这篇文章主要介绍“kubeadm下安装kubernetes1.12.1的方法”，在日常操作中，相信很多人在kubeadm下安装kubernetes1.12.1的方法问题上存在疑惑，小编查阅了各式资料，整理出简单好用的操作方法，希望对大家解答”kubeadm下安装kubernetes1.12.1的方法”的疑惑有所帮助！接下来，请跟着小编一起来学习吧！
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准备环境
服务器情况：
| IP | 系统版本 | 角色 | Hostname | | 10.20.13.24 | Centos7 64位 minimal | master | kuber24 |
| 10.20.13.25 | Centos7 64位 minimal | work | Kuber25 |
| 10.20.13.26 | Centos7 64位 minimal | work | Kuber26 |
| 10.20.13.27 | Centos7 64位 minimal | work | Kuber27 |
修改host
ansible 脚本,hostname = kuber[点分十进制最后一个数]：
---
- hosts: k8
remote_user: root
tasks:
- name: origin hostname
command: hostname
- name: server ip
shell: ip a
- hostname: name=kuber{{ ansible_default_ipv4.address.split('.')[-1] }}关闭firewall
linux 命令：
service firewalld stop
systemctl disable firewalld
ansible playbook
---
- hosts: k8
remote_user: root
tasks:
- name: stop firewalld
systemd: name=firewalld enabled=false state=stopped
- name: check firewalld status
shell: service firewalld status
关闭swap分区
linux 命令：
swappoff -a
sed -i 's/.*swap.*/#&/' /etc/fstab
ansible playbook
---
- hosts: k8
remote_user: root
tasks:
- name: close swap
shell: swapoff -a && sed -i 's/.*swap.*/#&/' /etc/fstab
ip转发参数
linux命令：
cat < /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
ansible playbook
---
- hosts: k8
remote_user: root
tasks:
- name: copy k8s ip configs
copy: src='/etc/sysctl.d/k8s.conf' dest='/etc/sysctl.d/k8s.conf'
- name: effect configs
shell: sysctl --system
此ansible-playbook需要先执行前面的linux命令，保证/etc/sysctl.d/k8s.conf的存在。
设置yum源
设置国内的阿里云 centos源。
linux 命令：
cat < /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
ansible playbook
---
- hosts: k8
remote_user: root
tasks:
- name: copy k8s ali repos
copy: src='/etc/yum.repos.d/kubernetes.repo' dest='/etc/yum.repos.d/kubernetes.repo'
此ansible-playbook需要先执行前面的linux命令，保证/etc/yum.repos.d/kubernetes.repo的存在。
安装必备工具
linux 命令：
yum install -y epel-release
yum install -y net-tools wget vim ntpdate
ansible playbook
---
- hosts: k8
remote_user: root
tasks:
- name: install epel repos
yum: pkg=epel-release state=latest
- name: install net tools
yum: pkg=net-tools state=latest
- name: install wget
yum: pkg=wget state=latest
- name: install vim
yum: pkg=vim state=latest
- name: install ntpdate
yum: pkg=ntpdate state=latest
安装docker
linux 命令：
yum install -y docker
systemctl enable docker && systemctl start docker
#设置系统服务，如果不设置后面 kubeadm init 的时候会有 warning
systemctl enable docker.service
ansible-playbook
---
- hosts: k8
remote_user: root
tasks:
- name: install docker
yum: pkg=docker state=latest
- name: start docker and start when login
systemd: name=docker enabled=true state=started
- name: set up docker system service
shell: systemctl enable docker.service
安装kubeadm kubelet kubectl kubernetes-cni
linux 命令：
yum install -y kubelet kubeadm kubectl kubernetes-cni
systemctl enable kubelet && systemctl start kubelet
ansible-playbook：
---
- hosts: k8
remote_user: root
tasks:
- name: install kubelet
yum: pkg=kubelet state=latest
- name: install kubeadm
yum: pkg=kubeadm state=latest
- name: install kubectl
yum: pkg=kubectl state=latest
- name: install kubernetes-cni
yum: pkg=kubernetes-cni state=latest
- name: start kubelet service
systemd: name=kubelet enabled=true state=started
完整的环境ansible-playbook
---
- hosts: k8
remote_user: root
vars:
# cluster hostname prefix
- HOST_PREFIX: kuber
# bridge ip config file path
- BRIDGE_CONF: ./k8s.conf
# ali yun repos config file path
- ALI_REPO_CONF: ./kubernetes.repo
tasks:
- name: origin hostname
command: hostname
- name: server ip
shell: ip a
- hostname: name={{HOST_PREFIX}}{{ ansible_default_ipv4.address.split('.')[-1] }}
- name: stop firewalld
systemd: name=firewalld enabled=false state=stopped
- name: close swap
shell: swapoff -a && sed -i 's/.*swap.*/#&/' /etc/fstab
- name: copy k8s ip configs
copy: src='{{ BRIDGE_CONF }}' dest='/etc/sysctl.d/k8s.conf'
