# Assignment

The Nautilus DevOps team is diving into Kubernetes for application management. One team member has a task to create a pod according to the details below:


Create a pod named pod-httpd using the httpd image with the latest tag. Ensure to specify the tag as httpd:latest.

Set the app label to httpd_app, and name the container as httpd-container.

Note: The kubectl utility on the jump-host has been configured to work with the Kubernetes cluster.

# Solution

# Kubernetes Pod — `pod-httpd`

A single pod running the `httpd:latest` image, with an `app: httpd_app` label and a
named container. Applied inline via a heredoc — no manifest file on disk.

## Apply (heredoc → kubectl)

```bash
kubectl apply -f - <<'EOF'
apiVersion: v1
kind: Pod
metadata:
  name: pod-httpd
  labels:
    app: httpd_app
spec:
  containers:
    - name: httpd-container
      image: httpd:latest
EOF
```

## How it works

### The heredoc apply pattern

- **`kubectl apply -f -`** — the `-f -` tells kubectl to read the manifest from
  **stdin** instead of a file. The heredoc feeds the YAML straight in, so nothing is
  written to disk.
- **`<<'EOF'` (delimiter quoted)** — quoting `EOF` disables shell expansion inside the
  body, so any `$VAR`, backticks, or `$(...)` in a manifest stay literal rather than
  being interpreted by the shell. For Kubernetes YAML this is almost always what you
  want. Use unquoted `<<EOF` only when you deliberately want the shell to interpolate a
  variable into the manifest before it reaches kubectl.
- **Indentation still matters** — YAML inside the heredoc must keep exact indentation,
  spaces not tabs.

### The manifest, field by field

- **`apiVersion: v1` / `kind: Pod`** — a Pod is a core (`v1`) object, the smallest
  deployable unit in Kubernetes: one or more containers sharing a network namespace and
  storage.
- **`metadata.name: pod-httpd`** — the pod's name, exactly as required.
- **`metadata.labels.app: httpd_app`** — the required label. Labels are key/value tags
  used by selectors (Services, ReplicaSets, `kubectl get -l`) to target the pod, so
  `kubectl get pods -l app=httpd_app` will match this pod.
- **`spec.containers`** — the list of containers in the pod, here a single entry:
  - **`name: httpd-container`** — the container name, exactly as required. This is the
    name you'd pass to `kubectl logs` / `kubectl exec -c`.
  - **`image: httpd:latest`** — the Apache HTTP Server image at the `latest` tag,
    specified explicitly as required. Writing just `httpd` would default the tag to
    `latest` anyway, but the task asks for the tag to be stated, so it's spelled out.

### Label vs. name — two different things

Easy to conflate, but distinct:
- the **pod name** (`pod-httpd`) uniquely identifies the pod in its namespace, and
- the **`app` label** (`httpd_app`) is a selector tag that can be shared across many
  pods.

They live in different manifest fields (`metadata.name` vs `metadata.labels`) and serve
different purposes.

## Verify

```bash
# Pod is running with the correct name
kubectl get pod pod-httpd -o wide

# Label is set
kubectl get pod pod-httpd --show-labels

# Container name and image are correct
kubectl get pod pod-httpd \
  -o jsonpath='{.spec.containers[0].name}{"  "}{.spec.containers[0].image}{"\n"}'
```

Expected — `pod-httpd` in `Running` status, labels showing `app=httpd_app`, and the
jsonpath printing `httpd-container  httpd:latest`.

> If the pod sits in `ImagePullBackOff`, the node may be offline or rate-limited on the
> pull. `kubectl describe pod pod-httpd` shows the pull events under `Events:`.