Viewing Logs for Deployment Replicas in Multiple Clusters

D.

The command that should be used to view the logs sent to stdout for all replicas in the Deployment across all clusters is option A, "kubectl logs [PARAM]".

Explanation: Kubernetes provides a unified interface to manage containerized applications and services. It is possible to manage Kubernetes clusters and the resources deployed within them through the Kubernetes command-line interface, kubectl.

In this scenario, the application is running in multiple Google Kubernetes Engine (GKE) clusters, and it is managed by a Deployment in each cluster. A Deployment is a Kubernetes object that represents a declarative configuration for deploying and scaling a set of Pods. Each Pod in the Deployment represents a replica of the application. By default, Kubernetes captures the logs generated by the containers running within a Pod and stores them in a file on the host system.

To view the logs for a particular Pod in a Deployment, we can use the "kubectl logs" command followed by the Pod name. However, in this scenario, we need to view the logs for all replicas of the Pod across all clusters. To achieve this, we can use the following command:

cssCopy code
kubectl logs deployment/[DEPLOYMENT_NAME] --all-containers=true 

Here, [DEPLOYMENT_NAME] refers to the name of the Deployment that manages the application across all clusters. The "--all-containers=true" flag is used to display logs for all containers in each Pod. This command will output the logs for all replicas of the Pod in the Deployment across all clusters.

Option B, "gcloud logging read [PARAM]", is used to read the logs stored in Google Cloud Logging. Google Cloud Logging is a managed logging service that provides a central place to store, search, and analyze logs from applications and services running on Google Cloud Platform. This option is not relevant in this scenario as we need to view the logs for replicas across all clusters, and not just in Google Cloud Logging.

Option C, "kubectl exec ""it [PARAM] journalctl", is used to execute a command within a running container. The "journalctl" command is used to view the system logs in a systemd journal. This option is not relevant in this scenario as we need to view the logs for replicas across all clusters, and not just in a specific container.

Option D, "gcloud compute ssh [PARAM] ""-command= "sudo journalctl"", is used to SSH into a compute engine instance and execute a command. The "sudo journalctl" command is used to view the system logs in a systemd journal. This option is not relevant in this scenario as we need to view the logs for replicas across all clusters, and not just in a specific compute engine instance.