kubernetes-the-hard-way/docs/13-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.

Create a generic secret:

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:

gcloud compute ssh controller-0 \
  --command 'sudo ETCDCTL_API=3 etcdctl get \
    --cacert=/etc/etcd/ca.pem \
    --cert=/etc/etcd/kubernetes.pem \
    --endpoints=https://127.0.0.1:2379 \
    --key=/etc/etcd/kubernetes-key.pem\
    /registry/secrets/default/kubernetes-the-hard-way \
    | hexdump -C'

output

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 97 d1 2c cd 89 0d 08  |:v1:key1:..,....|
00000050  29 3c 7d 19 41 cb ea d7  3d 50 45 88 82 a3 1f 11  |)<}.A...=PE.....|
00000060  26 cb 43 2e c8 cf 73 7d  34 7e b1 7f 9f 71 d2 51  |&.C...s}4~...q.Q|
00000070  45 05 16 e9 07 d4 62 af  f8 2e 6d 4a cf c8 e8 75  |E.....b...mJ...u|
00000080  6b 75 1e b7 64 db 7d 7f  fd f3 96 62 e2 a7 ce 22  |ku..d.}....b..."|
00000090  2b 2a 82 01 c3 f5 83 ae  12 8b d5 1d 2e e6 a9 90  |+*..............|
000000a0  bd f0 23 6c 0c 55 e2 52  18 78 fe bf 6d 76 ea 98  |..#l.U.R.x..mv..|
000000b0  fc 2c 17 36 e3 40 87 15  25 13 be d6 04 88 68 5b  |.,.6.@..%.....h[|
000000c0  a4 16 81 f6 8e 3b 10 46  cb 2c ba 21 35 0c 5b 49  |.....;.F.,.!5.[I|
000000d0  e5 27 20 4c b3 8e 6b d0  91 c2 28 f1 cc fa 6a 1b  |.' L..k...(...j.|
000000e0  31 19 74 e7 a5 66 6a 99  1c 84 c7 e0 b0 fc 32 86  |1.t..fj.......2.|
000000f0  f3 29 5a a4 1c d5 a4 e3  63 26 90 95 1e 27 d0 14  |.)Z.....c&...'..|
00000100  94 f0 ac 1a cd 0d b9 4b  ae 32 02 a0 f8 b7 3f 0b  |.......K.2....?.|
00000110  6f ad 1f 4d 15 8a d6 68  95 63 cf 7d 04 9a 52 71  |o..M...h.c.}..Rq|
00000120  75 ff 87 6b c5 42 e1 72  27 b5 e9 1a fe e8 c0 3f  |u..k.B.r'......?|
00000130  d9 04 5e eb 5d 43 0d 90  ce fa 04 a8 4a b0 aa 01  |..^.]C......J...|
00000140  cf 6d 5b 80 70 5b 99 3c  d6 5c c0 dc d1 f5 52 4a  |.m[.p[.<.\....RJ|
00000150  2c 2d 28 5a 63 57 8e 4f  df 0a                    |,-(ZcW.O..|
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.

Create a deployment for the nginx web server:

kubectl create deployment nginx --image nginx

List the pod created by the nginx deployment:

kubectl get pods --selector app=nginx

output

NAME                    READY   STATUS    RESTARTS   AGE
nginx-f89759699-kpn5m   1/1     Running   0          10s

Port Forwarding

In this section you will verify the ability to access applications remotely using port forwarding.

Retrieve the full name of the nginx pod:

POD_NAME="$(kubectl get pods --selector app=nginx --output jsonpath='{.items[0].metadata.name}')"

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

kubectl port-forward "${POD_NAME}" 8080:80

output

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:

curl --head http://127.0.0.1:8080

output

HTTP/1.1 200 OK
Server: nginx/1.25.1
Date: Mon, 31 Jul 2023 11:17:53 GMT
Content-Type: text/html
Content-Length: 615
Last-Modified: Tue, 13 Jun 2023 15:08:10 GMT
Connection: keep-alive
ETag: "6488865a-267"
Accept-Ranges: bytes

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

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.

Print the nginx pod logs:

kubectl logs "${POD_NAME}"

output

...
127.0.0.1 - - [31/Jul/2023:11:15:02 +0000] "HEAD / HTTP/1.1" 200 0 "-" "curl/8.0.1" "-"

Exec

In this section you will verify the ability to execute commands in a container.

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

kubectl exec --stdin --tty $POD_"${POD_NAME}" -- nginx -v

output

nginx version: nginx/1.25.1

Services

In this section you will verify the ability to expose applications using a Service.

Expose the nginx deployment using a NodePort service:

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. Setting up cloud provider integration is out of scope for this tutorial.

Retrieve the node port assigned to the nginx service:

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

Create a firewall rule that allows remote access to the nginx node port:

gcloud compute firewall-rules create kubernetes-the-hard-way-allow-nginx-service \
  --allow "tcp:${NODE_PORT}" \
  --network kubernetes-the-hard-way

Retrieve the external IP address of a worker instance:

EXTERNAL_IP="$(gcloud compute instances describe worker-0 \
  --format 'value(networkInterfaces[0].accessConfigs[0].natIP)')"

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

curl --head "http://${EXTERNAL_IP}:${NODE_PORT}"

output

HTTP/1.1 200 OK
Server: nginx/1.25.1
Date: Mon, 31 Jul 2023 11:24:03 GMT
Content-Type: text/html
Content-Length: 615
Last-Modified: Tue, 13 Jun 2023 15:08:10 GMT
Connection: keep-alive
ETag: "6488865a-267"
Accept-Ranges: bytes

Next: Cleaning Up