kubernetes-the-hard-way/docs/12-smoke-test.md

# Smoke Test

In this lab you will complete a series of tasks to ensure your Kubernetes cluster is functioning correctly.

## Data Encryption

In this section you will verify the ability to [encrypt secret data at rest](https://kubernetes.io/docs/tasks/administer-cluster/encrypt-data/#verifying-that-data-is-encrypted).

Create a generic secret:

```bash
kubectl create secret generic kubernetes-the-hard-way \
  --from-literal="mykey=mydata"
```

Print a hexdump of the `kubernetes-the-hard-way` secret stored in etcd:

```bash
ssh root@server \
    'etcdctl get /registry/secrets/default/kubernetes-the-hard-way | hexdump -C'
```

```text
00000000  2f 72 65 67 69 73 74 72  79 2f 73 65 63 72 65 74  |/registry/secret|
00000010  73 2f 64 65 66 61 75 6c  74 2f 6b 75 62 65 72 6e  |s/default/kubern|
00000020  65 74 65 73 2d 74 68 65  2d 68 61 72 64 2d 77 61  |etes-the-hard-wa|
00000030  79 0a 6b 38 73 3a 65 6e  63 3a 61 65 73 63 62 63  |y.k8s:enc:aescbc|
00000040  3a 76 31 3a 6b 65 79 31  3a 4f 1b 80 d8 89 72 f4  |:v1:key1:O....r.|
00000050  60 8a 2c a0 76 1a e1 dc  98 d6 00 7a a4 2f f3 92  |`.,.v......z./..|
00000060  87 63 c9 22 f4 58 c8 27  b9 ff 2c 2e 1a b6 55 be  |.c.".X.'..,...U.|
00000070  d5 5c 4d 69 82 2f b7 e4  b3 b0 12 e1 58 c4 9c 77  |.\Mi./......X..w|
00000080  78 0c 1a 90 c9 c1 23 6c  73 8e 6e fd 8e 9c 3d 84  |x.....#ls.n...=.|
00000090  7d bf 69 81 ce c9 aa 38  be 3b dd 66 aa a3 33 27  |}.i....8.;.f..3'|
000000a0  df be 6d ac 1c 6d 8a 82  df b3 19 da 0f 93 94 1e  |..m..m..........|
000000b0  e0 7d 46 8d b5 14 d0 c5  97 e2 94 76 26 a8 cb 33  |.}F........v&..3|
000000c0  57 2a d0 27 a6 5a e1 76  a7 3f f0 b7 0a 7b ff 53  |W*.'.Z.v.?...{.S|
000000d0  cf c9 1a 18 5b 45 f8 b1  06 3b a9 45 02 76 23 61  |....[E...;.E.v#a|
000000e0  5e dc 86 cf 8e a4 d3 c9  5c 6a 6f e6 33 7b 5b 8f  |^.......\jo.3{[.|
000000f0  fb 8a 14 74 58 f9 49 2f  97 98 cc 5c d4 4a 10 1a  |...tX.I/...\.J..|
00000100  64 0a 79 21 68 a0 9e 7a  03 b7 19 e6 20 e4 1b ce  |d.y!h..z.... ...|
00000110  91 64 ce 90 d9 4f 86 ca  fb 45 2f d6 56 93 68 e1  |.d...O...E/.V.h.|
00000120  0b aa 8c a0 20 a6 97 fa  a1 de 07 6d 5b 4c 02 96  |.... ......m[L..|
00000130  31 70 20 83 16 f9 0a 22  5c 63 ad f1 ea 41 a7 1e  |1p ...."\c...A..|
00000140  29 1a d4 a4 e9 d7 0c 04  74 66 04 6d 73 d8 2e 3f  |).......tf.ms..?|
00000150  f0 b9 2f 77 bd 07 d7 7c  42 0a                    |../w...|B.|
0000015a
```

The etcd key should be prefixed with `k8s:enc:aescbc:v1:key1`, which indicates the `aescbc` provider was used to encrypt the data with the `key1` encryption key.

## Deployments

In this section you will verify the ability to create and manage [Deployments](https://kubernetes.io/docs/concepts/workloads/controllers/deployment/).

