kubeadm 安装单master集群

环境准备

系统及软件版本

kubernetes version: v1.16.3

组件	版本	说明
Centos	7.7	操作系统
kubeadm	v1.16.3	集群部署工具
etcd	3.3.15	存储数据库
calico	v3.14.0	CNI 网络插件
docker	18.09.9	CRI Runtime
metallb	v0.8.3	穷人版 LoadBalancer

主机列表

hostname	IP Address	components
k8s-master	10.64.144.100	kube-apiserver,kube-controller-manager,kube-scheduler,etcd,kubelet,flannel,docker
k8s-node01	10.64.144.101	kube-proxy,kubelet,flannel,docker
k8s-node02	10.64.144.102	kube-proxy,kubelet,flannel,docker
k8s-node03	10.64.144.103	kube-proxy,kubelet,flannel,docker
k8s-node04	10.64.144.104	kube-proxy,kubelet,flannel,docker
k8s-node05	10.64.144.105	kube-proxy,kubelet,flannel,docker
k8s-node06	10.64.144.106	kube-proxy,kubelet,flannel,docker

网络规划

功能	网段
Pod 网络	172.16.0.0/16
Service 网络	10.96.0.0/12
DNS 地址	10.96.0.10
LoadBalance	10.64.144.150~10.64.144.200

系统初始化

所有节点上都需要操作

配置 hosts 同步

$ cat > /etc/hosts <<EOF
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
10.64.144.100   k8s-master
10.64.144.101   k8s-node01
10.64.144.102   k8s-node02
10.64.144.103   k8s-node03
10.64.144.104   k8s-node04
10.64.144.105   k8s-node05
10.64.144.106   k8s-node06
EOF

设置主机名

hostnamectl set-hostname k8s-master # 分别设置所有节点的主机名

更新系统

yum update -y

更新内核

安装稳定版主线内核

rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
yum install -y https://www.elrepo.org/elrepo-release-7.el7.elrepo.noarch.rpm
yum install -y --enablerepo=elrepo-kernel kernel-ml kernel-ml-headers kernel-ml-devel

查看系统中已安装的内核版本

$ awk -F\' '$1=="menuentry " {print i++ " : " $2}' /etc/grub2.cfg
0 : CentOS Linux (5.6.13-1.el7.elrepo.x86_64) 7 (Core)
1 : CentOS Linux (3.10.0-1062.4.1.el7.x86_64) 7 (Core)
2 : CentOS Linux (3.10.0-957.el7.x86_64) 7 (Core)
3 : CentOS Linux (0-rescue-4097349c950a4862a8fab2587d598af7) 7 (Core)

切换默认内核

0 为上面列出的序号，比如我这里 0 代表 5.6.13 这个版本的内核

$ grub2-set-default 0
$ grub2-mkconfig -o /boot/grub2/grub.cfg
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-5.6.13-1.el7.elrepo.x86_64
Found initrd image: /boot/initramfs-5.6.13-1.el7.elrepo.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-1062.4.1.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-1062.4.1.el7.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-957.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-957.el7.x86_64.img
Found linux image: /boot/vmlinuz-0-rescue-4097349c950a4862a8fab2587d598af7
Found initrd image: /boot/initramfs-0-rescue-4097349c950a4862a8fab2587d598af7.img
done

配置网卡驱动(可选)

实验环境中由于使用的是普通 PC，板载网卡为 realtek r8168/r8169, 这个网卡在 5.x 版本内核中由于缺少加载 realtek.ko 模块会造成无法正常识别到网卡的情况

$ mkinitrd --force --preload realtek /boot/initramfs-`uname -r`.img `uname -r`
$ lsinitrd /boot/initramfs-`uname -r`.img | grep realtek
Arguments: -f --add-drivers ' realtek'
...
-rwxr--r--   1 root     root       127880 Jan  7 16:21 usr/lib/modules/5.6.13-1.el7.elrepo.x86_64/kernel/drivers/net/ethernet/realtek/r8169.ko
-rwxr--r--   1 root     root        27360 Jan  7 16:21 usr/lib/modules/5.6.13-1.el7.elrepo.x86_64/kernel/drivers/net/phy/realtek.ko

确保有加载 realtek.ko 和 r8169.ko 模块

重启后验证内核版本

$ uname -r
5.6.13-1.el7.elrepo.x86_64

禁用 SELinux

如果不禁用 selinux，挂载目录会出现 Permission deined 错误

sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config  # 永久关闭
setenforce 0  # 临时关闭

禁用 swap

swapoff -a
sed -i -r 's/(.+ swap .*)/# \1/' /etc/fstab
sysctl -w vm.swappiness=0
cat > /etc/sysctl.d/swap.conf <<EOF
vm.swappiness=0
EOF
sysctl -p /etc/sysctl.d/swap.conf

禁用不需要的服务

如果选择不关闭firewalld，请参考官方文档中放行相应的端口 check-required-ports

最少化安装的 Centos 中貌似没有安装 dnsmasq，如果有安装则需要将其禁用，否则它会把节点上的 DNS server 设置为 127.0.0.1,将会导致 Docker 无法解析域名

