# Lab: Kubernetes and OpenShift Command-Line Interfaces and APIs Find detailed information about your OpenShift cluster and assess its health by querying its Kubernetes resources. **Outcomes** * Use the command line to retrieve information about the cluster resources. * Identify cluster operators and API resources. * List the available namespaced resources. * Identify the resources that belong to the core API group. * List the resource types that the OpenShift configuration API group provides. * List the resource usage of containers in a pod. * Use the JSONPath filter to get the number of allocatable pods and compute resources for a node. * List the memory and CPU usage of all pods in the cluster. * Use `jq` filters to retrieve the `conditions` status of a pod. * View cluster events and alerts. As the `student` user on the `workstation` machine, use the `lab` command to prepare your system for this exercise. ```plaintext [student@workstation ~]$ lab start cli-review ``` The API URL of your OpenShift cluster is [https://api.ocp4.example.com:6443](https://api.ocp4.example.com:6443), and the `oc` command is already installed on your `workstation` machine. **Procedure 2.4. Instructions** The API URL of your OpenShift cluster is [https://api.ocp4.example.com:6443](https://api.ocp4.example.com:6443), and the `oc` command is already installed on your `workstation` machine. Log in to the OpenShift cluster as the `developer` user with the `developer` password. Use the `cli-review` project for your work. 1. Log in to the OpenShift cluster and create the `cli-review` project. 1. Log in to the OpenShift cluster. ```plaintext [student@workstation ~]$ oc login -u developer -p developer \ https://api.ocp4.example.com:6443 ...output omitted... ``` 2. Create the `cli-review` project. ```plaintext [student@workstation ~]$ oc new-project cli-review Now using project "storage-review" on server "https://api.ocp4.example.com:6443". ...output omitted... ``` [Hide Solution](https://rol.redhat.com/rol/app/#) 2. Use the `oc` command to list the following information for the cluster: * Retrieve the cluster version. * Identify the supported API versions. * Identify the fields for the `pod.spec.securityContext` object. 1. Identify the cluster version. ```plaintext [student@workstation ~]$ oc version Client Version: 4.12.0 Kustomize Version: v4.5.7 Kubernetes Version: v1.25.4+77bec7a ``` 2. Identify the supported API versions. ```plaintext [student@workstation ~]$ oc api-versions admissionregistration.k8s.io/v1 apiextensions.k8s.io/v1 apiregistration.k8s.io/v1 apiserver.openshift.io/v1 apps.openshift.io/v1 apps/v1 ...output omitted... ``` 3. Identify the fields for the `pod.spec.securityContext` object. ```plaintext [student@workstation ~]$ oc explain pod.spec.securityContext KIND: Pod VERSION: v1 RESOURCE: securityContext DESCRIPTION: ...output omitted... ``` [Hide Solution](https://rol.redhat.com/rol/app/#) 3. From the terminal, log in to the OpenShift cluster as the `admin` user with the `redhatocp` password. Then, use the command line to identify the following cluster resources: * List the cluster operators. * Identify the available namespaced resources. * Identify the resources that belong to the core API group. * List the resource types that the [`oauth.openshift.io`](http://oauth.openshift.io) API group provides. * List the events in the `openshift-image-registry` namespace. [Show Solution](https://rol.redhat.com/rol/app/#) 4. Identify the following information about the cluster services and its nodes: * Retrieve the `conditions` status of the `etcd-master01` pod in the `openshift-etcd` namespace by using `jq` filters to limit the output. * List the compute resource usage of the containers in the `etcd-master01` pod in the `openshift-etcd` namespace. * Get the number of allocatable pods for the `master01` node by using a JSONPath filter. * List the memory and CPU usage of all pods in the cluster. * Retrieve the compute resource consumption of the `master01` node. * Retrieve the capacity and allocatable CPU for the `master01` node by using a JSONPath filter. 