# 部署计算节点

本部分将会部署三个 Kubernetes Worker 节点。每个节点上将会安装以下服务：[runc](https://github.com/opencontainers/runc), [gVisor](https://github.com/google/gvisor), [container networking plugins](https://github.com/containernetworking/cni), [containerd](https://github.com/containerd/containerd), [kubelet](https://kubernetes.io/docs/admin/kubelet), 和 [kube-proxy](https://kubernetes.io/docs/concepts/cluster-administration/proxies)。

## 事前准备

以下命令需要在所有 worker 节点上面都运行一遍，包括 `worker-0`, `worker-1` 和 `worker-2`。可以使用 `gcloud` 命令登录到 worker 节点上，比如

```bash
gcloud compute ssh worker-0
```

可以使用 tmux 同时登录到三个 Worker 节点上，加快部署步骤。

## 部署 Kubernetes Worker 节点

安装 OS 依赖组件：

```bash
sudo apt-get update
sudo apt-get -y install socat conntrack ipset
```

> socat 命令用于支持 `kubectl port-forward` 命令。

### 禁止 Swap

```bash
sudo swapoff -a
```

### 下载并安装 worker 二进制文件

```bash
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://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
```

创建安装目录：

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

安装 worker 二进制文件

```bash
{
  mkdir containerd
  tar -xvf crictl-v1.18.0-linux-amd64.tar.gz
  tar -xvf containerd-1.3.6-linux-amd64.tar.gz -C containerd
  sudo tar -xvf cni-plugins-linux-amd64-v0.8.6.tgz -C /opt/cni/bin/
  sudo mv runc.amd64 runc
  chmod +x crictl kubectl kube-proxy kubelet runc
  sudo mv crictl kubectl kube-proxy kubelet runc /usr/local/bin/
  sudo mv containerd/bin/* /bin/
}
```

### 配置 CNI 网路

查询当前计算节点的 Pod CIDR 范围：

```bash
POD_CIDR=$(curl -s -H "Metadata-Flavor: Google" \
  http://metadata.google.internal/computeMetadata/v1/instance/attributes/pod-cidr)
```

生成 `bridge` 网络插件配置文件

```bash
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
```

生成 `loopback` 网络插件配置文件

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

### 配置 containerd

```bash
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 = ""
EOF

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
```

### 配置 Kubelet

```bash
{
  sudo mv ${HOSTNAME}-key.pem ${HOSTNAME}.pem /var/lib/kubelet/
  sudo mv ${HOSTNAME}.kubeconfig /var/lib/kubelet/kubeconfig
  sudo mv ca.pem /var/lib/kubernetes/
}
```

生成 `kubelet.service` systemd 配置文件：

```bash
# The resolvConf configuration is used to avoid loops when using CoreDNS for service discovery on systems running systemd-resolved.
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: "${POD_CIDR}"
resolvConf: "/run/systemd/resolve/resolv.conf"
runtimeRequestTimeout: "15m"
tlsCertFile: "/var/lib/kubelet/${HOSTNAME}.pem"
tlsPrivateKeyFile: "/var/lib/kubelet/${HOSTNAME}-key.pem"
EOF

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
```

### 配置 Kube-Proxy

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

生成 `kube-proxy.service` systemd 配置文件：

```bash
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 <<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
```

### 启动 worker 服务

```bash
sudo systemctl daemon-reload
sudo systemctl enable containerd kubelet kube-proxy
sudo systemctl start containerd kubelet kube-proxy
```

> 记得在所有 worker 节点上面都运行一遍，包括 `worker-0`, `worker-1` 和 `worker-2`。

## 验证

登入任意一台控制节点查询 Nodes 列表

```bash
gcloud compute ssh controller-0 \
  --command "kubectl get nodes --kubeconfig admin.kubeconfig"
```

输出为

```bash
NAME       STATUS   ROLES    AGE   VERSION
worker-0   Ready    <none>   24s   v1.18.6
worker-1   Ready    <none>   24s   v1.18.6
worker-2   Ready    <none>   24s   v1.18.6
```

下一步：[配置 Kubectl](https://kubernetes.feisky.xyz/setup/k8s-hard-way/10-configuring-kubectl)。