systemctl disable --now firewalld NetworkManager dnsmasq

安装必要工具

kube-proxy 的 ipvs 模式下依赖ipvsadm,ipset用于配置及管理规则

kubectl port-forward命令依赖socat做端口转发

yum install -y ipvsadm ipset sysstat conntrack libseccomp socat wget git jq curl

优化系统内核

$ cat > /etc/sysctl.d/k8s.conf <<EOF
# https://github.com/moby/moby/issues/31208
# ipvsadm -l --timout
# 修复ipvs模式下长连接timeout问题 小于900即可
net.ipv4.tcp_keepalive_time = 600
net.ipv4.tcp_keepalive_intvl = 30
net.ipv4.tcp_keepalive_probes = 10
# 关闭ipv6
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
net.ipv4.neigh.default.gc_stale_time = 120
net.ipv4.conf.all.rp_filter = 0
net.ipv4.conf.default.rp_filter = 0
net.ipv4.conf.default.arp_announce = 2
net.ipv4.conf.lo.arp_announce = 2
net.ipv4.conf.all.arp_announce = 2
# 开启路由转发
net.ipv4.ip_forward = 1
net.ipv4.tcp_max_tw_buckets = 5000
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_syn_backlog = 1024
net.ipv4.tcp_synack_retries = 2
# 开启 bridge-netfilter, 使用iptables规则可以作用于bridge模式
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.bridge.bridge-nf-call-arptables = 1
net.netfilter.nf_conntrack_max = 2310720
fs.inotify.max_user_watches=89100
fs.may_detach_mounts = 1
fs.file-max = 52706963
fs.nr_open = 52706963
vm.overcommit_memory=1
vm.panic_on_oom=0
EOF
$ sysctl --system  # 使配置生效

开启 ipvs 支持

如果内核版本小于 4.19, 需要将 nf_conntrack 修改为 nf_conntrack_ipv4

# 临时生效
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack

# 永久生效
$ cat > /etc/sysconfig/modules/ipvs.modules <<'EOF'
#!/bin/sh
modules=(
ip_vs
ip_vs_rr
ip_vs_wrr
ip_vs_sh
nf_conntrack_ipv4
br_netfilter
)
for mod in ${modules[@]}
do
  /sbin/modinfo -F filename ${mod} > /dev/null 2>&1
  if [ $? -eq 0 ]
  then
      /sbin/modprobe ${mod}
  fi
done
EOF
chmod +x /etc/sysconfig/modules/ipvs.modules

# 检查内核模块是否已经加载
$ lsmod | grep ip_vs
ip_vs_sh               12688  0
ip_vs_wrr              12697  0
ip_vs_rr               12600  4
ip_vs                 145497  10 ip_vs_rr,ip_vs_sh,ip_vs_wrr
nf_conntrack          139224  7 ip_vs,nf_nat,nf_nat_ipv4,xt_conntrack,nf_nat_masquerade_ipv4,nf_conntrack_netlink,nf_conntrack
libcrc32c              12644  4 xfs,ip_vs,nf_nat,nf_conntrack

时间同步

所有节点配置为同一时区，并使用 chrony 同步节点的时间

$ ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
$ echo "Asia/Shanghai" > /etc/timezone
$ yum install chrony -y
$ cat > /etc/chrony.conf <<EOF
server ntp.aliyun.com iburst
stratumweight 0
driftfile /var/lib/chrony/drift
rtcsync
makestep 10 3
bindcmdaddress 127.0.0.1
bindcmdaddress ::1
keyfile /etc/chrony.keys
commandkey 1
generatecommandkey
logchange 0.5
logdir /var/log/chrony
EOF
$ systemctl enable --now chronyd

运行 docker 检测脚本

docker 官方提供了脚本用于检查内核相关配置

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
\$ curl -fsSL <https://raw.githubusercontent.com/moby/moby/master/contrib/check-config.sh> | bash -s
info: reading kernel config from /boot/config-3.10.0-1062.4.3.el7.x86_64 ...

Generally Necessary:
...

Optional Features:

- CONFIG_USER_NS: enabled
  (RHEL7/CentOS7: User namespaces disabled; add 'user_namespace.enable=1' to boot command line)
- CONFIG_SECCOMP: enabled
  ...
  

如上高亮行所示，开启 user_namespace

$ grubby --args="user_namespace.enable=1" --update-kernel="$(grubby --default-kernel)"
$ grep user_namespace /etc/grub2.cfg
        linux16 /vmlinuz-5.6.13-1.el7.elrepo.x86_64 root=/dev/mapper/centos-root ro crashkernel=auto rd.lvm.lv=centos/root rhgb quiet user_namespace.enable=1

重启系统

重启系统以使配置生效

systemctl reboot

安装 Docker

所有节点上均需配置

虽然 Kubernetes 支持多种容器运行环境，如 Docker, Containerd, CRI-O 等，但目前 Docker 还是主流

关于容器运行环境可以参考官方文档 Container Runntimes

支持的 Docker 版本列表请查看官方 CHANGELOG 搜索 The list of validated docker versions 关键字

安装

官方推荐使用 18.06.2, 我这里使用的是 18.09.9

Docker 官方的 yum 源在国内可能会访问不到，这里使用了阿里云的镜像源

yum install -y yum-utils device-mapper-persistent-data lvm2
export VERSION=18.09
curl -fsSL https://get.docker.com | bash -s docker --mirror Aliyun

修改配置文件

主要修改以下几个参数:

native.cgroupdriver: 官方推荐使用 systemd 来管理 cgroup,且必须与 kubelet 的--cgroup-driver参数一致
storage-driver: 存储驱动，overlay2 会比其他驱动更好的性能。如果文件系统为XFS，请确保ftype=1(可使用 xfs_info 查看),否则 docker 会无法启动，报错信息Error starting daemon: error initializing graphdriver: overlay2: the backing xfs filesystem is formatted without d_type support, which leads to incorrect behavior. Reformat the filesystem with ftype=1 to enable d_type support. Backing filesystems without d_type support are not supported.
registry-mirrors: 加速从 dockerhub 拉取镜像

mkdir /etc/docker
cat > /etc/docker/daemon.json <<EOF
{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "registry-mirrors": ["https://8jg6za8m.mirror.aliyuncs.com"],
  "storage-driver": "overlay2",
  "storage-opts": [
    "overlay2.override_kernel_check=true"
  ],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m",
    "max-file": "3"
  }
}
EOF

