The Hard Way

Inicializando os Workers (Nós)

Vamos iniciar três nós worker do Kubernetes. Os seguintes componentes serão instalados em cada nó: runc, gVisor, plug-ins de rede de contêiner, containerd, kubelet e kube-proxy.

Pre Requisitos

for instance in worker-0 worker-1 worker-2; do
  external_ip=$(aws ec2 describe-instances --filters \
    "Name=tag:Name,Values=${instance}" \
    "Name=instance-state-name,Values=running" \
    --output text --query 'Reservations[].Instances[].PublicIpAddress')

  echo ssh -i kubernetes.id_rsa ubuntu@$external_ip
done

Atenção: Abra 3 janelas novas de shell , se não tiver ambiente gráfico use o TMUX, ou faça uma por vez
Em cada janela nova, o comando acima gerou os comandos ssh para executar em cada janela ssh que irá conetar no worker-0, worker-1 e worker-2
Execute os comandos abaixo em cada uma das janelas:

Provisionando o Worker (Nó)

O binário socat ativa o suporte para o comando kubectl port-forward que iremos usar adiante.

sudo apt update && sudo apt install -y socat conntrack ipset

Baixando os executáveis para o Worker

wget -q --show-progress --https-only --timestamping \
  https://github.com/kubernetes-sigs/cri-tools/releases/download/v1.18.0/crictl-v1.18.0-linux-amd64.tar.gz \
  https://storage.googleapis.com/kubernetes-the-hard-way/runsc \
  https://github.com/opencontainers/runc/releases/download/v1.0.0-rc91/runc.amd64 \
  https://github.com/containernetworking/plugins/releases/download/v0.8.6/cni-plugins-linux-amd64-v0.8.6.tgz \
  https://github.com/containerd/containerd/releases/download/v1.3.6/containerd-1.3.6-linux-amd64.tar.gz \
  https://storage.googleapis.com/kubernetes-release/release/v1.18.6/bin/linux/amd64/kubectl \
  https://storage.googleapis.com/kubernetes-release/release/v1.18.6/bin/linux/amd64/kube-proxy \
  https://storage.googleapis.com/kubernetes-release/release/v1.18.6/bin/linux/amd64/kubelet

chmod +x *.tar.gz *.tgz

sudo mkdir -p \
  /etc/cni/net.d \
  /opt/cni/bin \
  /var/lib/kubelet \
  /var/lib/kube-proxy \
  /var/lib/kubernetes \
  /var/run/kubernetes

chmod +x kubectl kube-proxy kubelet runc.amd64 runsc

sudo mv runc.amd64 runc

sudo mv kubectl kube-proxy kubelet runc runsc /usr/local/bin/

sudo tar -xvf crictl-v1.18.0-linux-amd64.tar.gz -C /usr/local/bin/

sudo tar -xvf cni-plugins-linux-amd64-v0.8.6.tgz -C /opt/cni/bin/

sudo tar -xvf containerd-1.3.6-linux-amd64.tar.gz

sudo mv bin/* /bin/

Configurando CNI

Recupere o intervalo de pod CIDR para o worker atual:

POD_CIDR=$(curl -s http://169.254.169.254/latest/user-data/ \
  | tr "|" "\n" | grep "^pod-cidr" | cut -d"=" -f2)

echo "${POD_CIDR}"

cat <<EOF | sudo tee /etc/cni/net.d/10-bridge.conf
{
    "cniVersion": "0.3.1",
    "name": "bridge",
    "type": "bridge",
    "bridge": "cnio0",
    "isGateway": true,
    "ipMasq": true,
    "ipam": {
        "type": "host-local",
        "ranges": [
          [{"subnet": "${POD_CIDR}"}]
        ],
        "routes": [{"dst": "0.0.0.0/0"}]
    }
}
EOF

cat /etc/cni/net.d/10-bridge.conf

cat <<EOF | sudo tee /etc/cni/net.d/99-loopback.conf
{
    "cniVersion": "0.3.1",
    "name": "lo",
    "type": "loopback"
}
EOF

cat /etc/cni/net.d/99-loopback.conf

Configurando Containerd

sudo mkdir -p /etc/containerd/

cat <<EOF | sudo tee /etc/containerd/config.toml
[plugins]
  [plugins.cri.containerd]
    snapshotter = "overlayfs"
    [plugins.cri.containerd.default_runtime]
      runtime_type = "io.containerd.runtime.v1.linux"
      runtime_engine = "/usr/local/bin/runc"
      runtime_root = ""
    [plugins.cri.containerd.untrusted_workload_runtime]
      runtime_type = "io.containerd.runtime.v1.linux"
      runtime_engine = "/usr/local/bin/runsc"
      runtime_root = "/run/containerd/runsc"
EOF

cat /etc/containerd/config.toml

cat <<EOF | sudo tee /etc/systemd/system/containerd.service
[Unit]
Description=containerd container runtime
Documentation=https://containerd.io
After=network.target

