基础环境
关闭防火墙 selinux
$ systemctl stop firewalld && systemctl disable firewalld
$ setenforce 0
打开forward
sysctl -w net.ipv4.ip_forward=1
<!–more–>
关闭swap
swapoff -a
再把/etc/fstab文件中带有swap的行删了,没有就无视
装这两工具如果没装的话
yum install -y ebtables socat
IPv4 iptables 链设置 CNI插件需要
sysctl net.bridge.bridge-nf-call-iptables=1
墙外安装
在国内是很难使用这种方式安装了,推荐查看离线安装的方案
装docker
yum install -y docker
systemctl enable docker && systemctl start docker
装kubeadm kubectl kubelet
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg
https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF
setenforce 0
yum install -y kubelet kubeadm kubectl
systemctl enable kubelet && systemctl start kubelet
关闭SElinux
setenforce 0
cat <<EOF > /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl –system
然后与离线安装启动master无异, kubeadm init
离线安装
福利,我已经把所有依赖的镜像,二进制文件,配置文件都打成了包,解决您所有依赖,花了很多时间整理这个,放在了阿里云市场上,希望大家给点小支持
赏我一杯咖啡
这包里面把大部分操作都写在简单的脚本里面了,在master节点执行 init-master.sh 在node节点执行init-node.sh 安装dashboard执行init-dashboard.sh。
然后就可以在node节点执行master输出出来的join命令了。包的最大价值在于没有任何依赖了,再也不用访问不了国外某网而头疼了。
安装kubelet服务,和kubeadm
下载bin文件
地址
把下载好的kubelet kubectl kubeadm 直接拷贝到/usr/bin下面
配置kubelet systemd服务
cat <<EOF > /etc/systemd/system/kubelet.service
[Unit]
Description=kubelet: The Kubernetes Node Agent
Documentation=http://kubernetes.io/docs/
[Service]
ExecStart=/usr/bin/kubelet
Restart=always
StartLimitInterval=0
RestartSec=10
[Install]
WantedBy=multi-user.target
EOF
cat <<EOF > /etc/systemd/system/kubelet.service.d/10-kubeadm.conf
[Service]
Environment="KUBELET_KUBECONFIG_ARGS=--bootstrap-kubeconfig=/etc/kubernetes/bootstrap-kubelet.conf --kubeconfig=/etc/kubernetes/kubelet.conf"
Environment="KUBELET_SYSTEM_PODS_ARGS=--pod-manifest-path=/etc/kubernetes/manifests --allow-privileged=true"
Environment="KUBELET_NETWORK_ARGS=--network-plugin=cni --cni-conf-dir=/etc/cni/net.d --cni-bin-dir=/opt/cni/bin"
Environment="KUBELET_DNS_ARGS=--cluster-dns=10.96.0.10 --cluster-domain=cluster.local"
Environment="KUBELET_AUTHZ_ARGS=--authorization-mode=Webhook --client-ca-file=/etc/kubernetes/pki/ca.crt"
Environment="KUBELET_CADVISOR_ARGS=--cadvisor-port=0"
Environment="KUBELET_CGROUP_ARGS=--cgroup-driver=cgroupfs"
Environment="KUBELET_CERTIFICATE_ARGS=--rotate-certificates=true --cert-dir=/var/lib/kubelet/pki"
ExecStart=
ExecStart=/usr/bin/kubelet $KUBELET_KUBECONFIG_ARGS $KUBELET_SYSTEM_PODS_ARGS $KUBELET_NETWORK_ARGS $KUBELET_DNS_ARGS $KUBELET_AUTHZ_ARGS $KUBELET_CADVISOR_ARGS $KUBELET_CGROUP_ARGS $KUBELET_CERTIFICATE_ARGS $KUBELET_EXTRA_ARGS
EOF
这里需要主意的是要看一下docker的cgroup driver与 –cgroup-driver要一致。 可以用 docker info |grep Cgroup 查看,有可能是systemd 或者 cgroupfs
增加主机名解析
为了防止无法解析主机名,修改/etc/hosts把主机名与ip的映射写上
启动master节点
这里得把google的一票镜像想办法弄下来
kubeadm init --pod-network-cidr=192.168.0.0/16 --kubernetes-version v1.8.0 --skip-preflight-checks
- –pod-network-cidr 参数安装calico网络时需要
- –kubernetes-version 不加的话会去请求公网查询版本信息
- –skip-preflight-checks 解决一个kubelet目录不空的小bug
看到这些输出时你便成功了:
To start using your cluster, you need to run (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:
http://kubernetes.io/docs/admin/addons/
You can now join any number of machines by running the following on each node
as root:
kubeadm join --token <token> <master-ip>:<master-port> --discovery-token-ca-cert-hash sha256:<hash>
照着执行:
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
安装calico网络
kubectl apply -f https://docs.projectcalico.org/v2.6/getting-started/kubernetes/installation/hosted/kubeadm/1.6/calico.yaml
join node节点
同样到node节点安装kubelet和kubeadm,和master节点操作一样,不再赘述。
然后执行master节点init输出的那个命令:
kubeadm join --token <token> <master-ip>:<master-port> --discovery-token-ca-cert-hash sha256:<hash>
执行完成后在master节点用kubectl验证节点是否健康
[root@dev-86-202 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
dev-86-202 NotReady master 17h v1.8.1
注意,master节点默认是不作为node的,也不推荐做node节点。 如果需要把master当node:
[root@dev-86-202 ~]# kubectl taint nodes --all node-role.kubernetes.io/master-
安装dashboard
安装dashboard不难,使用时还真有点绕,主要是RBAC, 先介绍个简单的
kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/master/src/deploy/alternative/kubernetes-dashboard.yaml
安装完之后, 使用nodeport方式访问
kubectl -n kube-system edit service kubernetes-dashboard
把type: ClusterIP 改成 type: NodePort 然后保存
$ kubectl -n kube-system get service kubernetes-dashboard
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes-dashboard 10.100.124.90 <nodes> 443:31707/TCP 21h
https://masterip:31707 就可以访问dashboard了, 然而 。。 还不能用。
创建一个 dashboard-admin.yaml
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
name: kubernetes-dashboard
labels:
k8s-app: kubernetes-dashboard
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: cluster-admin
subjects:
- kind: ServiceAccount
name: kubernetes-dashboard
namespace: kube-system
kubectl create -f dashboard-admin.yaml
然后在界面上直接点skip就可以了,不过你懂的,这很不安全。 真正安全的做法 请关注我进一步讨论:https://github.com/fanux
给节点加上角色
kubectl label node node1 kubernetes.io/role=node
常见问题
kubelet服务启动不了?