启动并检查配置是否生效

$ systemctl enable --now docker
Created symlink from /etc/systemd/system/multi-user.target.wants/docker.service to /usr/lib/systemd/system/docker.service.
$ docker version
Client:
 Version:           18.09.9
 API version:       1.39
 Go version:        go1.11.13
 Git commit:        039a7df9ba
 Built:             Wed Sep  4 16:51:21 2019
 OS/Arch:           linux/amd64
 Experimental:      false

Server: Docker Engine - Community
 Engine:
  Version:          18.09.9
  API version:      1.39 (minimum version 1.12)
  Go version:       go1.11.13
  Git commit:       039a7df
  Built:            Wed Sep  4 16:22:32 2019
  OS/Arch:          linux/amd64
  Experimental:     false
$ docker info
Containers: 0
 Running: 0
 Paused: 0
 Stopped: 0
Images: 0
Server Version: 18.09.9
Storage Driver: overlay2
 Backing Filesystem: xfs
 Supports d_type: true
 Native Overlay Diff: true
Logging Driver: json-file
Cgroup Driver: systemd
Plugins:
 Volume: local
 Network: bridge host macvlan null overlay
 Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: b34a5c8af56e510852c35414db4c1f4fa6172339
runc version: 3e425f80a8c931f88e6d94a8c831b9d5aa481657
init version: fec3683
Security Options:
 seccomp
  Profile: default
Kernel Version: 5.6.13-1.el7.elrepo.x86_64
Operating System: CentOS Linux 7 (Core)
OSType: linux
Architecture: x86_64
CPUs: 4
Total Memory: 15.39GiB
Name: k8s-master
ID: BI53:OQC7:QV6C:SP3N:FBTT:N5ST:MK3I:CGLJ:X2JX:CJOH:CBEE:4GG2
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
 127.0.0.0/8
Registry Mirrors:
 https://8jg6za8m.mirror.aliyuncs.com/
Live Restore Enabled: false
Product License: Community Engine

安装 kubernetes 相关工具

所有节点上操作

添加阿里云 YUM 源

默认官方的源在国内环境下可能会访问不到

cat > /etc/yum.repos.d/kubernetes.repo <<EOF
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

查看支持的版本列表

$ yum --disablerepo="*" --enablerepo="kubernetes" list available --showduplicates  | grep "1.16"
kubeadm.x86_64                       1.16.0-0                         kubernetes
kubeadm.x86_64                       1.16.1-0                         kubernetes
kubeadm.x86_64                       1.16.2-0                         kubernetes
kubeadm.x86_64                       1.16.3-0                         kubernetes
kubectl.x86_64                       1.16.0-0                         kubernetes
kubectl.x86_64                       1.16.1-0                         kubernetes
kubectl.x86_64                       1.16.2-0                         kubernetes
kubectl.x86_64                       1.16.3-0                         kubernetes
kubelet.x86_64                       1.16.0-0                         kubernetes
kubelet.x86_64                       1.16.1-0                         kubernetes
kubelet.x86_64                       1.16.2-0                         kubernetes
kubelet.x86_64                       1.16.3-0                         kubernetes

安装 kubeadm、kubectl、kubelet 工具

本次安装 1.16.3 版本

worker 节点可以不安装 kubectl

yum install kubeadm-1.16.3 kubectl-1.16.3 kubelet-1.16.3 -y

添加 kubelet 开机自启动

$ systemctl enable --now kubelet
Created symlink from /etc/systemd/system/multi-user.target.wants/kubelet.service to /usr/lib/systemd/system/kubelet.service.
$ systemctl status kubelet
● kubelet.service - kubelet: The Kubernetes Node Agent
   Loaded: loaded (/usr/lib/systemd/system/kubelet.service; enabled; vendor preset: disabled)
  Drop-In: /usr/lib/systemd/system/kubelet.service.d
           └─10-kubeadm.conf
   Active: activating (auto-restart) (Result: exit-code) since Thu 2019-11-21 10:27:34 CST; 898ms ago
     Docs: https://kubernetes.io/docs/
  Process: 3947 ExecStart=/usr/bin/kubelet $KUBELET_KUBECONFIG_ARGS $KUBELET_CONFIG_ARGS $KUBELET_KUBEADM_ARGS $KUBELET_EXTRA_ARGS (code=exited, status=255)
 Main PID: 3947 (code=exited, status=255)

Nov 21 10:27:34 k8s-master systemd[1]: Unit kubelet.service entered failed state.
Nov 21 10:27:34 k8s-master systemd[1]: kubelet.service failed.

如上查看服务状态你会发现启动失败，不过没关系，这里可以暂时忽略，因为我们还没开始初始化集群，所以还没有生成kubelet的配置文件

如果 enable 时提示 Unit kubelet.service could not be found.，执行systemctl daemon-reload重载配置就可以了

初始化集群

在 master 上操作

生成 kubeadm 配置文件

生成默认配置

kubeadm config print init-defaults --component-configs KubeProxyConfiguration,KubeletConfiguration > kubeadm-config.yaml

修改配置

主要改动如下:

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
apiVersion: kubeadm.k8s.io/v1beta2
bootstrapTokens:

- groups:
  - system:bootstrappers:kubeadm:default-node-token
    token: d7cb0e.605fb37fed0895d3 # 使用命令 echo "$(openssl rand -hex 3).$(openssl rand -hex 8)" 生成
    ttl: 24h0m0s
    usages:
  - signing
  - authentication
    kind: InitConfiguration
    localAPIEndpoint:
    advertiseAddress: 10.64.144.100 # Master 节点的本机 IP 地址
    bindPort: 6443
    nodeRegistration:
    criSocket: /var/run/dockershim.sock
    name: k8s-master
    taints:
  - effect: NoSchedule
    key: node-role.kubernetes.io/master

