kubernetes-the-hard-way-on-lxd

This tutorial is based on Kelsey's tutorial to deploy Kubernetes 1.18.0 the hard way, but using LXC containers in a single host.

View on GitHub

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:

 lxc exec controller-0 -- sudo ETCDCTL_API=3 etcdctl get \
   --endpoints=https://127.0.0.1:2379 \
   --cacert=/etc/etcd/ca.pem \
   --cert=/etc/etcd/kubernetes.pem \
   --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 dd 3f 36 6c ce 65 9d  |:v1:key1:.?6l.e.|
00000050  b3 b1 46 1a ba ae a2 1f  e4 fa 13 0c 4b 6e 2c 3c  |..F.........Kn,<|
00000060  15 fa 88 56 84 b7 aa c0  7a ca 66 f3 de db 2b a3  |...V....z.f...+.|
00000070  88 dc b1 b1 d8 2f 16 3e  6b 4a cb ac 88 5d 23 2d  |...../.>kJ...]#-|
00000080  99 62 be 72 9f a5 01 38  15 c4 43 ac 38 5f ef 88  |.b.r...8..C.8_..|
00000090  3b 88 c1 e6 b6 06 4f ae  a8 6b c8 40 70 ac 0a d3  |;.....O..k.@p...|
000000a0  3e dc 2b b6 0f 01 b6 8b  e2 21 29 4d 32 d6 67 a6  |>.+......!)M2.g.|
000000b0  4e 6d bb 61 0d 85 22 ea  f4 d6 2d 0a af 3c 71 85  |Nm.a.."...-..<q.|
000000c0  96 27 c9 ec 90 e3 56 8c  94 a7 1c 9a 0e 00 28 11  |.'....V.......(.|
000000d0  18 28 f4 33 42 d9 57 d9  e3 e9 1c 38 e3 bc 1e c3  |.(.3B.W....8....|
000000e0  d2 47 f3 20 60 be b8 57  a7 0a                    |.G. `..W..|
000000ea

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 run nginx --image=nginx

List the pod created by the nginx deployment:

kubectl get pods -l run=nginx

output

NAME                    READY   STATUS    RESTARTS   AGE
nginx-dbddb74b8-6lxg2   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 -l run=nginx -o 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/1.15.4
Date: Sun, 30 Sep 2018 19:23:10 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 25 Sep 2018 15:04:03 GMT
Connection: keep-alive
ETag: "5baa4e63-264"
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 - - [30/Sep/2018:19:23:10 +0000] "HEAD / HTTP/1.1" 200 0 "-" "curl/7.58.0" "-"

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 -ti $POD_NAME -- nginx -v

output

nginx version: nginx/1.15.4

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}')

Retrieve the external IP address of a worker instance:

EXTERNAL_IP=$(lxc info worker-0 | grep --only-matching  '10.0.1.[0-9]*')

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

curl -I http://${EXTERNAL_IP}:${NODE_PORT}

output

HTTP/1.1 200 OK
Server: nginx/1.15.4
Date: Sun, 30 Sep 2018 19:25:40 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 25 Sep 2018 15:04:03 GMT
Connection: keep-alive
ETag: "5baa4e63-264"
Accept-Ranges: bytes

Untrusted Workloads

This section will verify the ability to run untrusted workloads using gVisor.

Create the untrusted pod:

cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: Pod
metadata:
  name: untrusted
  annotations:
    io.kubernetes.cri.untrusted-workload: "true"
spec:
  containers:
    - name: webserver
      image: gcr.io/hightowerlabs/helloworld:2.0.0
EOF

Verification

In this section you will verify the untrusted pod is running under gVisor (runsc) by inspecting the assigned worker node.

