[原]使用kubeadm部署kubernetes（一）

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在公众号  木子李的菜田

输入关键词：   k8s

有系列安装文档

此文档是之前做笔记在两台机上进行的实践，kubernetes处于不断开发阶段

不能保证每个步骤都能准确到同步开发进度，所以如果安装部署过程中有问题请尽量google

本文章分为两部分：

[原]使用kubeadm部署kubernetes（一）

[原]部署kubernetes dashboard（二）

按照下面步骤能得到什么？

1.两台主机：一台为server ，另外一台为node节点

2.在node节点上安装部署dashboard插件 并以kubernetes dashboard的方式呈现

3.解决遇到的问题

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OS: CentOS 7.5

kubernetes :Kubernetes v1.14.1

network model: flannel

###

【在两台机器上都要做的步骤如下】

 

0.修改添加node的hosts文件和停止防火墙

systemctl stop firewalld && systemctl disable firewalld

1.免密双方登录

2.时间同步   （可参见https://www.cnblogs.com/horizonli/p/9539436.html）

3.关闭selinux

# Set SELinux in permissive mode (effectively disabling it)

setenforce
sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config

4.打开数据包转发

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

sysctl --system

　　

5.加载网络筛选器

modprobe br_netfilter
lsmod | grep br_netfilter

6.检查桥工具包（如果没有需要重新安装）

rpm -qa |grep bridge-utils

7关闭swap

swapoff -a

vim /etc/fstab
在这行前面添加#
#/dev/mapper/centos-swap swap                    swap    defaults        0 0

　　

8（可选项，可以不选择执行，只作为参考，则使用的是iptables模式）.kube-proxy开启ipvs的前置条件

cat > /etc/sysconfig/modules/ipvs.modules <<EOF
#!/bin/bash
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack_ipv4
EOF
chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules && lsmod | grep -e ip_vs -e nf_conntrack_ipv4

【注意】上面脚本创建了的/etc/sysconfig/modules/ipvs.modules文件，保证在节点重启后能自动加载所需模块。 使用lsmod | grep -e ip_vs -e nf_conntrack_ipv4命令查看是否已经正确加载所需的内核模块。
接下来还需要确保各个节点上已经安装了ipset软件包yum install ipset。 为了便于查看ipvs的代理规则，最好安装一下管理工具ipvsadm yum install ipvsadm  如果以上前提条件如果不满足，
则即使kube-proxy的配置开启了ipvs模式，也会退回到iptables模式

　　

 

9.安装docker

Kubernetes从1.6开始使用CRI(Container Runtime Interface)容器运行时接口。默认的容器运行时仍然是Docker，使用的是kubelet中内置dockershim CRI实现

安装docker的yum源

yum install -y yum-utils device-mapper-persistent-data lvm2
sudo yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
sudo yum makecache fast

　或者使用　

yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager \
--add-repo \
https://download.docker.com/linux/centos/docker-ce.repo

【注意】　　

在后面kubeadm进行init的时候会报个类似这样的错误：

[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 18.09.3. Latest validated version: 18.06

通过查看k8s更改记录可以查到支持的docker版本号

https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.13.md

指定特定的docker版本号进行安装

• kubeadm now properly recognizes Docker 18.09.0 and newer, but still treats 18.06 as the default supported version.

如果之前有错误的docker需要先卸载： yum remove docker-ce* -y

列出可安装的docker版本

yum list docker-ce.x86_64  --showduplicates |sort -r
docker-ce.x86_64            3:18.09.0-3.el7                    docker-ce-stable
docker-ce.x86_64            18.06.3.ce-3.el7                   docker-ce-stable
docker-ce.x86_64            18.06.2.ce-3.el7                   docker-ce-stable
docker-ce.x86_64            18.06.1.ce-3.el7                   docker-ce-stable
docker-ce.x86_64            18.06.0.ce-3.el7                   docker-ce-stable

yum install docker-ce-18.06.3.ce-3.el7 -y

systemctl start docker && systemctl enable docker  

 

编辑或者创建/etc/docker/daemon.json  更改设置镜像库

[root@k8s-master flannel]# cat <<EOF  >/etc/docker/daemon.json
{
"registry-mirrors": ["https://72idtxd8.mirror.aliyuncs.com"]
}
EOF

systemctl reset-failed docker.service && systemctl restart docker.service

 

10安装[kubernetes]

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

能kexue上网的用下面这个

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
exclude=kube*
EOF

sudo yum makecache fast

yum install -y kubelet kubeadm kubectl　

官网对三个工具的介绍

kubeadm: the command to bootstrap the cluster.
kubelet: the component that runs on all of the machines in your cluster and does things like starting pods and containers.
kubectl: the command line util to talk to your cluster.