1. Retrieve the `conditions` status of the `etcd-master01` pod in the `openshift-etcd` namespace. Use `jq` filters to limit the output to the `.status.conditions` attribute of the pod. ```plaintext [student@workstation ~]$ oc get pods etcd-master01 -n openshift-etcd \ -o json | jq .status.conditions [ { "lastProbeTime": null, "lastTransitionTime": "2023-03-12T16:40:35Z", "status": "True", "type": "Initialized" }, { "lastProbeTime": null, "lastTransitionTime": "2023-03-12T16:40:47Z", "status": "True", "type": "Ready" }, { "lastProbeTime": null, "lastTransitionTime": "2023-03-12T16:40:47Z", "status": "True", "type": "ContainersReady" }, { "lastProbeTime": null, "lastTransitionTime": "2023-03-12T16:40:23Z", "status": "True", "type": "PodScheduled" } ] ``` 2. List the resource usage of the containers in the `etcd-master01` pod in the `openshift-etcd` namespace. ```plaintext [student@workstation ~]$ oc adm top pods etcd-master01 \ -n openshift-etcd --containers POD NAME CPU(cores) MEMORY(bytes) etcd-master01 POD 0m 0Mi etcd-master01 etcd 54m 1513Mi etcd-master01 etcd-metrics 5m 24Mi etcd-master01 etcd-readyz 4m 39Mi etcd-master01 etcdctl 0m 0Mi ``` 3. Use a JSONPath filter to determine the number of allocatable pods for the `master01` node. ```plaintext [student@workstation ~]$ oc get node master01 \ -o jsonpath='{.status.allocatable.pods}{"\n"}' 250 ``` 4. List the memory and CPU usage of all pods in the cluster. Use the `--sum` option to print the sum of the resource usage. The resource usage on your system probably differs. ```plaintext [student@workstation ~]$ oc adm top pods -A --sum NAMESPACE NAME CPU(cores) MEMORY(bytes) metallb-system controller-5f6dfd8c4f-ddr8v 0m 56Mi metallb-system metallb-operator-controller-manager-6666bf5467-n2zsv 0m 50Mi metallb-system metallb-operator-webhook-server-74c46ddb74-tjjj5 0m 26Mi metallb-system speaker-2dds4 9m 210Mi nfs-client-provisioner nfs-client-provisioner-79c9d77bf5-cr8n8 0m 16Mi ...output omitted... 505m 8982Mi ``` 5. Retrieve the resource consumption of the `master01` node. ```plaintext [student@workstation ~]$ oc adm top node NAME CPU(cores) CPU% MEMORY(bytes) MEMORY% master01 1199m 15% 12555Mi 66% ``` 6. Use a JSONPath filter to determine the capacity and allocatable CPU for the `master01` node. ```plaintext [student@workstation ~]$ oc get node master01 -o jsonpath=\ 'Allocatable: {.status.allocatable.cpu}{"\n"}'\ 'Capacity: {.status.capacity.cpu}{"\n"}' Allocatable: 7500m Capacity: 8 ``` [Hide Solution](https://rol.redhat.com/rol/app/#) 5. Retrieve debugging information for the cluster. Specify the `/home/student/DO180/labs/cli-review/debugging` directory as the destination directory. Then, generate debugging information for the `kube-apiserver` cluster operator. Specify the `/home/student/DO180/labs/cli-review/inspect` directory as the destination directory. Limit the debugging information to the last five minutes. 1. Retrieve debugging information for the cluster. Save the output to the `/home/student/DO180/labs/cli-review/debugging` directory. ```plaintext [student@workstation ~]$ oc adm must-gather \ --dest-dir /home/student/DO180/labs/cli-review/debugging [must-gather ] OUT Using must-gather plug-in image: quay.io/openshift-release-dev/ocp-v4.0-art-dev@sha256:07d3...e94c ...output omitted... Reprinting Cluster State: When opening a support case, bugzilla, or issue please include the following summary data along with any other requested information: ClusterID: 94ff22c1-88a0-44cf-90f6-0b7b8b545434 ClusterVersion: Stable at "4.12.0" ClusterOperators: All healthy and stable ``` 2. Generate debugging information for the `kube-apiserver` cluster operator. Save the output to the `/home/student/DO180/labs/cli-review/inspect` directory, and limit the debugging information to the last five minutes. ```plaintext [student@workstation ~]$ oc adm inspect clusteroperator kube-apiserver \ --dest-dir /home/student/DO180/labs/cli-review/inspect --since 5m Gathering data for ns/openshift-config... Gathering data for ns/openshift-config-managed... Gathering data for ns/openshift-kube-apiserver-operator... Gathering data for ns/openshift-kube-apiserver... Gathering data for ns/metallb-system... Gathering data for ns/openshift-monitoring... Gathering data for ns/openshift-machine-api... Gathering data for ns/openshift-multus... Gathering data for ns/openshift-cluster-node-tuning-operator... Gathering data for ns/openshift-cluster-storage-operator... Wrote inspect data to /home/student/DO180/labs/cli-review/inspect. ``` [Hide Solution](https://rol.redhat.com/rol/app/#) **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. ```plaintext [student@workstation ~]$ lab grade cli-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. ```plaintext [student@workstation ~]$ lab finish cli-review ```