Centos7 kubeadmin安装kubernetes1.1
2018-09-14 本文已影响734人
bdslinux
环境
关闭防火墙，selinux,基于主机名访问（dns或者dns）,同步时间（时间不一致，集群运行异常，如不能启动）,关闭swap分区
#hosts
10.1.101.202 inspur2.ops.bds.bj1 inspur2
10.1.101.203 inspur2.ops.bds.bj1 inspur3
系统初始化
# 关掉 selinux
setenforce 0
sed -i "s/^SELINUX=enforcing/SELINUX=disabled/g" /etc/sysconfig/selinux
# 关掉防火墙
systemctl stop firewalld
systemctl disable firewalld
#关闭swap
swapoff -a
#开启转发的参数，根据实际报错情况开启，一般有如下三项
cat <<EOF > /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
EOF
#加载内核配置
sysctl --system /etc/sysctl.d/k8s.conf
# 加载ipvs相关内核模块
# 如果重新开机，需要重新加载
modprobe ip_vs
modprobe ip_vs_rr
modprobe ip_vs_wrr
modprobe ip_vs_sh
modprobe nf_conntrack_ipv4
lsmod | grep ip_vs
master 配置
docker镜像
cd /etc/yum.repos.d/
wget https://mirrors.tuna.tsinghua.edu.cn/docker-ce/linux/centos/docker-ce.repo
wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
配置docker镜像加速
mkdir -p /etc/docker
vim /etc/docker/daemon.json
{"registry-mirrors": ["http://08b61f14.m.daocloud.io"]}
配置拉取gcr.io镜像
1 通过配置代理来下载k8s镜像
vim /usr/lib/systemd/system/docker.service
Environment="HTTPS_PROXY=http://www.ik8s.io:10080"
Environment="HTTP_PROXY=http://www.ik8s.io:10080"
Environment="NO_PROXY=127.0.0.0/8,172.20.0.0/16"
#保存退出后，执行
systemctl daemon-reload
systemctl enable docker
systemctl start docker
2 技术大牛github拉取镜像
vim pullimages.sh
#!/bin/bash
images=(kube-proxy-amd64:v1.11.2 kube-scheduler-amd64:v1.11.2 kube-controller-manager-amd64:v1.11.2 kube-apiserver-amd64:v1.11.2
etcd-amd64:3.2.18 coredns:1.1.3 pause:3.1 )
for imageName in ${images[@]} ; do
docker pull anjia0532/google-containers.$imageName
docker tag anjia0532/google-containers.$imageName k8s.gcr.io/$imageName
docker rmi anjia0532/google-containers.$imageName
done
k8s repo镜像
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
install kubeadm
yum -y install kubeadm kubelet kubectl
kubeadm config
vim /etc/systemd/system/kubelet.service.d/10-kubeadm.conf
Environment="KUBELET_CGROUP_ARGS=--cgroup-driver=cgroupfs"
systemctl enable kubelet.service
systemctl start kubelet
kubelet error log
注意，此时启动会出现报错，查看/var/log/messages的日志
tail -f /var/log/messages
如果出现如下的报错
failed to load Kubelet config file /var/lib/kubelet/config.yaml, error failed to read kubelet config file "/var/lib/kubelet/config.yaml", error: open /var/lib/kubelet/config.yaml: no such file or directory
忽略以上的报错，设置为开机自启动即可，因为此时的配置还没初始化完成，所以此时不能启动kubelet,等后续kubeadm启动成功后再查看
swap 分区注意
注意，需要关闭swap分区，或者在如下的配置文件里修改，表示添加而且的
启动选项
vim /etc/sysconfig/kubelet
KUBELET_EXTRA_ARGS="--fail-swap-on=false"
建议执行 swapoff -a 关闭swap分区，不用配置上述选项
k8s 初始化
master节点上用kubeadm命令来初始化集群 这个时候会拉取gcr.io镜像时间会比较长
kubeadm init --kubernetes-version=v1.11.1 --pod-network-cidr=10.244.0.0/16 --service-cidr=10.96.0.0/12
