A pod is the vehicle for running containers in Kubernetes. A pod consists of:
- One or more containers
- An IP address that is unique within the cluster
- Optionally: Environment variables, storage volumes, and enterprise features (such as health checking)
Resources are shared amongst containers in the pod. Containers within a pod also share an IP address and port space, and can find each other via localhost, or interprocess communications (such as semaphores).
Pods are used any time you need a container to be run. However, they are rarely created by a user, and are instead automatically created by controllers such as jobs, replication controllers, deployments, daemon set. The following table describes the strategy each controller uses to create pods.
| Controller | Usage Strategy |
|------------|----------------|
| Deployment | For running pods as a continuous and healthy application |
| Replication Controller | Used for the same purpose as Deployments (superseded Replication Controllers) |
| Jobs | For running pods "to completion" (which are then shut down) |
| Daemon Set | Mainly for performing operations on any nodes that match given parameters |
To retrieve the status of a pod, run the following command:
```shell
kubectl get pod <name>
```
| Return Value | Description |
|--------------|-------------|
| `READY` | Describes the number of containers that are ready to recieve traffic. |
| `STATUS` | A value from the `PodPhase` enum describing the current status of the pod. Can be `Running`, `Pending`, `Succeeded`, `Failed`, and `Unknown`. |
TODO: Link to refpage for `kubectl get pod`
To get a full description of a pod, including past events, run the following command:
```shell
kubectl describe pod <name>
```
TODO: Link to refpage for `kubectl describe pod`
#### Possible status results
| Value | Description |
|------------|----------------|
| Deployment | For running pods as a continuous and healthy application |
| Replication Controller | Used for the same purpose as Deployments (superseded Replication Controllers) |
| Jobs | For running pods "to completion" (which are then shut down) |
| Daemon Set | Mainly for performing operations on any nodes that match given parameters |