11 【只在master机器上执行】检查cgroup driver：

docker info | grep -i cgroup
Cgroup Driver: cgroupfs

如果不是cgroupfs 就用下面的命令改变：

sed -i 's/cgroup-driver=systemd/cgroup-driver=cgroupfs/g' /etc/systemd/system/kubelet.service.d/10-kubeadm.conf
systemctl daemon-reload

systemctl restart kubelet    ---》这句不执行会报错如下：

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　　

需要在成功启动初始化cluster的时候才能执行成功  所以需要先执行 kubeadm --init

%%%%%  下面是官方文档参考

When using Docker, kubeadm will automatically detect the cgroup driver for the kubelet and set it in the /var/lib/kubelet/kubeadm-flags.env file during runtime.
If you are using a different CRI, you have to modify the file /etc/default/kubelet with your cgroup-driver value, like so:

KUBELET_EXTRA_ARGS=--cgroup-driver=<value>
This file will be used by kubeadm init and kubeadm join to source extra user defined arguments for the kubelet.
Please mind, that you only have to do that if the cgroup driver of your CRI is not cgroupfs, because that is the default value in the kubelet already.
Restarting the kubelet is required:

systemctl daemon-reload
systemctl restart kubelet

12【这步在每个node上（包括master）都要进行操作】

刚才安装的是k8s软件，现在来处理k8s需要使用的镜像【可能在kubelet init的时候会遇到如下的错误】：

　　Failed to pull image "quay.io/coreos/flannel:v0.11.0-amd64" 等等

为了能解决这些问题，可以提前处理好镜像问题，使用kubeadm config images list 查看需要处理的基础镜像问题，

之所以为基础镜像是因为在kubelet init的时候就需要用到的镜像，后面还会有其他插件安装时候需要的镜像，当遇到

问题时再看看是什么镜像需要存在。

[root@k8s-master ~]# kubeadm config images list
k8s.gcr.io/kube-apiserver:v1.13.4
k8s.gcr.io/kube-controller-manager:v1.13.4
k8s.gcr.io/kube-scheduler:v1.13.4
k8s.gcr.io/kube-proxy:v1.13.4
k8s.gcr.io/pause:3.1
k8s.gcr.io/etcd:3.2.24
k8s.gcr.io/coredns:1.2.6　　

根据上面查出来的镜像名称，我写了个脚本来处理：

编辑拉取脚本：vim pull_image.sh
#!/bin/bash
#### 基础镜像 #####
images=(
kube-apiserver:v1.14.1
kube-controller-manager:v1.14.1
kube-scheduler:v1.14.1
kube-proxy:v1.14.1
pause:3.1
etcd:3.3.10
coredns:1.3.1
kubernetes-dashboard-amd64:v1.10.1
)
for imageName in ${images[@]};do
        docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/$imageName
        docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/$imageName k8s.gcr.io/$imageName
done

### 插件镜像 network: flannel image  ###
docker pull quay-mirror.qiniu.com/coreos/flannel:v0.11.0-amd64
docker tag quay-mirror.qiniu.com/coreos/flannel:v0.11.0-amd64  quay.io/coreos/flannel:v0.11.0-amd64

### 运行时插件镜像pause image ###
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1 k8s.gcr.io/pause:3.1

chmod a+x  pull_image.sh
./pull_image.sh
docker images

13【这步骤在master机器上执行】

　

 ~]# kubelet --version
Kubernetes v1.14.1　　

　初始化kubernetes master 机器：

kubeadm init --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=192.168.0.166 --kubernetes-version=v1.14.1  > kube_init.log

10.244.0.0/16  是使用flannel网络要设置的ip网络地址（官网介绍一定要使用这个）

【官网介绍】
For flannel to work correctly, you must pass --pod-network-cidr=10.244.0.0/16 to kubeadm init.
kubeadm init --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=10.50.10.10 --kubernetes-version=v1.13.4