Verify the untrusted pod is running:

kubectl get pods -o wide
NAME                       READY     STATUS    RESTARTS   AGE       IP           NODE
busybox-68654f944b-djjjb   1/1       Running   0          5m        10.200.0.2   worker-0
nginx-65899c769f-xkfcn     1/1       Running   0          4m        10.200.1.2   worker-1
untrusted                  1/1       Running   0          10s       10.200.0.3   worker-0

Get the node name where the untrusted pod is running:

INSTANCE_NAME=$(kubectl get pod untrusted --output=jsonpath='{.spec.nodeName}')

SSH into the worker node:

lxc exec ${INSTANCE_NAME} -- /bin/bash

List the containers running under gVisor:

sudo runsc --root  /run/containerd/runsc/k8s.io list
I0930 19:27:13.255142   20832 x:0] ***************************
I0930 19:27:13.255326   20832 x:0] Args: [runsc --root /run/containerd/runsc/k8s.io list]
I0930 19:27:13.255386   20832 x:0] Git Revision: 50c283b9f56bb7200938d9e207355f05f79f0d17
I0930 19:27:13.255429   20832 x:0] PID: 20832
I0930 19:27:13.255472   20832 x:0] UID: 0, GID: 0
I0930 19:27:13.255591   20832 x:0] Configuration:
I0930 19:27:13.255654   20832 x:0]              RootDir: /run/containerd/runsc/k8s.io
I0930 19:27:13.255781   20832 x:0]              Platform: ptrace
I0930 19:27:13.255893   20832 x:0]              FileAccess: exclusive, overlay: false
I0930 19:27:13.256004   20832 x:0]              Network: sandbox, logging: false
I0930 19:27:13.256128   20832 x:0]              Strace: false, max size: 1024, syscalls: []
I0930 19:27:13.256238   20832 x:0] ***************************
ID                                                                 PID         STATUS      BUNDLE                                                                                                                   CREATED                OWNER
79e74d0cec52a1ff4bc2c9b0bb9662f73ea918959c08bca5bcf07ddb6cb0e1fd   20449       running     /run/containerd/io.containerd.runtime.v1.linux/k8s.io/79e74d0cec52a1ff4bc2c9b0bb9662f73ea918959c08bca5bcf07ddb6cb0e1fd   0001-01-01T00:00:00Z
af7470029008a4520b5db9fb5b358c65d64c9f748fae050afb6eaf014a59fea5   20510       running     /run/containerd/io.containerd.runtime.v1.linux/k8s.io/af7470029008a4520b5db9fb5b358c65d64c9f748fae050afb6eaf014a59fea5   0001-01-01T00:00:00Z
I0930 19:27:13.259733   20832 x:0] Exiting with status: 0

Get the ID of the untrusted pod:

POD_ID=$(sudo crictl -r unix:///var/run/containerd/containerd.sock \
  pods --name untrusted -q)

Get the ID of the webserver container running in the untrusted pod:

CONTAINER_ID=$(sudo crictl -r unix:///var/run/containerd/containerd.sock \
  ps -p ${POD_ID} -q)

Use the gVisor runsc command to display the processes running inside the webserver container:

sudo runsc --root /run/containerd/runsc/k8s.io ps ${CONTAINER_ID}

output

I0930 19:31:31.419765   21217 x:0] ***************************
I0930 19:31:31.419907   21217 x:0] Args: [runsc --root /run/containerd/runsc/k8s.io ps af7470029008a4520b5db9fb5b358c65d64c9f748fae050afb6eaf014a59fea5]
I0930 19:31:31.419959   21217 x:0] Git Revision: 50c283b9f56bb7200938d9e207355f05f79f0d17
I0930 19:31:31.420000   21217 x:0] PID: 21217
I0930 19:31:31.420041   21217 x:0] UID: 0, GID: 0
I0930 19:31:31.420081   21217 x:0] Configuration:
I0930 19:31:31.420115   21217 x:0]              RootDir: /run/containerd/runsc/k8s.io
I0930 19:31:31.420188   21217 x:0]              Platform: ptrace
I0930 19:31:31.420266   21217 x:0]              FileAccess: exclusive, overlay: false
I0930 19:31:31.420424   21217 x:0]              Network: sandbox, logging: false
I0930 19:31:31.420515   21217 x:0]              Strace: false, max size: 1024, syscalls: []
I0930 19:31:31.420676   21217 x:0] ***************************
UID       PID       PPID      C         STIME     TIME      CMD
0         1         0         0         19:26     10ms      app
I0930 19:31:31.422022   21217 x:0] Exiting with status: 0

Next: Cleaning Up