kubernetes部署集群
- 集群部署
- 获取镜像
- 安装docker[集群]
- 阿里仓库下载[集群]
- 集群部署[集群]
- 集群环境配置[集群]
- 关闭系统Swap[集群]
- 安装Kubeadm包[集群]
- 配置启动kubelet[集群]
- 配置master节点[master]
- 配置使用网络插件[master]
- node加入集群[node]
- 后续检查[master]
- 测试集群
集群部署
kubeadm部署官方文档
kubeadm部署k8s高可用集群的官方文档
主节点CPU核数必须是 ≥2核且内存要求必须≥2G，否则k8s无法启动
| 主机名 | 地址 | 角色 | 配置 |
|---|---|---|---|
| kub-k8s-master | 192.168.96.10 | 主节点 | 2核4G |
| kub-k8s-node1 | 192.168.96.20 | 工作节点 | 1核2G |
| kub-k8s-node2 | 192.168.96.30 | 工作节点 | 1核2G |
获取镜像
谷歌镜像[由于国内网络原因，无法下载，后续将采用阿里云镜像代替]
docker pull k8s.gcr.io/kube-apiserver:v1.22.0
docker pull k8s.gcr.io/kube-proxy:v1.22.0
docker pull k8s.gcr.io/kube-controller-manager:v1.22.0
docker pull k8s.gcr.io/kube-scheduler:v1.22.0
docker pull k8s.gcr.io/etcd:3.5.0-0
docker pull k8s.gcr.io/pause:3.5
docker pull k8s.gcr.io/coredns/coredns:v1.8.4
特别说明
所有机器都必须有镜像
每次部署都会有版本更新，具体版本要求，运行初始化过程失败会有版本提示
kubeadm的版本和镜像的版本必须是对应的
安装docker[集群]
过程请查看docker安装部分
阿里仓库下载[集群]
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.22.0
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.22.0
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.22.0
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.22.0
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:v1.8.4
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.5.0-0
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.5
# 下载完了之后需要将aliyun下载下来的所有镜像打成k8s.gcr.io/kube-controller-manager:v1.22.0这样的tag
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.22.0 k8s.gcr.io/kube-controller-manager:v1.22.0
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.22.0 k8s.gcr.io/kube-proxy:v1.22.0
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.22.0 k8s.gcr.io/kube-apiserver:v1.22.0
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.22.0 k8s.gcr.io/kube-scheduler:v1.22.0
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:v1.8.4 k8s.gcr.io/coredns/coredns:v1.8.4
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.5.0-0 k8s.gcr.io/etcd:3.5.0-0
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.5 k8s.gcr.io/pause:3.5
# 可以清理掉aliyun的镜像标签
docker rmi -f `docker images --format {{.Repository}}:{{.Tag}} | grep aliyun`
集群部署[集群]
cat >> /etc/hosts <<EOF
192.168.188.185 kub-k8s-master
192.168.188.186 kub-k8s-node1
192.168.188.187 kub-k8s-node2
EOF
制作本地解析，修改主机名。相互解析
集群环境配置[集群]
1.关闭防火墙：
# systemctl disable firewalld --now
2.禁用SELinux：
# setenforce 0
3.编辑文件/etc/selinux/config，将SELINUX修改为disabled，如下：
# sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/sysconfig/selinux
SELINUX=disabled
4.时间同步