---

apiServer:
timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns:
type: CoreDNS
etcd:
local:
dataDir: /var/lib/etcd
imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers # 由于默认的`k8s.gcr.io`在国内无法正常访问，这里使用阿里云的源代替
kind: ClusterConfiguration
kubernetesVersion: v1.16.3 # kubernetes 版本
networking:
dnsDomain: cluster.local
serviceSubnet: 10.96.0.0/12 # 集群 service 的网段
podSubnet: 172.16.0.0/16 # 集群 pod 网段
scheduler: {}

---

apiVersion: kubeproxy.config.k8s.io/v1alpha1
bindAddress: 0.0.0.0
clientConnection:
acceptContentTypes: ""
burst: 10
contentType: application/vnd.kubernetes.protobuf
kubeconfig: /var/lib/kube-proxy/kubeconfig.conf
qps: 5
clusterCIDR: "172.16.0.0/16" # 集群 pod 的网段，需要与后续部署的网络插件一致
configSyncPeriod: 15m0s
conntrack:
maxPerCore: 32768
min: 131072
tcpCloseWaitTimeout: 1h0m0s
tcpEstablishedTimeout: 24h0m0s
enableProfiling: false
healthzBindAddress: 0.0.0.0:10256
hostnameOverride: ""
iptables:
masqueradeAll: false
masqueradeBit: 14
minSyncPeriod: 0s
syncPeriod: 30s
ipvs:
excludeCIDRs: null
minSyncPeriod: 0s
scheduler: ""
strictARP: false
syncPeriod: 30s
kind: KubeProxyConfiguration
metricsBindAddress: 0.0.0.0:10249
mode: "ipvs" # Kube-Proxy 使用 ipvs 模式， 1.11 之后的版本默认使用 ipvs 代替了 iptables。如果节点上没有启用 ipvs 内核模块，会自动降级为 iptables
nodePortAddresses: null
oomScoreAdj: -999
portRange: ""
udpIdleTimeout: 250ms
winkernel:
enableDSR: false
networkName: ""
sourceVip: ""

---

address: 0.0.0.0
apiVersion: kubelet.config.k8s.io/v1beta1
authentication:
anonymous:
enabled: false
webhook:
cacheTTL: 2m0s
enabled: true
x509:
clientCAFile: /etc/kubernetes/pki/ca.crt
authorization:
mode: Webhook
webhook:
cacheAuthorizedTTL: 5m0s
cacheUnauthorizedTTL: 30s
cgroupDriver: systemd # cgroup 管理方式，需要与 docker 中的`native.cgroupdriver`一致，推荐使用 systemd
cgroupsPerQOS: true
clusterDNS:

- 10.96.0.10 # 集群中 CoreDNS 的 Service IP 地址，需要在上面配置`networking.serviceSubnet`子网中
  clusterDomain: cluster.local
  configMapAndSecretChangeDetectionStrategy: Watch
  containerLogMaxFiles: 5
  containerLogMaxSize: 10Mi
  contentType: application/vnd.kubernetes.protobuf
  cpuCFSQuota: true
  cpuCFSQuotaPeriod: 100ms
  cpuManagerPolicy: none
  cpuManagerReconcilePeriod: 10s
  enableControllerAttachDetach: true
  enableDebuggingHandlers: true
  enforceNodeAllocatable:
- pods
  eventBurst: 10
  eventRecordQPS: 5
  evictionHard:
  imagefs.available: 15%
  memory.available: 100Mi
  nodefs.available: 10%
  nodefs.inodesFree: 5%
  evictionPressureTransitionPeriod: 5m0s
  failSwapOn: true
  fileCheckFrequency: 20s
  hairpinMode: promiscuous-bridge
  healthzBindAddress: 127.0.0.1
  healthzPort: 10248
  httpCheckFrequency: 20s
  imageGCHighThresholdPercent: 85
  imageGCLowThresholdPercent: 80
  imageMinimumGCAge: 2m0s
  iptablesDropBit: 15
  iptablesMasqueradeBit: 14
  kind: KubeletConfiguration
  kubeAPIBurst: 10
  kubeAPIQPS: 5
  makeIPTablesUtilChains: true
  maxOpenFiles: 1000000
  maxPods: 110
  nodeLeaseDurationSeconds: 40
  nodeStatusReportFrequency: 1m0s
  nodeStatusUpdateFrequency: 10s
  oomScoreAdj: -999
  podPidsLimit: -1
  port: 10250
  registryBurst: 10
  registryPullQPS: 5
  resolvConf: /etc/resolv.conf
  rotateCertificates: true
  runtimeRequestTimeout: 2m0s
  serializeImagePulls: true
  staticPodPath: /etc/kubernetes/manifests
  streamingConnectionIdleTimeout: 4h0m0s
  syncFrequency: 1m0s
  topologyManagerPolicy: none
  volumeStatsAggPeriod: 1m0s
  

下载所需镜像(可选)

初始化的时候也会自动下载所有的镜像,提前下载好镜像可减少后续初始化时的等待时间

$ kubeadm config images list --config kubeadm-config.yaml # 查看镜像列表
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.16.3
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.16.3
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.16.3
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.16.3
registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1
registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.3.15-0
registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.6.2
$ kubeadm config images pull --config kubeadm-config.yaml # 下载镜像
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.16.3
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.16.3
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.16.3
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.16.3
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.3.15-0
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.6.2

初始化

$ kubeadm init --config kubeadm-config.yaml
[init] Using Kubernetes version: v1.16.3
[preflight] Running pre-flight checks
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Activating the kubelet service
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [k8s-master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 10.64.144.100]
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "front-proxy-ca" certificate and key
[certs] Generating "front-proxy-client" certificate and key
[certs] Generating "etcd/ca" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [k8s-master localhost] and IPs [10.64.144.100 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [k8s-master localhost] and IPs [10.64.144.100 127.0.0.1 ::1]
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "sa" key and public key
[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
[kubeconfig] Writing "admin.conf" kubeconfig file
[kubeconfig] Writing "kubelet.conf" kubeconfig file
[kubeconfig] Writing "controller-manager.conf" kubeconfig file
[kubeconfig] Writing "scheduler.conf" kubeconfig file
[control-plane] Using manifest folder "/etc/kubernetes/manifests"
[control-plane] Creating static Pod manifest for "kube-apiserver"
[control-plane] Creating static Pod manifest for "kube-controller-manager"
[control-plane] Creating static Pod manifest for "kube-scheduler"
[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests". This can take up to 4m0s
[apiclient] All control plane components are healthy after 34.001666 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.16" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --upload-certs
[mark-control-plane] Marking the node k8s-master as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node k8s-master as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: d7cb0e.605fb37fed0895d3
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy

