Centos7 RKE部署高可用k8s集群
一、RKE介绍
1、介绍：RKE是经过CNCF认证的Kubernetes发行版,并且全部组件完全在Docker容器内运行
Rancher Server只能在使用RKE或K3s安装的Kubernetes集群中运行
2、节点环境准备
firewall-cmd --permanent --add-port=22/tcp firewall-cmd --permanent --add-port=80/tcp firewall-cmd --permanent --add-port=443/tcp firewall-cmd --permanent --add-port=30000-32767/tcp firewall-cmd --permanent --add-port=30000-32767/udp firewall-cmd --reload
2、同步节点时间
yum install ntpdate -y
ntpdate time.windows.com
3、安装docker
任何运行Rancher Server的节点上都需要安装Docker
sudo yum install -y yum-utils device-mapper-persistent-data lvm2 sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo sudo yum install docker-ce-18.09.3-3.el7
4、安装kubectl
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=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
sudo yum install kubectl
5、安装RKE
Rancher Kubernetes Engine用于构建Kubernetes集群的CLI
下载地址： https://github.com/rancher/rke/releases/tag/v1.1.3
mv rke_linux-amd64 rke chmod +x rke mv rke /usr/local/bin rke
6、安装Helm
Kubernetes的软件包管理工具
下载地址：https://github.com/helm/helm
tar -zxvf helm-v3.3.1-linux-amd64.tar.gz cd linux-amd64 mv helm /usr/local/bin chown -R admin:admin /usr/local/bin/helm helm version
7、配置ssh免密连接
用户加入docker用户组，让其可以执行docker命令
sudo usermod -aG docker admin
切换成admin用户，在执行rke up命令的主机上执行创建ssh公私钥 并把公钥分发到各个节点上
ssh-keygen -t rsa ssh-copy-id 192.168.112.120 ssh-copy-id 192.168.112.121
8、配置操作系统参数支持k8s集群 (所有节点上都要执行)
sudo swapoff -a sudo vi /etc/sysctl.conf net.ipv4.ip_forward = 1 net.bridge.bridge-nf-call-ip6tables = 1 net.bridge.bridge-nf-call-iptables = 1 sudo sysctl -p
9、使用rke创建集群初始化配置文件
rke config --name cluster.yml
RKE使用一个名为cluster.yml确定如何在集群中的节点上部署Kubernetes
# If you intened to deploy Kubernetes in an air-gapped environment, # please consult the documentation on how to configure custom RKE images. nodes: - address: "192.168.30.110" port: "22" internal_address: "" role: [controlplane,etcd,worker] hostname_override: "node1" user: admin docker_socket: /var/run/docker.sock ssh_key: "" ssh_key_path: ~/.ssh/id_rsa ssh_cert: "" ssh_cert_path: "" labels: {} taints: [] - address: "192.168.30.129" port: "22" internal_address: "" role: [controlplane,etcd,worker] hostname_override: "node2" user: admin docker_socket: /var/run/docker.sock ssh_key: "" ssh_key_path: ~/.ssh/id_rsa ssh_cert: "" ssh_cert_path: "" labels: {} taints: [] - address: "192.168.30.133" port: "22" internal_address: "" role: [controlplane,etcd,worker] hostname_override: "node3" user: admin docker_socket: /var/run/docker.sock ssh_key: "" ssh_key_path: ~/.ssh/id_rsa ssh_cert: "" ssh_cert_path: "" labels: {} taints: [] services: etcd: image: "" extra_args: {} extra_binds: [] extra_env: [] external_urls: [] ca_cert: "" cert: "" key: "" path: "" uid: 0 gid: 0 snapshot: null retention: "" creation: "" backup_config: null kube-api: image: "" extra_args: {} extra_binds: [] extra_env: [] service_cluster_ip_range: 10.43.0.0/16 service_node_port_range: "" pod_security_policy: false always_pull_images: false secrets_encryption_config: null audit_log: null admission_configuration: null event_rate_limit: null kube-controller: image: "" extra_args: {} extra_binds: [] extra_env: [] cluster_cidr: 10.42.0.0/16 service_cluster_ip_range: 10.43.0.0/16 scheduler: image: "" extra_args: {} extra_binds: [] extra_env: [] kubelet: image: "" extra_args: {} extra_binds: [] extra_env: [] cluster_domain: cluster.local infra_container_image: "" cluster_dns_server: 10.43.0.10 fail_swap_on: false generate_serving_certificate: false kubeproxy: image: "" extra_args: {} extra_binds: [] extra_env: [] network: plugin: flannel options: {} mtu: 0 node_selector: {} update_strategy: null authentication: strategy: x509 sans: [] webhook: null addons: "" addons_include: [] system_images: etcd: rancher/coreos-etcd:v3.4.3-rancher1 alpine: rancher/rke-tools:v0.1.58 nginx_proxy: rancher/rke-tools:v0.1.58 cert_downloader: rancher/rke-tools:v0.1.58 kubernetes_services_sidecar: rancher/rke-tools:v0.1.58 kubedns: rancher/k8s-dns-kube-dns:1.15.2 dnsmasq: rancher/k8s-dns-dnsmasq-nanny:1.15.2 kubedns_sidecar: rancher/k8s-dns-sidecar:1.15.2 kubedns_autoscaler: rancher/cluster-proportional-autoscaler:1.7.1 coredns: rancher/coredns-coredns:1.6.9 coredns_autoscaler: rancher/cluster-proportional-autoscaler:1.7.1 nodelocal: rancher/k8s-dns-node-cache:1.15.7 kubernetes: rancher/hyperkube:v1.18.3-rancher2 flannel: rancher/coreos-flannel:v0.12.0 flannel_cni: rancher/flannel-cni:v0.3.0-rancher6 calico_node: rancher/calico-node:v3.13.4 calico_cni: rancher/calico-cni:v3.13.4 calico_controllers: rancher/calico-kube-controllers:v3.13.4 calico_ctl: rancher/calico-ctl:v3.13.4 calico_flexvol: rancher/calico-pod2daemon-flexvol:v3.13.4 canal_node: rancher/calico-node:v3.13.4 canal_cni: rancher/calico-cni:v3.13.4 canal_flannel: rancher/coreos-flannel:v0.12.0 canal_flexvol: rancher/calico-pod2daemon-flexvol:v3.13.4 weave_node: weaveworks/weave-kube:2.6.4 weave_cni: weaveworks/weave-npc:2.6.4 pod_infra_container: rancher/pause:3.1 ingress: rancher/nginx-ingress-controller:nginx-0.32.0-rancher1 ingress_backend: rancher/nginx-ingress-controller-defaultbackend:1.5-rancher1 metrics_server: rancher/metrics-server:v0.3.6 windows_pod_infra_container: rancher/kubelet-pause:v0.1.4 ssh_key_path: ~/.ssh/id_rsa ssh_cert_path: "" ssh_agent_auth: false authorization: mode: rbac options: {} ignore_docker_version: null kubernetes_version: "" private_registries: [] ingress: provider: "" options: {} node_selector: {} extra_args: {} dns_policy: "" extra_envs: [] extra_volumes: [] extra_volume_mounts: [] update_strategy: null cluster_name: "" cloud_provider: name: "" prefix_path: "" addon_job_timeout: 0 bastion_host: address: "" port: "" user: "" ssh_key: "" ssh_key_path: "" ssh_cert: "" ssh_cert_path: "" monitoring: provider: "" options: {} node_selector: {} update_strategy: null replicas: null restore: restore: false snapshot_name: "" dns: null cluster.yaml
10、部署
rke up
11、设置环境变量
export KUBECONFIG=/home/admin/kube_config_cluster.yml mkdir ~/.kube cp kube_config_cluster.yml ~/.kube/config
通过RKE安装k8s集群成功,启动的时候有些节点启动的比较慢。需要稍微等待一段时间.