因为我们这里选择flannel作为Pod网络插件，所以需要制定--pod-netwrok-cidr=10.244.0.0/16
初始化过程会生成相关的证书，kubeconfig文件，bootstraptoken等等
后面是使用kubeadm join往集群中添加节点时用到的命令，这个命令后面的
--token和--discovery-token-ca-cert-hash一定要保留备份好，后面添加节点的时候会使用到，如果丢失也可以通过命里找回，但是比较麻烦。
配置使用kubectl访问集群
mkdir -p $HOME/.kube sudo cp -i /etc/kubernetes/admin.conf
$HOME/.kube/config sudo chown $(id -u):$(id -g)
$HOME/.kube/config
查看master k8s状态
#查看组件的健康状态
[root@inspur2 ~]# kubectl get cs
NAME STATUS MESSAGE ERROR
scheduler Healthy ok
controller-manager Healthy ok
etcd-0 Healthy {"health": "true"}
#查看集群中node
[root@inspur2 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
inspur2.ops.haodf.bj1 Ready master 16h v1.11.3
#查看nodespace名称空间
[root@inspur2 ~]# kubectl get ns
NAME STATUS AGE
default Active 16h
kube-public Active 16h
kube-system Active 16h
install Pod network
master节点安装下载
[root@inspur2 ~]# wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
[root@inspur2 ~]# kubectl apply -f kube-flannel.yml
clusterrole.rbac.authorization.k8s.io "flannel" created
clusterrolebinding.rbac.authorization.k8s.io "flannel" created
serviceaccount "flannel" created
configmap "kube-flannel-cfg" created
daemonset.extensions "kube-flannel-ds" created
多网卡配置
如果你的节点有多个网卡的话,需要在kube-flannel.yml 中使用 --iface 参数指定集群主机内网网卡的名称，否则可能会出现dns无法解析。 flanneld 启动参数加上 --iface=
args:
- --ip-masq
- --kube-subnet-mgr
- --iface=eth0
查看gcr.io镜像和fannel镜像
[root@inspur2 ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
k8s.gcr.io/kube-proxy-amd64 v1.11.1 d5c25579d0ff 8 weeks ago 97.8MB
k8s.gcr.io/kube-scheduler-amd64 v1.11.1 272b3a60cd68 8 weeks ago 56.8MB
k8s.gcr.io/kube-controller-manager-amd64 v1.11.1 52096ee87d0e 8 weeks ago 155MB
k8s.gcr.io/kube-apiserver-amd64 v1.11.1 816332bd9d11 8 weeks ago 187MB
k8s.gcr.io/coredns 1.1.3 b3b94275d97c 3 months ago 45.6MB
k8s.gcr.io/etcd-amd64 3.2.18 b8df3b177be2 5 months ago 219MB
quay.io/coreos/flannel v0.10.0-amd64 f0fad859c909 7 months ago 44.6MB
k8s.gcr.io/pause 3.1 da86e6ba6ca1 8 months ago 742kB
[root@inspur2 ~]# kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-78fcdf6894-m9kwr 1/1 Running 1 16h
coredns-78fcdf6894-tgjn6 1/1 Running 1 16h
etcd-inspur2.ops.haodf.bj1 1/1 Running 1 16h
kube-apiserver-inspur2.ops.haodf.bj1 1/1 Running 1 16h
kube-controller-manager-inspur2.ops.haodf.bj1 1/1 Running 1 16h
kube-flannel-ds-amd64-d8vxk 1/1 Running 5 16h
kube-proxy-24gvj 1/1 Running 1 16h
kube-scheduler-inspur2.ops.haodf.bj1 1/1 Running 1 16h
如果集群遇到问题，使用下面命令来重置
kubeadm reset
ifconfig cni0 down && ip link delete cni0
ifconfig flannel.1 down && ip link delete flannel.1
rm -rf /var/lib/cni/
node节点操作
yum仓库准备好后，在以下的两个节点上执行安装如下包，
yum -y install kubeadm kubelet kubectl docker-ce
系统初始化
# 关掉 selinux
setenforce 0