Create a deployment for the [nginx](https://nginx.org/en/) web server:

```bash
kubectl create deployment nginx \
  --image=nginx:latest
```

List the pod created by the `nginx` deployment:

```bash
kubectl get pods -l app=nginx
```

```bash
NAME                     READY   STATUS    RESTARTS   AGE
nginx-56fcf95486-c8dnx   1/1     Running   0          8s
```

### Port Forwarding

In this section you will verify the ability to access applications remotely using [port forwarding](https://kubernetes.io/docs/tasks/access-application-cluster/port-forward-access-application-cluster/).

Retrieve the full name of the `nginx` pod:

```bash
POD_NAME=$(kubectl get pods -l app=nginx \
  -o jsonpath="{.items[0].metadata.name}")
```

Forward port `8080` on your local machine to port `80` of the `nginx` pod:

```bash
kubectl port-forward $POD_NAME 8080:80
```

```text
Forwarding from 127.0.0.1:8080 -> 80
Forwarding from [::1]:8080 -> 80
```

In a new terminal make an HTTP request using the forwarding address:

```bash
curl --head http://127.0.0.1:8080
```

```text
HTTP/1.1 200 OK
Server: nginx/1.27.4
Date: Sun, 06 Apr 2025 17:17:12 GMT
Content-Type: text/html
Content-Length: 615
Last-Modified: Wed, 05 Feb 2025 11:06:32 GMT
Connection: keep-alive
ETag: "67a34638-267"
Accept-Ranges: bytes
```

Switch back to the previous terminal and stop the port forwarding to the `nginx` pod:

```text
Forwarding from 127.0.0.1:8080 -> 80
Forwarding from [::1]:8080 -> 80
Handling connection for 8080
^C
```

### Logs

In this section you will verify the ability to [retrieve container logs](https://kubernetes.io/docs/concepts/cluster-administration/logging/).

Print the `nginx` pod logs:

```bash
kubectl logs $POD_NAME
```

```text
...
127.0.0.1 - - [06/Apr/2025:17:17:12 +0000] "HEAD / HTTP/1.1" 200 0 "-" "curl/7.88.1" "-"
```

### Exec

In this section you will verify the ability to [execute commands in a container](https://kubernetes.io/docs/tasks/debug-application-cluster/get-shell-running-container/#running-individual-commands-in-a-container).

Print the nginx version by executing the `nginx -v` command in the `nginx` container:

```bash
kubectl exec -ti $POD_NAME -- nginx -v
```

```text
nginx version: nginx/1.27.4
```

## Services

In this section you will verify the ability to expose applications using a [Service](https://kubernetes.io/docs/concepts/services-networking/service/).

Expose the `nginx` deployment using a [NodePort](https://kubernetes.io/docs/concepts/services-networking/service/#type-nodeport) service:

```bash
kubectl expose deployment nginx \
  --port 80 --type NodePort
```

> The LoadBalancer service type can not be used because your cluster is not configured with [cloud provider integration](https://kubernetes.io/docs/getting-started-guides/scratch/#cloud-provider). Setting up cloud provider integration is out of scope for this tutorial.

Retrieve the node port assigned to the `nginx` service:

```bash
NODE_PORT=$(kubectl get svc nginx \
  --output=jsonpath='{range .spec.ports[0]}{.nodePort}')
```

Retrieve the hostname of the node running the `nginx` pod:

```bash
NODE_NAME=$(kubectl get pods \
  -l app=nginx \
  -o jsonpath="{.items[0].spec.nodeName}")
```

Make an HTTP request using the IP address and the `nginx` node port:

```bash
curl -I http://${NODE_NAME}:${NODE_PORT}
```

```text
Server: nginx/1.27.4
Date: Sun, 06 Apr 2025 17:18:36 GMT
Content-Type: text/html
Content-Length: 615
Last-Modified: Wed, 05 Feb 2025 11:06:32 GMT
Connection: keep-alive
ETag: "67a34638-267"
Accept-Ranges: bytes
```

Next: [Cleaning Up](13-cleanup.md)