Your Kubernetes control-plane has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 10.64.144.100:6443 --token d7cb0e.605fb37fed0895d3 \
    --discovery-token-ca-cert-hash sha256:dcabbe4b86492eb5da1f22c2a24fb1b5698557185abd481d858eda25a8d926aa

如上提示有三条信息

需要配置 kubeconfig ,以便 kubectl 可以操作集群
需要选择一个网络插件进行安装，以使集群可以连接网络通信
保存最后一条命令，后续 worker 节点加入集群时会用到

配置 kubeconfig

按上面提示操作就行

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

使用 kubectl 查看集群当前状态，顺便检验 kubeconfig 是否配置正确

$ kubectl get pods -n kube-system # 查看系统组件运行状态
NAME                                 READY   STATUS    RESTARTS   AGE
coredns-67c766df46-5d5pp             0/1     Pending   0          4m40s
coredns-67c766df46-kjd9f             0/1     Pending   0          4m40s
etcd-k8s-master                      1/1     Running   0          3m34s
kube-apiserver-k8s-master            1/1     Running   0          3m41s
kube-controller-manager-k8s-master   1/1     Running   0          3m44s
kube-proxy-r2w74                     1/1     Running   0          4m39s
kube-scheduler-k8s-master            1/1     Running   0          3m44s
$ kubectl get nodes  # 查看节点状态
NAME         STATUS     ROLES    AGE    VERSION
k8s-master   NotReady   master   5m6s   v1.16.3

以上两个 coredns 的 pod 处于 Pending 状态，以及 master 节点 NotReady 状态，是由于我们集群中还没有安装可通信的网络插件，暂时先忽略即可

加入 worker 节点到集群

在 woker 节点上操作

还记得kubeadm init后输出的最后一条命令吗，worker 节点上只需要执行这一条命令就行了

$ kubeadm join 10.64.144.100:6443 --token d7cb0e.605fb37fed0895d3 --discovery-token-ca-cert-hash sha256:dcabbe4b86492eb5da1f22c2a24fb1b5698557185abd481d858eda25a8d926aa
[preflight] Running pre-flight checks
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.16" ConfigMap in the kube-system namespace
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Activating the kubelet service
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...

This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.

Run 'kubectl get nodes' on the control-plane to see this node join the cluster.

master 节点上操作

所有节点上都执行后，在 master 上查看节点状态

$ kubectl get nodes
NAME         STATUS     ROLES    AGE   VERSION
k8s-master   NotReady   master   18m   v1.16.3
k8s-node01   NotReady   <none>   57s   v1.16.3
k8s-node02   NotReady   <none>   20s   v1.16.3
k8s-node03   NotReady   <none>   9s    v1.16.3
k8s-node04   NotReady   <none>   2s    v1.16.3
k8s-node05   NotReady   <none>   2s    v1.16.3
k8s-node06   NotReady   <none>   2s    v1.16.3

到目前为止，我们集群已经创建好的，但是节点间还不能相互通信，所以状态都还是NotReady

接下来我们将选择一款适合自己的网络插件来部署

安装 CNI 网络插件

所有操作均在 master 节点上

注意事项及支持的网络插件列表请参考官网 Installing a pod network add-on 及 Networking and Network Policy

关于各 CNI 插件的功能对比可以参考 Kubernetes CNI 网络最强对比：Flannel、Calico、Canal 和 Weave 和性能基准测试 K8S 网络插件（CNI）超过 10Gbit/s 的基准测试结果

由于我们实验环境是二层可达，所以选用 Calico BGP 模式，如果二层不可达，可以考虑使用 Calico IPIP 或者 Flannel VXLAN

下载 calico.yaml

curl -O https://docs.projectcalico.org/manifests/calico.yaml

默认情况下，不做修改也可以，calico 会自动发现 cluster cidr, 这里我们自行修改下

主要改动如下:

CALICO_IPV4POOL_IPIP 设置为 Never，关闭 IPIP 模式
CALICO_IPV4POOL_CIDR 设置为 172.16.0.0/16，对应 kubeadm 中的 cluster-cidr

部署

kubectl apply -f caclico.yml

通过 calicoctl 查看 BGP 节点状态

calicoctl 可以支持通过直接操作 etcd 或者对接 kubernetes apiserver 两种数据源，我这里使用 kubernetes 方式

具体的安装及配置方式请参考官网 Install calicoctl 与 Configure calicoctl

$ export CALICO_DATASTORE_TYPE=kubernetes
$ export CALICO_KUBECONFIG=/etc/kubernetes/admin.conf
$ calicoctl node status
Calico process is running.

IPv4 BGP status
+---------------+-------------------+-------+----------+-------------+
| PEER ADDRESS  |     PEER TYPE     | STATE |  SINCE   |    INFO     |
+---------------+-------------------+-------+----------+-------------+
| 10.64.144.101 | node-to-node mesh | up    | 18:11:48 | Established |
| 10.64.144.102 | node-to-node mesh | up    | 18:10:48 | Established |
| 10.64.144.103 | node-to-node mesh | up    | 18:08:10 | Established |
| 10.64.144.104 | node-to-node mesh | up    | 18:22:31 | Established |
| 10.64.144.105 | node-to-node mesh | up    | 18:22:31 | Established |
| 10.64.144.106 | node-to-node mesh | up    | 18:07:43 | Established |
+---------------+-------------------+-------+----------+-------------+

IPv6 BGP status
No IPv6 peers found.