cgroup driver配置要相同
查看docker cgroup driver:
docker info|grep Cgroup
有systemd和cgroupfs两种,把kubelet service配置改成与docker一致
vim /etc/systemd/system/kubelet.service.d/10-kubeadm.conf
KUBELET_CGROUP_ARGS=–cgroup-driver=cgroupfs #这个配置与docker改成一致
节点not ready ?
建议安装calico网络,如果要把主节点当成node节点需要加个命令:
[root@dev-86-202 ~]# kubectl taint nodes --all node-role.kubernetes.io/master-
dashboard 访问不了?
如果是NodePort方式访问,那需要知道dashboard服务具体调度到哪个节点上去了。访问那个节点的ip而不是master的ip。
不行的话把https 改成http试试。
查看具体在哪个节点
kubectl get pod -n kube-system -o wide
拉取镜像失败?
可以把node节点与master节点的镜像都在每个节点load一下。
dashboard crash, dns起不来?
可以把node节点与master节点的镜像都在每个节点load一下。
192.168网段与calico网段冲突?
如果你恰好也是192.168网段,那么建议修改一下calico的网段
这样init
kubeadm init --pod-network-cidr=192.168.122.0/24 --kubernetes-version v1.8.1
修改calico.yaml
- name: FELIX_DEFAULTENDPOINTTOHOSTACTION
value: "ACCEPT"
# Configure the IP Pool from which Pod IPs will be chosen.
- name: CALICO_IPV4POOL_CIDR
value: "192.168.122.0/24"
- name: CALICO_IPV4POOL_IPIP
value: "always"
# Disable IPv6 on Kubernetes.
- name: FELIX_IPV6SUPPORT
value: "false"
dns 半天起不来?
dns镜像如果load成功了的话,可能是机器配置太低,起的会非常慢,有朋友 单核2G上15分钟没启动成功。 建议双核4G以上资源
如果还起不来请kubeadm reset重来一下,有客户是通过这种方式解决这个问题的.
kubelet unhealthy?
[kubelet-check] The HTTP call equal to 'curl -sSL http://localhost:10255/healthz/syncloop' failed with error: Get http://localhost:10255/healthz/syncloop: dial tcp 127.0.0.1:10255: getsockopt: connection refused.
[kubelet-check] It seems like the kubelet isn't running or healthy.
可能是manifast已经存在,删除即可:
[root@dev-86-205 kubeadm]# rm -rf /etc/kubernetes/manifests
时间超过24小时,节点加不进去?
[root@dev-86-208 test]# kubeadm token create
[kubeadm] WARNING: starting in 1.8, tokens expire after 24 hours by default (if you require a non-expiring token use --ttl 0)
887ac7.e82f0e13ad72c367
上面命令重新生成一下token,执行kubeadm join 时用上面的token替换一下,如果想永远不过期init时把ttl设置成0
–token-ttl duration
calico pod 中一个容器起不来,Calico node ‘xxx’ is already using the IPv4 address 192.168.152.65
rm -rf /var/etcd/
kubeadm reset
重装
卡在拉镜像的地方
关闭防火墙和selinux
$ systemctl stop firewalld && systemctl disable firewalld
$ setenforce 0
$ echo 'Environment="KUBELET_EXTRA_ARGS=--fail-swap-on=false"' > /etc/systemd/system/kubelet.service.d/90-local-extras.conf
$ systemctl daemon-reload
$ systemctl restart kubelet
Failed to get system container stats for “/system.slice/docker.service”
kubelet启动参数加:
--runtime-cgroups=/systemd/system.slice --kubelet-cgroups=/systemd/system.slice
节点无法加入
dns没起来就join,或者服务器时间没同步
使用配置文件指定外部etcd集群
config.yaml:
apiVersion: kubeadm.k8s.io/v1alpha1
kind: MasterConfiguration
etcd:
endpoints:
- http://10.1.245.94:2379
networking:
podSubnet: 192.168.0.0/16
kubernetesVersion: v1.8.1
etcd.yaml:
version: '2'
services:
etcd:
container_name: etcd_infra0
image: quay.io/coreos/etcd:v3.1.10
command: |
etcd --name infra0
--initial-advertise-peer-urls http://10.1.245.94:2380
--listen-peer-urls http://10.1.245.94:2380
--listen-client-urls http://10.1.245.94:2379,http://127.0.0.1:2379
--advertise-client-urls http://10.1.245.94:2379
--data-dir /etcd-data.etcd
--initial-cluster-token etcd-cluster-1
-initial-cluster infra0=http://10.1.245.94:2380
--initial-cluster-state new
volumes:
- /data/etcd-data.etcd:/etcd-data.etcd
network_mode: "host"
$ pip install docker-compose
$ docker-compose -f etcd.yaml up -d
$ kubeadm init --config config.yaml
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