sed -i "s/^SELINUX=enforcing/SELINUX=disabled/g" /etc/sysconfig/selinux
# 关掉防火墙
systemctl stop firewalld
systemctl disable firewalld
#关闭swap
swapoff -a
#开启转发的参数，根据实际报错情况开启，一般有如下三项
cat <<EOF > /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
EOF
#加载内核配置
sysctl --system /etc/sysctl.d/k8s.conf
start docker
# 设置开启自启动
systemctl enable docker.service
systemctl enable kubelet.service
#
systemctl start docker
把配置文件从master拷贝到node节点 保持配置一致
scp /usr/lib/systemd/system/docker.service 10.1.101.203:/usr/lib/systemd/system/docker.service
scp /etc/systemd/system/kubelet.service.d/10-kubeadm.conf 10.1.101.203:/etc/systemd/system/kubelet.service.d/10-kubeadm.conf
scp /etc/sysconfig/kubelet 10.1.101.203:/etc/sysconfig/
node节点加入master
kubeadm join 10.1.101.202:6443 --token gt8abw.jaaivoggg2imqnld --discovery-token-ca-cert-hash sha256:2220de69ce7084d672dd1f282246a76c4a5bb04661b2ada23a3014e203eb14b3
node执行上面命令成功后，提示信息如下
......
This node has joined the cluster:
* Certificate signing request was sent to master and a response
was received.
* The Kubelet was informed of the new secure connection details.
Run 'kubectl get nodes' on the master to see this node join the cluster.
看到上面信息代表发布成功
node 节点容器信息
[root@inspur3 ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
k8s.gcr.io/kube-proxy-amd64 v1.11.1 d5c25579d0ff 8 weeks ago 97.8MB
quay.io/coreos/flannel v0.10.0-amd64 f0fad859c909 7 months ago 44.6MB
k8s.gcr.io/pause 3.1 da86e6ba6ca1 8 months ago 742kB
验证集群
[root@inspur2 ~]# kubectl get pod -n kube-system -o wide
NAME READY STATUS RESTARTS AGE IP NODE
coredns-78fcdf6894-m9kwr 1/1 Running 1 16h 10.244.0.5 inspur2.ops.haodf.bj1
coredns-78fcdf6894-tgjn6 1/1 Running 1 16h 10.244.0.4 inspur2.ops.haodf.bj1
etcd-inspur2.ops.haodf.bj1 1/1 Running 1 16h 10.1.101.202 inspur2.ops.haodf.bj1
kube-apiserver-inspur2.ops.haodf.bj1 1/1 Running 1 16h 10.1.101.202 inspur2.ops.haodf.bj1
kube-controller-manager-inspur2.ops.haodf.bj1 1/1 Running 1 16h 10.1.101.202 inspur2.ops.haodf.bj1
kube-flannel-ds-amd64-d8vxk 1/1 Running 7 16h 10.1.101.202 inspur2.ops.haodf.bj1
kube-flannel-ds-amd64-lh2jf 1/1 Running 0 5m 10.1.101.203 inspur3.ops.haodf.bj1
kube-proxy-24gvj 1/1 Running 1 16h 10.1.101.202 inspur2.ops.haodf.bj1
kube-proxy-n29ch 1/1 Running 0 5m 10.1.101.203 inspur3.ops.haodf.bj1
kube-scheduler-inspur2.ops.haodf.bj1 1/1 Running 1 16h 10.1.101.202 inspur2.ops.haodf.bj1
以上信息有这个 inspur3.ops.haodf.bj1从节点的信息，flannel和proxy都有两个pod
[root@inspur2 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
inspur2.ops.bds.bj1 Ready master 16h v1.11.3
inspur3.ops.bds.bj1 Ready <none> 4m v1.11.3
忘记初始master节点时的node节点加入集群命令
kubeadm token create $token --print-join-command --ttl=0
k8s通过kubeadm搭建集群成功