确认查看集群状态

$ kubectl get pods -n kube-system
NAME                                       READY   STATUS    RESTARTS   AGE
calico-kube-controllers-7d4d547dd6-qr98t   1/1     Running   0          22s
calico-node-8d8bm                          1/1     Running   0          22s
calico-node-hlv2h                          1/1     Running   0          22s
calico-node-nbt4b                          1/1     Running   0          22s
calico-node-p4s45                          1/1     Running   0          22s
calico-node-srb88                          1/1     Running   0          22s
calico-node-vfpfv                          1/1     Running   0          22s
coredns-67c766df46-5d5pp                   1/1     Running   0          15m
coredns-67c766df46-kjd9f                   1/1     Running   0          15m
etcd-k8s-master                            1/1     Running   0          15m
kube-apiserver-k8s-master                  1/1     Running   0          14m
kube-controller-manager-k8s-master         1/1     Running   0          15m
kube-proxy-5tx57                           1/1     Running   0          14m
kube-proxy-6zvzv                           1/1     Running   0          14m
kube-proxy-hv8zt                           1/1     Running   0          14m
kube-proxy-rfsjl                           1/1     Running   0          14m
kube-proxy-tm7jz                           1/1     Running   0          15m
kube-proxy-kkssc                           1/1     Running   0          13m
kube-scheduler-k8s-master                  1/1     Running   0          14m
$ kubectl get nodes
NAME         STATUS   ROLES    AGE   VERSION
k8s-master   Ready    master   16m   v1.16.3
k8s-node01   Ready    <none>   14m   v1.16.3
k8s-node02   Ready    <none>   14m   v1.16.3
k8s-node03   Ready    <none>   14m   v1.16.3
k8s-node04   Ready    <none>   14m   v1.16.3
k8s-node05   Ready    <none>   15m   v1.16.3
k8s-node06   Ready    <none>   14m   v1.16.3

此时可以发现所有节点已经是 Ready 状态，且 coredns 也已经正常 Running

配置节点之间流量加密 (可选)

所有节点上操作

calico 支持通过 WireGuard 对节点之间的流量进行加密传输(仅支持 BGP 模式)

目前处于 preview 状态，不可用于生产环境

安装 WireGuard 可参考 WireGuard Installation

yum install epel-release https://www.elrepo.org/elrepo-release-7.el7.elrepo.noarch.rpm
yum install yum-plugin-elrepo
yum install kmod-wireguard wireguard-tools

加载 WireGuard 内核模块

$ modprobe wireguard
$ lsmod | grep wireguard
wireguard              86016  0
curve25519_x86_64      40960  1 wireguard
libchacha20poly1305    16384  1 wireguard
ip6_udp_tunnel         16384  1 wireguard
udp_tunnel             16384  1 wireguard
libblake2s             16384  1 wireguard
libcurve25519_generic    53248  2 curve25519_x86_64,wireguard

添加模块开机自动加载

$ cat > /etc/sysconfig/modules/wireguard.modules <<'EOF'
#!/bin/bash
/sbin/modinfo -F filename wireguard > /dev/null 2>&1
if [ $? -eq 0 ]; then
    /sbin/modprobe wireguard
fi
EOF
$ chmod +x wireguard.modules

修改配置开启 wireguard 功能

$ calicoctl patch felixconfiguration default --type='merge' -p '{"spec":{"wireguardEnabled":true}}'
Successfully patched 1 'FelixConfiguration' resource

查看节点状态

$ calicoctl get node k8s-master -oyaml
apiVersion: projectcalico.org/v3
kind: Node
....
status:
  wireguardPublicKey: 1OP5d3RVhBK7FE9tJ6l+eG38isdiy3LHzfqPzBSwI34=

测试

创建 pod 测试集群是否能正常工作

尝试创建名为 busybox 的 pod

由于 1.28 以上版本的 busybox 镜像，使用 nslookup 的时候有些 bug 导致不能解析域名，此处使用官方提供提供的 1.28 版本 busybox 的 pod 配置

$ kubectl apply -f https://raw.githubusercontent.com/kubernetes/website/master/content/en/examples/admin/dns/busybox.yaml
pod/busybox created

测试 coredns 能否正常工作

在 busybox pod 中测试

$ kubectl exec -it busybox -- nslookup kubernetes.default.svc.cluster.local
Server:    10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local

Name:      kubernetes.default.svc.cluster.local
Address 1: 10.96.0.1 kubernetes.default.svc.cluster.local

在节点中使用 dig 命令测试

$ dig kubernetes.default.svc.cluster.local @10.96.0.10
; <<>> DiG 9.11.4-P2-RedHat-9.11.4-9.P2.el7 <<>> kubernetes.default.svc.cluster.local @10.96.0.10
;; global options: +cmd
;; Got answer:
;; WARNING: .local is reserved for Multicast DNS
;; You are currently testing what happens when an mDNS query is leaked to DNS
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 56913
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;kubernetes.default.svc.cluster.local. IN A

;; ANSWER SECTION:
kubernetes.default.svc.cluster.local. 14 IN A   10.96.0.1

;; Query time: 1 msec
;; SERVER: 10.96.0.10#53(10.96.0.10)
;; WHEN: Fri Nov 22 12:21:58 CST 2019
;; MSG SIZE  rcvd: 117