192.168.0.166  为maser的主机ip地址

v1.14.1  是上面查出来的kubernetes 版本号

下面是我的操作记录：仅供参考：

　

[root@rancher ~]# kubeadm init --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=192.168.0.166 --kubernetes-version=v1.14.1
[init] Using Kubernetes version: v1.14.1
[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 Service-Kubelet]: kubelet service is not enabled, please run 'systemctl enable kubelet.service'
[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 [rancher kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.0.166]
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "etcd/ca" certificate and key
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [rancher localhost] and IPs [192.168.0.166 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [rancher localhost] and IPs [192.168.0.166 127.0.0.1 ::1]
[certs] Generating "front-proxy-ca" certificate and key
[certs] Generating "front-proxy-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 15.505486 seconds
[upload-config] storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.14" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --experimental-upload-certs
[mark-control-plane] Marking the node rancher as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node rancher as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: dije5w.ipijm49d8c9isxie
[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 192.168.0.166:6443 --token dije5w.ipijm49d8c9isxie \
    --discovery-token-ca-cert-hash sha256:c1aaaafc79d85141e60a73c43562e6b06cb8d9cdc24cc0a649c8d6e0f24c5f42

　　

14【在master上执行下面的操作】

以下完整步骤内容请在公众号：  木子李的菜田  输入： k8s 

为了能再node上正常操作kubelet，需要将master上的admin配置文件保存到每个node节点上

。。。。。　　

【在node上执行下面操作】

。。。。。

　　下面是非常很重要的一步！！！！

。。。。。。

【注意注意】如果在第一次kubeadm init的时候失败了，需要重新kubeadm 进行重新初始化，需要做下面的操作：

　

。。。。。。

检查kubernetes是否安装正确：

[root@master ~]# kubectl get pods --namespace=kube-system
NAME                             READY   STATUS    RESTARTS   AGE
coredns-86c58d9df4-srtht         0/1     Pending   0          3h
coredns-86c58d9df4-tl7ww         0/1     Pending   0          3h
etcd-master                      1/1     Running   0          179m
kube-apiserver-master            1/1     Running   0          179m
kube-controller-manager-master   1/1     Running   0          3h
kube-proxy-2sdmn                 1/1     Running   1          3h
kube-proxy-ln5tk                 1/1     Running   1          173m
kube-scheduler-master            1/1     Running   0          3h

　

发现很多都还不正确，这个时候先别急，继续第15和16步

　15 【只在master上进行操作】配置CNI-----这步跟网络息息相关

vim /etc/systemd/system/kubelet.service.d/10-kubeadm.conf
添加下面的内容
。。。。。。

　　

16安装flannel

#]kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/a70459be0084506e4ec919aa1c114638878db11b/Documentation/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-amd64 created
daemonset.extensions/kube-flannel-ds-arm64 created
daemonset.extensions/kube-flannel-ds-arm created
daemonset.extensions/kube-flannel-ds-ppc64le created
daemonset.extensions/kube-flannel-ds-s390x created

　　

　17最后在master和node上检查：

全部是Running 才算是真正的正确部署

[root@master ~]# kubectl get pods --namespace=kube-system
NAME                             READY   STATUS    RESTARTS   AGE
coredns-86c58d9df4-srtht         1/1     Running   0          3h16m
coredns-86c58d9df4-tl7ww         1/1     Running   0          3h16m
etcd-master                      1/1     Running   1          3h15m
kube-apiserver-master            1/1     Running   1          3h15m
kube-controller-manager-master   1/1     Running   1          3h16m
kube-flannel-ds-amd64-7mntm      1/1     Running   0          12m
kube-flannel-ds-amd64-bxzdn      1/1     Running   0          12m
kube-proxy-2sdmn                 1/1     Running   1          3h16m
kube-proxy-ln5tk                 1/1     Running   1          3h9m
kube-scheduler-master            1/1     Running   1          3h16m

　End

文章中有些地方的坑已经通过相关步骤填了，如果还遇到其他问题 请google一下或者使用

使用describe 查看原因   特别是要注意这个原因是在master还是在node节点上。