The provided YAML manifest defines a Kubernetes Deployment object that creates and manages a set of pods running the NGINX web server. Let’s analyze each statement in detail:
A. The created pods are receiving traffic on port 80.
Correct:
The containerPort: 80 field in the manifest specifies that the NGINX container listens on port 80 for incoming traffic.
While this does not expose the pods externally, it ensures that the application inside the pod (NGINX) is configured to receive traffic on port 80.
B. This manifest is used to create a deployment.
Correct:
The kind: Deployment field explicitly indicates that this manifest is used to create a Kubernetes Deployment .
Deployments are used to manage the desired state of pods, including scaling, rolling updates, and self-healing.
C. This manifest is used to create a deploymentConfig.
Incorrect:
deploymentConfig is a concept specific to OpenShift, not standard Kubernetes. In OpenShift, deploymentConfig provides additional features like triggers and lifecycle hooks, but this manifest uses the standard Kubernetes Deployment object.
D. Four pods are created as a result of applying this manifest.
Why These Statements?
Traffic on Port 80:
The containerPort: 80 field ensures that the NGINX application inside the pod listens on port 80. This is critical for the application to function as a web server.
Deployment Object:
The kind: Deployment field confirms that this manifest creates a Kubernetes Deployment, which manages the lifecycle of the pods.
Replica Count:
The replicas: 3 field explicitly states that three pods will be created. Any assumption of four pods is incorrect.
Additional Context:
Kubernetes Deployments:Deployments are one of the most common Kubernetes objects used to manage stateless applications. They ensure that the desired number of pod replicas is always running and can handle updates or rollbacks seamlessly.
Ports in Kubernetes:The containerPort field in the pod specification defines the port on which thecontainerized application listens. However, to expose the pods externally, a Kubernetes Service (e.g., NodePort, LoadBalancer) must be created.
JNCIA Cloud References:
The JNCIA-Cloud certification covers Kubernetes concepts, including Deployments, Pods, and networking. Understanding how Deployments work and how ports are configured is essential for managing containerized applications in cloud environments.
For example, Juniper Contrail integrates with Kubernetes to provide advanced networking and security features for Deployments like the one described in the exhibit.
[Reference:, Kubernetes Documentation: Deployments, Kubernetes Documentation: Pod Networking, Juniper JNCIA-Cloud Study Guide: Kubernetes Architecture, ]
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