可以先找一台网络好一点的，pull全部镜像，再保存到本地，cp到所有主机
docker save -o images.tgz `docker images|awk 'NR>1 {print $1":"$2}'`
二、RKE的环境清理
1、rancher-node-1,2,3中分别执行以下命令
mkdir rancher cat > rancher/clear.sh << EOF df -h|grep kubelet |awk -F % '{print $2}'|xargs umount rm /var/lib/kubelet/* -rf rm /etc/kubernetes/* -rf rm /var/lib/rancher/* -rf rm /var/lib/etcd/* -rf rm /var/lib/cni/* -rf rm -rf /var/run/calico iptables -F && iptables -t nat -F ip link del flannel.1 docker ps -a|awk '{print $1}'|xargs docker rm -f docker volume ls|awk '{print $2}'|xargs docker volume rm rm -rf /var/etcd/ rm -rf /run/kubernetes/ docker rm -fv $(docker ps -aq) docker volume rm $(docker volume ls) rm -rf /etc/cni rm -rf /opt/cni systemctl restart docker EOF sh rancher/clear.sh 清理脚本
2、清理残留目录结束。如果还有问题可能需要卸载所有节点上的docker
首先查看Docker版本 # yum list installed | grep docker docker-ce.x86_64 18.05.0.ce-3.el7.centos @docker-ce-edge 执行卸载 # yum -y remove docker-ce.x86_64 删除存储目录 # rm -rf /etc/docker # rm -rf /run/docker # rm -rf /var/lib/dockershim # rm -rf /var/lib/docker 如果发现删除不掉，需要先 umount，如 # umount /var/lib/docker/devicemapper 卸载docker
rke up --config=./rancher-cluster.yml rke启动执行是幂等操作的 有时候需要多次执行才能成功
3、rke多次安装和卸载k8s集群问题
启动的时候提示ectd的集群健康检查失败
清空节点上所有k8s的相关目录。卸载和删除docker所有相关目录。重新安装docker
最后在执行rke启动命令
三、扩容节点，缩容节点
1、添加节点
修改cluster.yal 将需要添加的节点配置，然后运行
more cluster.yml nodes: - address: 172.20.101.103 user: ptmind role: [controlplane,worker,etcd] - address: 172.20.101.104 user: ptmind role: [controlplane,worker,etcd] - address: 172.20.101.105 user: ptmind role: [controlplane,worker,etcd] - address: 172.20.101.106 user: ptmind role: [worker] labels: {traefik: traefik-outer}
2、执行添加节点操作
rke up --update-only
3、rke 删除节点
修改cluster.yal 将需要删除的节点配置删除，然后运行
more cluster.yml nodes: - address: 172.20.101.103 user: ptmind role: [controlplane,worker,etcd] - address: 172.20.101.104 user: ptmind role: [controlplane,worker,etcd] - address: 172.20.101.105 user: ptmind role: [controlplane,worker,etcd] 删除# - address: 172.20.101.106 删除# user: ptmind 删除# role: [worker] 删除# labels: {traefik: traefik-outer}
4、执行删除节点操作
rke up --update-only
问题：当node节点处于NotReady状态下，对节点不可做操作，比如做了删除节点操作，会报错，删除不了节点。
解决办法：
1、手动删除节点上的组件。
2、通过命令移除节点的角色
kubectl label node prod-129 node-role.kubernetes.io/controlplane-
问题：k8s 集群的节点处于 SchedulingDisabled
解决方法：
kubectl patch node NodeName -p "{\"spec\":{\"unschedulable\":false}}"
或者：
设置不可调度 kubectl cordon node07-ingress 取消节点不可调度 kubectl uncordon node07-ingress 驱逐节点的pod kubectl drain --ignore-daemonsets --delete-local-data node07-ingress 删除节点 kubectl delete node node07-ingress