安装 Ingress

配置文件参考官方 mandatory.yaml

不过官方是使用 Deployment 来部署的，我这里改成了 DaemonSet 方式，同时补上了 Service 的部分

完整配置如下

$ cat > ingress-nginx.yaml <<'EOF'
apiVersion: v1
kind: Namespace
metadata:
  name: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
---
kind: ConfigMap
apiVersion: v1
metadata:
  name: nginx-configuration
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
---
kind: ConfigMap
apiVersion: v1
metadata:
  name: tcp-services
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
---
kind: ConfigMap
apiVersion: v1
metadata:
  name: udp-services
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: nginx-ingress-serviceaccount
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
  name: nginx-ingress-clusterrole
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
rules:
  - apiGroups:
      - ""
    resources:
      - configmaps
      - endpoints
      - nodes
      - pods
      - secrets
    verbs:
      - list
      - watch
  - apiGroups:
      - ""
    resources:
      - nodes
    verbs:
      - get
  - apiGroups:
      - ""
    resources:
      - services
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - ""
    resources:
      - events
    verbs:
      - create
      - patch
  - apiGroups:
      - "extensions"
      - "networking.k8s.io"
    resources:
      - ingresses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - "extensions"
      - "networking.k8s.io"
    resources:
      - ingresses/status
    verbs:
      - update
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: Role
metadata:
  name: nginx-ingress-role
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
rules:
  - apiGroups:
      - ""
    resources:
      - configmaps
      - pods
      - secrets
      - namespaces
    verbs:
      - get
  - apiGroups:
      - ""
    resources:
      - configmaps
    resourceNames:
      # Defaults to "<election-id>-<ingress-class>"
      # Here: "<ingress-controller-leader>-<nginx>"
      # This has to be adapted if you change either parameter
      # when launching the nginx-ingress-controller.
      - "ingress-controller-leader-nginx"
    verbs:
      - get
      - update
  - apiGroups:
      - ""
    resources:
      - configmaps
    verbs:
      - create
  - apiGroups:
      - ""
    resources:
      - endpoints
    verbs:
      - get
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: RoleBinding
metadata:
  name: nginx-ingress-role-nisa-binding
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: nginx-ingress-role
subjects:
  - kind: ServiceAccount
    name: nginx-ingress-serviceaccount
    namespace: ingress-nginx
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: nginx-ingress-clusterrole-nisa-binding
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: nginx-ingress-clusterrole
subjects:
  - kind: ServiceAccount
    name: nginx-ingress-serviceaccount
    namespace: ingress-nginx
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: nginx-ingress-controller
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
spec:
  selector:
    matchLabels:
      app.kubernetes.io/name: ingress-nginx
      app.kubernetes.io/part-of: ingress-nginx
  template:
    metadata:
      labels:
        app.kubernetes.io/name: ingress-nginx
        app.kubernetes.io/part-of: ingress-nginx
      annotations:
        prometheus.io/port: "10254"
        prometheus.io/scrape: "true"
    spec:
      # wait up to five minutes for the drain of connections
      terminationGracePeriodSeconds: 300
      serviceAccountName: nginx-ingress-serviceaccount
      nodeSelector:
        kubernetes.io/os: linux
      containers:
        - name: nginx-ingress-controller
          image: quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.26.1
          args:
            - /nginx-ingress-controller
            - --configmap=$(POD_NAMESPACE)/nginx-configuration
            - --tcp-services-configmap=$(POD_NAMESPACE)/tcp-services
            - --udp-services-configmap=$(POD_NAMESPACE)/udp-services
            - --publish-service=$(POD_NAMESPACE)/ingress-nginx
            - --annotations-prefix=nginx.ingress.kubernetes.io
          securityContext:
            allowPrivilegeEscalation: true
            capabilities:
              drop:
                - ALL
              add:
                - NET_BIND_SERVICE
            # www-data -> 33
            runAsUser: 33
          env:
            - name: POD_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
          ports:
            - name: http
              containerPort: 80
            - name: https
              containerPort: 443
          livenessProbe:
            failureThreshold: 3
            httpGet:
              path: /healthz
              port: 10254
              scheme: HTTP
            initialDelaySeconds: 10
            periodSeconds: 10
            successThreshold: 1
            timeoutSeconds: 10
          readinessProbe:
            failureThreshold: 3
            httpGet:
              path: /healthz
              port: 10254
              scheme: HTTP
            periodSeconds: 10
            successThreshold: 1
            timeoutSeconds: 10
          lifecycle:
            preStop:
              exec:
                command:
                  - /wait-shutdown
---
apiVersion: v1
kind: Service
metadata:
  name: nginx-ingress-controller
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
spec:
  type: LoadBalancer
  externalTrafficPolicy: Local
  selector:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
  ports:
    - name: http
      port: 80
      protocol: TCP
      targetPort: 80
    - name: https
      port: 443
      protocol: TCP
      targetPort: 443
EOF

部署

$ kubectl apply -f ingress-nginx.yaml  # 执行部署
namespace/ingress-nginx created
configmap/nginx-configuration created
configmap/tcp-services created
configmap/udp-services created
serviceaccount/nginx-ingress-serviceaccount created
clusterrole.rbac.authorization.k8s.io/nginx-ingress-clusterrole created
role.rbac.authorization.k8s.io/nginx-ingress-role created
rolebinding.rbac.authorization.k8s.io/nginx-ingress-role-nisa-binding created
clusterrolebinding.rbac.authorization.k8s.io/nginx-ingress-clusterrole-nisa-binding created
daemonset.apps/nginx-ingress-controller created
service/nginx-ingress-controller created
$ kubectl get pods -n ingress-nginx  # 查看pod运行状态
NAME                             READY   STATUS    RESTARTS   AGE
nginx-ingress-controller-2hc8m   1/1     Running   0          4m36s
nginx-ingress-controller-69rfm   1/1     Running   0          4m36s
nginx-ingress-controller-ps7gt   1/1     Running   0          4m36s
nginx-ingress-controller-zfq56   1/1     Running   0          4m36s
$ kubectl get service -n ingress-nginx  # 查看service状态
NAME                       TYPE           CLUSTER-IP     EXTERNAL-IP   PORT(S)                      AGE
nginx-ingress-controller   LoadBalancer   10.96.76.163   <pending>     80:31832/TCP,443:30219/TCP   6m10s