[Service]
ExecStartPre=/sbin/modprobe overlay
ExecStart=/bin/containerd
Restart=always
RestartSec=5
Delegate=yes
KillMode=process
OOMScoreAdjust=-999
LimitNOFILE=1048576
LimitNPROC=infinity
LimitCORE=infinity

[Install]
WantedBy=multi-user.target
EOF

Configurando Kubelet

WORKER_NAME=$(curl -s http://169.254.169.254/latest/user-data/ \
  | tr "|" "\n" | grep "^name" | cut -d"=" -f2)

echo "${WORKER_NAME}"
    
sudo mv ${WORKER_NAME}-key.pem ${WORKER_NAME}.pem /var/lib/kubelet/

sudo mv ${WORKER_NAME}.kubeconfig /var/lib/kubelet/kubeconfig

sudo mv ca.pem /var/lib/kubernetes/

cat <<EOF | sudo tee /var/lib/kubelet/kubelet-config.yaml
kind: KubeletConfiguration
apiVersion: kubelet.config.k8s.io/v1beta1
authentication:
  anonymous:
    enabled: false
  webhook:
    enabled: true
  x509:
    clientCAFile: "/var/lib/kubernetes/ca.pem"
authorization:
  mode: Webhook
clusterDomain: "cluster.local"
clusterDNS:
  - "10.32.0.10"
podCIDR: "${POD_CIDR}"
runtimeRequestTimeout: "15m"
tlsCertFile: "/var/lib/kubelet/${WORKER_NAME}.pem"
tlsPrivateKeyFile: "/var/lib/kubelet/${WORKER_NAME}-key.pem"
resolvConf: "/run/systemd/resolve/resolv.conf"
EOF

cat /var/lib/kubelet/kubelet-config.yaml

cat <<EOF | sudo tee /etc/systemd/system/kubelet.service
[Unit]
Description=Kubernetes Kubelet
Documentation=https://github.com/kubernetes/kubernetes
After=containerd.service
Requires=containerd.service

[Service]
ExecStart=/usr/local/bin/kubelet \\
  --config=/var/lib/kubelet/kubelet-config.yaml \\
  --container-runtime=remote \\
  --container-runtime-endpoint=unix:///var/run/containerd/containerd.sock \\
  --image-pull-progress-deadline=2m \\
  --kubeconfig=/var/lib/kubelet/kubeconfig \\
  --network-plugin=cni \\
  --register-node=true \\
  --v=2
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target
EOF

cat /etc/systemd/system/kubelet.service

Configurando Proxy

sudo mv kube-proxy.kubeconfig /var/lib/kube-proxy/kubeconfig

cat <<EOF | sudo tee /var/lib/kube-proxy/kube-proxy-config.yaml
kind: KubeProxyConfiguration
apiVersion: kubeproxy.config.k8s.io/v1alpha1
clientConnection:
  kubeconfig: "/var/lib/kube-proxy/kubeconfig"
mode: "iptables"
clusterCIDR: "10.200.0.0/16"
EOF

cat /var/lib/kube-proxy/kube-proxy-config.yaml


cat <<EOF | sudo tee /etc/systemd/system/kube-proxy.service
[Unit]
Description=Kubernetes Kube Proxy
Documentation=https://github.com/kubernetes/kubernetes

[Service]
ExecStart=/usr/local/bin/kube-proxy \\
  --config=/var/lib/kube-proxy/kube-proxy-config.yaml
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target
EOF

cat /etc/systemd/system/kube-proxy.service

Iniciando o Serviço

sudo systemctl daemon-reload

sudo systemctl enable containerd kubelet kube-proxy

sudo systemctl start containerd kubelet kube-proxy

Atenção: O comando abaixo deve ser executado na sua máquina local
Pode fechar as janelas dos workers

Verificando os Workers

external_ip=$(aws ec2 describe-instances --filters \
    "Name=tag:Name,Values=controller-0" \
    "Name=instance-state-name,Values=running" \
    --output text --query 'Reservations[].Instances[].PublicIpAddress')

echo "$external_ip"

ssh -i kubernetes.id_rsa ubuntu@${external_ip}

kubectl get nodes --kubeconfig admin.kubeconfig

exit

Resultado Esperado

NAME             STATUS   ROLES    AGE   VERSION
ip-10-0-1-20   Ready       51s   v1.18.6
ip-10-0-1-21   Ready       51s   v1.18.6
ip-10-0-1-22   Ready       51s   v1.18.6