# timedatectl set-timezone Asia/Shanghai
# yum install -y ntpdate
# ntpdate ntp.aliyun.com
5.配置静态ip
关闭系统Swap[集群]
Kubernetes 1.8开始要求关闭系统的Swap，如果不关闭，默认配置下kubelet将无法启动。
- 方法一: 通过kubelet的启动参数–fail-swap-on=false更改这个限制。
- 方法二: 关闭系统的Swap。
1.关闭swap分区
# swapoff -a
修改/etc/fstab文件，注释掉SWAP的自动挂载，使用free -m确认swap已经关闭。
2.注释掉swap分区：
# sed -i 's/.*swap.*/#&/' /etc/fstab
# free -m
total used free shared buff/cache available
Mem: 3935 144 3415 8 375 3518
Swap: 0 0 0
安装Kubeadm包[集群]
配置源
# cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
所有节点：
1.安装依赖包及常用软件包
# yum install -y conntrack ntpdate ntp ipvsadm ipset jq iptables curl sysstat libseccomp wget vim net-tools git iproute lrzsz bash-completion tree bridge-utils unzip bind-utils gcc
2.安装对应版本
# yum install -y kubelet-1.22.0-0.x86_64 kubeadm-1.22.0-0.x86_64 kubectl-1.22.0-0.x86_64
3.加载ipvs相关内核模块
# cat <<EOF > /etc/modules-load.d/ipvs.conf
ip_vs
ip_vs_lc
ip_vs_wlc
ip_vs_rr
ip_vs_wrr
ip_vs_lblc
ip_vs_lblcr
ip_vs_dh
ip_vs_sh
ip_vs_nq
ip_vs_sed
ip_vs_ftp
ip_vs_sh
nf_conntrack_ipv4
ip_tables
ip_set
xt_set
ipt_set
ipt_rpfilter
ipt_REJECT
ipip
EOF
4.配置：
配置转发相关参数，否则可能会出错
# cat <<EOF > /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-iptables=1
net.bridge.bridge-nf-call-ip6tables=1
net.ipv4.ip_forward=1
net.ipv4.tcp_tw_recycle=0
vm.swappiness=0
vm.overcommit_memory=1
vm.panic_on_oom=0
fs.inotify.max_user_instances=8192
fs.inotify.max_user_watches=1048576
fs.file-max=52706963
fs.nr_open=52706963
net.ipv6.conf.all.disable_ipv6=1
net.netfilter.nf_conntrack_max=2310720
EOF
5.使配置生效
# sysctl --system
6.如果net.bridge.bridge-nf-call-iptables报错，加载br_netfilter模块
# modprobe br_netfilter
# modprobe ip_conntrack
# sysctl -p /etc/sysctl.d/k8s.conf
7.查看是否加载成功
# lsmod | grep ip_vs
配置启动kubelet[集群]
1.配置kubelet使用pause镜像
获取docker的cgroups
# DOCKER_CGROUPS=$(docker info | grep 'Cgroup' | cut -d' ' -f4)
# echo $DOCKER_CGROUPS
=================================
配置变量：
[root@k8s-master ~]# DOCKER_CGROUPS=`docker info |grep 'Cgroup' | awk ' NR==1 {print $3}'`
[root@k8s-master ~]# echo $DOCKER_CGROUPS
cgroupfs
systemd
2.配置kubelet的cgroups
# cat >/etc/sysconfig/kubelet<<EOF
KUBELET_EXTRA_ARGS="--cgroup-driver=$DOCKER_CGROUPS --pod-infra-container-image=k8s.gcr.io/pause:3.5"
EOF
启动
# systemctl daemon-reload
# systemctl enable kubelet && systemctl restart kubelet
在这里使用 # systemctl status kubelet，你会发现报错误信息；
10月 11 00:26:43 node1 systemd[1]: kubelet.service: main process exited, code=exited, status=255/n/a
10月 11 00:26:43 node1 systemd[1]: Unit kubelet.service entered failed state.
10月 11 00:26:43 node1 systemd[1]: kubelet.service failed.
