`
device	`ens4`
`ipam.type`	static
`ipam.addresses`	`{"address": "192.168.51.10/24"}`

The nginx application does not contain any services, so the application is not accessible outside the pod network.

Assign the ens4 network interface exclusively to the nginx pod, by using the custom network attachment definition. Edit the nginx deployment to add the k8s.v1.cni.cncf.io/networks annotation with the custom value as the developer user with the developer password.

[student@workstation non-http-review]$ oc login -u developer -p developer \
  https://api.ocp4.example.com:6443
Login successful.

...output omitted...

Edit the ~/DO280/labs/non-http-review/nginx.yaml file to add the k8s.v1.cni.cncf.io/networks annotation with the custom value.

...output omitted...
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: nginx
      annotations:
        k8s.v1.cni.cncf.io/networks: custom
    spec:
      containers:
...output omitted...

Use the oc apply command to add the annotation.

[student@workstation non-http-review]$ oc apply -f nginx.yaml
deployment.apps/nginx configured

Wait for the nginx pod to be ready. Press Ctrl+C to exit the watch command.

[student@workstation non-http-review]$ watch oc get deployments,pods
NAME                    READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/nginx   1/1     1            1           34m

NAME                        READY   STATUS    RESTARTS   AGE
pod/nginx-6f45d9f89-wp2gg   1/1     Running   0          53s

Examine the k8s.v1.cni.cncf.io/networks-status annotation in the pod.

[student@workstation ~]$ oc get pod nginx-6f45d9f89-wp2gg \
  -o jsonpath='{.metadata.annotations.k8s\.v1\.cni\.cncf\.io/network-status}'
[{
    "name": "ovn-kubernetes",
    "interface": "eth0",
    "ips": [
        "10.8.0.82"
    ],
    "mac": "0a:58:0a:08:00:52",
    "default": true,
    "dns": {}
},{
    "name": "non-http-review-nginx/custom",
    "interface": "net1",
    "ips": [
        "192.168.51.10"
    ],
    "mac": "52:54:00:01:33:0a",
    "dns": {}
}]

Note

The period is the JSONPath field access operator. Normally, you use the period to access parts of the resource, such as in the .metadata.annotations JSONPath expression. To access fields that contain periods with JSONPath, you must escape the periods with a backslash (\).

Verify that you can access the nginx application from the utility machine by using the following URL:
http://isolated-network-IP-address:8080
Use the ssh command to connect to the utility machine.
[student@workstation non-http-review]$ ssh utility ...output omitted... [student@utility ~]$
Verify that the nginx application is accessible. Use the IP address on the isolated network to access the nginx application.
[student@utility ~]$ curl 'http://192.168.51.10:8080/' <html> <body> <h1>Hello, world from nginx!</h1> </body> </html>
Exit the SSH session to go back to the workstation machine.
[student@utility ~]$ exit logout Connection to utility closed. [student@workstation non-http-review]$
Verify that you cannot access the nginx application from the workstation machine, because the workstation machine cannot access the isolated network.
Verify that the nginx application is not accessible from the workstation machine.
[student@workstation non-http-review]$ curl 'http://192.168.51.10:8080/' curl: (7) Failed to connect to 192.168.51.10 port 8080: Connection timed out
Change to the student HOME directory.
[student@workstation non-http-review]$ cd [student@workstation ~]$

Evaluation

As the student user on the workstation machine, use the lab command to grade your work. Correct any reported failures and rerun the command until successful.

[student@workstation ~]$ lab grade non-http-review

Finish

As the student user 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 non-http-review

Discuss Red Hat OpenShift Administration II: Configuring a Production Cluster

Go to community

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.

476

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.

1473

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!

1334

Revision: do280-4.14-08d11e1