Pod is a process that runs on your Kubernetes cluster. Pod encapsulates a granular unit known as a container. A pod can contain one or multiple containers.

Kubernetes deploys one or multiple pods on a single node which can be a physical or virtual machine. Each pod has a discrete identity with an internal IP address and port space. However, the containers within a pod can share the storage and network resources.

The following table lists the pod names and the hosts on which they are deployed depending on the labels that you assign. For information on how to assign the labels, see Associating Pods to the Nodes.

The PCF configuration is composed of several microservices that run on a set of discrete pods. Microservices are deployed during the PCF deployment. PCF uses these services to enable communication between the pods. When interacting with another pod, the service identifies the pod's IP address to initiate the transaction and acts as an endpoint for the pod.

The following table describes the PCF services and the pod on which they run.

In the current release, this feature has the following limitation introduced by Kubernetes:

When removing a node using the kubectl drain command, the pods managing the inbound traffic such as pcf-rest-ep, pcf-ldapserver-ep, and diameter-ep-rx-protocol cannot be assigned to another node. The workload of these pods' cannot be scheduled to another node since the traffic is routed through persistent connections that do not support load balance. As a result, the Grafana dashboard does not display the Transaction Per Second (TPS) for these pods.

This section describes how to associate a pod to the node based on their labels.

After you have configured a cluster, you can associate pods to the nodes through labels. This association enables the pods to get deployed on the appropriate node based on the key-value pair.

Labels are required for the pods to identify the nodes where they must get deployed and to run the services. For example, when you configure the protocol-layer label with the required key-value pair, the pods get deployed on the nodes that match the key-value pair.

To associate pods to the nodes through the labels, use the following configuration:

config 
  label 
    cdl-layer   
      key key_value 
      value value 
    oam-layer   
      key key_value 
      value value 
    protocol-layer   
      key key_value 
      value value 
    service-layer   
      key key_value 
      value value 
      end 

NOTES:

• If you opt not to configure the labels, then PCF assumes the labels with the default key-value pair.

• cdl-layer – Configures the key-value pair parameters for the CDL.

• oam-layer – Configures the key-value pair parameters for the OAM layer.

• protocol-layer – Configures the key-value pair parameters for the protocol layer.

• service-layer – Configures the key-value pair parameters for the service layer.

This section describes how to view the pod details.

If the service requires additional pods, PCF creates and deploys the pods. You can view the list of pods that are participating in your deployment through the PCF Ops Center.

You can run the kubectl command from the master node to manage the Kubernetes resources.

• To view the comprehensive pod details, use the following configuration:

  kubectl get pods -n pcf pod_name -o yaml 

  The pod details are available in YAML format.

  The output of this command results in the following information:

  • The IP address of the host where the pod is deployed.

  • The service and application that is running on the pod.

  • The ID and name of the container within the pod

  • The IP address of the pod

  • The current state and phase in which the pod is.

  • The start time from which pod is in the current state.

• To view the summary of the pod details, use the following configuration:

  kp -get pods -o wide