运行 # journalctl -xefu kubelet 命令查看systemd日志才发现，真正的错误是：
unable to load client CA file /etc/kubernetes/pki/ca.crt: open /etc/kubernetes/pki/ca.crt: no such file or directory
#这个错误在运行kubeadm init 生成CA证书后会被自动解决，此处可先忽略。
#简单地说就是在kubeadm init 之前kubelet会不断重启。
配置master节点[master]
运行初始化过程如下：
[root@kub-k8s-master]# kubeadm init --kubernetes-version=v1.22.0 --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=192.168.96.10
注：
apiserver-advertise-address=192.168.96.10 ---master的ip地址。
--kubernetes-version=v1.22.0 --更具具体版本进行修改
如果报错会有版本提示，那就是有更新新版本了
[init] Using Kubernetes version: v1.22.0
[preflight] Running pre-flight checks
[WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 18.03.0-ce. Latest validated version: 18.09
[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 [kub-k8s-master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.96.10]
[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 [kub-k8s-master localhost] and IPs [192.168.96.10 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [kub-k8s-master localhost] and IPs [192.168.96.10 127.0.0.1 ::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 24.575209 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 kub-k8s-master as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node kub-k8s-master as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: 93erio.hbn2ti6z50he0lqs
[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 192.168.96.10:6443 --token 93erio.hbn2ti6z50he0lqs \
--discovery-token-ca-cert-hash sha256:3bc60f06a19bd09f38f3e05e5cff4299011b7110ca3281796668f4edb29a56d9 #需要记住
上面记录了完成的初始化输出的内容，根据输出的内容基本上可以看出手动初始化安装一个Kubernetes集群所需要的关键步骤。
其中有以下关键内容：
[kubelet] 生成kubelet的配置文件”/var/lib/kubelet/config.yaml”
[certificates]生成相关的各种证书
[kubeconfig]生成相关的kubeconfig文件
[bootstraptoken]生成token记录下来，后边使用kubeadm join往集群中添加节点时会用到
配置使用kubectl
如下操作在master节点操作
[root@kub-k8s-master ~]# rm -rf $HOME/.kube
[root@kub-k8s-master ~]# mkdir -p $HOME/.kube
[root@kub-k8s-master ~]# cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@kub-k8s-master ~]# chown $(id -u):$(id -g) $HOME/.kube/config
查看node节点
[root@k8s-master ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master NotReady master 2m41s v1.22.0
配置使用网络插件[master]
# 版本差异 https://projectcalico.docs.tigera.io/archive/v3.22/getting-started/kubernetes/requirements
#> 部署calico网络插件
curl -L https://docs.projectcalico.org/v3.22/manifests/calico.yaml -O
kubectl apply -f calico.yaml
# kubectl get pod -A
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system calico-kube-controllers-6d9cdcd744-8jt5g 1/1 Running 0 6m50s
kube-system calico-node-rkz4s 1/1 Running 0 6m50s
kube-system coredns-74ff55c5b-bcfzg 1/1 Running 0 52m
kube-system coredns-74ff55c5b-qxl6z 1/1 Running 0 52m
kube-system etcd-kub-k8s-master 1/1 Running 0 53m
kube-system kube-apiserver-kub-k8s-master 1/1 Running 0 53m
kube-system kube-controller-manager-kub-k8s-master 1/1 Running 0 53m
kube-system kube-proxy-gfhkf 1/1 Running 0 52m
kube-system kube-scheduler-kub-k8s-master 1/1 Running 0 53m
node加入集群[node]
配置node节点加入集群：
如果报错开启ip转发：
# sysctl -w net.ipv4.ip_forward=1
在所有node节点操作，此命令为初始化master成功后返回的结果
# kubeadm join 192.168.96.10:6443 --token 93erio.hbn2ti6z50he0lqs \
--discovery-token-ca-cert-hash sha256:3bc60f06a19bd09f38f3e05e5cff4299011b7110ca3281796668f4edb29a56d9
后续检查[master]
各种检测：
1.查看pods:
[root@kub-k8s-master ~]# kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-5644d7b6d9-sm8hs 1/1 Running 0 39m
coredns-5644d7b6d9-vddll 1/1 Running 0 39m
etcd-kub-k8s-master 1/1 Running 0 37m
kube-apiserver-kub-k8s-master 1/1 Running 0 38m
kube-controller-manager-kub-k8s-master 1/1 Running 0 38m
kube-flannel-ds-amd64-9wgd8 1/1 Running 0 38m
kube-flannel-ds-amd64-lffc8 1/1 Running 0 2m11s
kube-flannel-ds-amd64-m8kk2 1/1 Running 0 2m2s
kube-proxy-dwq9l 1/1 Running 0 2m2s
kube-proxy-l77lz 1/1 Running 0 2m11s
kube-proxy-sgphs 1/1 Running 0 39m
kube-scheduler-kub-k8s-master 1/1 Running 0 37m
2.查看节点：
[root@kub-k8s-master ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
kub-k8s-master Ready master 43m v1.22.0
kub-k8s-node1 Ready <none> 6m46s v1.22.0
kub-k8s-node2 Ready <none> 6m37s v1.22.0
到此集群配置完成
测试集群
kubectl create deployment nginx --image=nginx #创建一个pod
名字 镜像
kubectl expose deployment nginx --port=80 --type=NodePort #对外暴露端口
kubectl get pod,svc #查看pod和详细信息
访问地址：http://nodeip:port
http://node ip:30449
systemctl start kubelet #启动k8s
kubectl get pods #查看pod