此时发现 pod 已经正常运行了，但是 service 的 EXTERNAL-IP 字段却是 pending 状态

这是由于我们集群中还没有能处理 LoadBalancer 类型 service 的程序

在云环境中都会有个额外的组件 Cloud-Controller-Manager(CCM) 来对接云平台的负载均衡服务，如阿里云的 SLB，AWS 的 ALB 等

那么线下环境有没有办法实现类似 CCM 的功能呢，答案是 metallb

部署 Metallb

metallb 是一款为祼机 Kubernetes 环境提供标准路由协议的开源软负载均衡器，支持基于二层网络 ARP 或基于 BGP 方式进行地址广播

更详细的介绍请参考官方文档或Github

关于裸机下基于 Metallb 的负载均衡方案可参考 ingress-nginx 官方文档 A pure software solution: MetalLB

由于当前的物理环境中不支持 BGP，所以使用最简单的二层 ARP 方式

部署:

$ kubectl apply -f https://raw.githubusercontent.com/google/metallb/v0.8.3/manifests/metallb.yaml
namespace/metallb-system created
podsecuritypolicy.policy/speaker created
serviceaccount/controller created
serviceaccount/speaker created
clusterrole.rbac.authorization.k8s.io/metallb-system:controller created
clusterrole.rbac.authorization.k8s.io/metallb-system:speaker created
role.rbac.authorization.k8s.io/config-watcher created
clusterrolebinding.rbac.authorization.k8s.io/metallb-system:controller created
clusterrolebinding.rbac.authorization.k8s.io/metallb-system:speaker created
rolebinding.rbac.authorization.k8s.io/config-watcher created
daemonset.apps/speaker created
deployment.apps/controller created
$ kubectl get pods -n metallb-system
NAME                          READY   STATUS    RESTARTS   AGE
controller-65895b47d4-fbs7t   1/1     Running   0          3m21s
speaker-2skdk                 1/1     Running   0          3m21s
speaker-6mg76                 1/1     Running   0          3m21s
speaker-7rr8q                 1/1     Running   0          3m21s
speaker-dv2rh                 1/1     Running   0          3m21s
speaker-mwkqr                 1/1     Running   0          3m21s

创建配置文件

addresses 表示 LoadBalancer 可使用的 IP 池范围

$ cat > metallb-configmap.yaml <<EOF
apiVersion: v1
kind: ConfigMap
metadata:
  namespace: metallb-system
  name: config
data:
  config: |
    address-pools:
    - name: default
      protocol: layer2
      addresses:
      - 10.64.144.150-10.64.144.250
EOF
$ kubectl apply -f metallb-configmap.yaml
configmap/config created

而此时再去查看 ingree-nginx 的 service 可以发现已经 EXTERNAL-IP 字段已经能正常拿到 IP 了

$ kubectl get service -n ingress-nginx
NAME                       TYPE           CLUSTER-IP     EXTERNAL-IP     PORT(S)                      AGE
nginx-ingress-controller   LoadBalancer   10.96.76.163   10.64.144.150   80:31832/TCP,443:30219/TCP   50m

测试 ingress-nginx 及 metallb

前面已经创建了 ingress-nginx 及 metallb,但到目前为止也只是看到了集群中的状态，并不能说明它俩是真的可用

所以我们来创建一个简单的应用来测试下

$ cat > nginx-test.yaml <<EOF
---
apiVersion: v1
kind: Service
metadata:
  creationTimestamp: null
  name: nginx
  labels:
    run: nginx
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
    name: http
  selector:
    run: nginx
status:
  loadBalancer: {}
---
apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    run: nginx
  name: nginx
spec:
  replicas: 1
  selector:
    matchLabels:
      run: nginx
  template:
    metadata:
      creationTimestamp: null
      labels:
        run: nginx
    spec:
      containers:
      - image: nginx:alpine
        name: nginx
        ports:
        - containerPort: 80
---
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: nginx
  labels:
    run: nginx
spec:
  rules:
  - host: test.nginx.com
    http:
      paths:
      - path: /
        backend:
          serviceName: nginx
          servicePort: http
EOF
$ kubectl apply -f nginx-test.yaml
service/nginx created
deployment.apps/nginx created
ingress.networking.k8s.io/nginx created
$ curl -H 'Host: test.nginx.com' http://10.64.144.150 # 在局域网中其他机器测试访问
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
        width: 35em;
        margin: 0 auto;
        font-family: Tahoma, Verdana, Arial, sans-serif;
    }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>

由此 ingress-nginx 及负载均衡器 Metallb 已经部署完成

环境准备#

系统及软件版本#

主机列表#

网络规划#

系统初始化#

配置 hosts 同步#

设置主机名#

更新系统#

更新内核#

配置网卡驱动(可选)#

重启后验证内核版本#

禁用 SELinux#

禁用 swap#

禁用不需要的服务#

安装必要工具#

优化系统内核#

开启 ipvs 支持#

时间同步#

运行 docker 检测脚本#

重启系统#

安装 Docker#

安装#

修改配置文件#

启动并检查配置是否生效#

安装 kubernetes 相关工具#

添加阿里云 YUM 源#

查看支持的版本列表#

安装 kubeadm、kubectl、kubelet 工具#

添加 kubelet 开机自启动#

初始化集群#

生成 kubeadm 配置文件#

修改配置#

下载所需镜像(可选)#

初始化#

配置 kubeconfig#

加入 worker 节点到集群#

安装 CNI 网络插件#

下载 calico.yaml#

部署#

通过 calicoctl 查看 BGP 节点状态#

确认查看集群状态#

配置节点之间流量加密 (可选)#

测试#

创建 pod 测试集群是否能正常工作#

测试 coredns 能否正常工作#

安装 Ingress#

部署 Metallb#

测试 ingress-nginx 及 metallb#