- name: effect configs
shell: sysctl --system
- name: copy k8s ali repos
copy: src='{{ ALI_REPO_CONF }}' dest='/etc/yum.repos.d/kubernetes.repo'
- name: install epel repos
yum: pkg=epel-release state=latest
- name: install net tools
yum: pkg=net-tools state=latest
- name: install wget
yum: pkg=wget state=latest
- name: install vim
yum: pkg=vim state=latest
- name: install ntpdate
yum: pkg=ntpdate state=latest如果曾经安装过kubernetes，需要卸载相应的包，使用rpm -qa|grep kube*查找相关的包。然后使用rpm -e 包名。
例如我的环境：
rpm -e kubernetes-1.5.2-0.7.git269f928.el7.x86_64 kubernetes-node-1.5.2-0.7.git269f928.el7.x86_64 kubernetes-master-1.5.2-0.7.git269f928.el7.x86_64 kubernetes-client-1.5.2-0.7.git269f928.el7.x86_64
安装Master 节点
准备 kubernetes 镜像
因为国内没办法访问Google的镜像源，变通的方法是从其他镜像源下载后，修改tag。执行下面这个Shell脚本即可。
#!/bin/bash
images=(kube-proxy-amd64:v1.12.1 kube-scheduler-amd64:v1.12.1 kube-controller-manager-amd64:v1.12.1 kube-apiserver-amd64:v1.12.1
etcd-amd64:3.2.24 coreDNS:1.2.2 pause-amd64:3.1 kubernetes-dashboard-amd64:v1.10.0 k8s-dns-sidecar-amd64:1.14.13 k8s-dns-kube-dns-amd64:1.14.13
k8s-dns-dnsmasq-nanny-amd64:1.14.13 )
for imageName in ${images[@]} ; do
docker pull mirrorgooglecontainers/$imageName
if [[ $imageName =~ "amd64" ]]; then
docker tag mirrorgooglecontainers/$imageName "k8s.gcr.io/${imageName//-amd64/}"
else
docker tag mirrorgooglecontainers/$imageName k8s.gcr.io/$imageName
fi
# docker rmi mirrorgooglecontainers/$imageName
done脚本的主要工作是获取镜像，然后将镜像的tag改为k8s.gcr.io/$imageName。
由于mirrorgooglecontainers没有coredns:1.2.2版本，所以需要从hub.docker.com查找coredns的官方发布版本，https://hub.docker.com/r/coredns/coredns/。
拉取和改造coredns:1.2.2：
docker pull coredns/coredns:1.2.2
docker tag coredns/coredns:1.2.2 k8s.gcr.io/coredns:1.2.2
我怎么知道kurnernetes需要依赖哪些镜像？ 直接运行kubeadm init 可以查看，因为需要科学上网，所以会超时，并且提示无法下载的镜像和版本。 目前已知kubernetes1.2.1的版本依赖的镜像：
k8s.gcr.io/kube-apiserver:v1.12.1
k8s.gcr.io/kube-controller-manager:v1.12.1
k8s.gcr.io/kube-scheduler:v1.12.1
k8s.gcr.io/kube-proxy:v1.12.1
k8s.gcr.io/etcd:3.2.24
k8s.gcr.io/coredns:1.2.2
k8s.gcr.io/etcd:3.2.24
k8s.gcr.io/coredns:1.2.2
Master 节点初始化
服务器使用了两块网卡，需要指定apiserver-advertise-address。
kubeadm init --kubernetes-version=v1.12.1 --pod-network-cidr=10.1.0.0/16 --apiserver-advertise-address=10.20.13.24
参数说明：
kubernetes-version：安装的kubernetes版本
pod-network-cidr: Pod网络的IP范围
apiserver-advertise-address：建议的apiserver访问地址
执行日志：
[root@kuber24 kubeadm-install]# kubeadm init --kubernetes-version=v1.12.1 --pod-network-cidr=10.1.0.0/16 --apiserver-advertise-address=10.20.13.24
[init] using Kubernetes version: v1.12.1
[preflight] running pre-flight checks
[preflight/images] Pulling images required for setting up a Kubernetes cluster
[preflight/images] This might take a minute or two, depending on the speed of your internet connection
[preflight/images] You can also perform this action in beforehand using 'kubeadm config images pull'
[kubelet] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[preflight] Activating the kubelet service
[certificates] Generated ca certificate and key.
[certificates] Generated apiserver certificate and key.
[certificates] apiserver serving cert is signed for DNS names [kuber24 kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 10.20.13.24]
[certificates] Generated apiserver-kubelet-client certificate and key.
[certificates] Generated front-proxy-ca certificate and key.
[certificates] Generated front-proxy-client certificate and key.
[certificates] Generated etcd/ca certificate and key.
[certificates] Generated apiserver-etcd-client certificate and key.
[certificates] Generated etcd/server certificate and key.
[certificates] etcd/server serving cert is signed for DNS names [kuber24 localhost] and IPs [127.0.0.1 ::1]
[certificates] Generated etcd/peer certificate and key.
[certificates] etcd/peer serving cert is signed for DNS names [kuber24 localhost] and IPs [10.20.13.24 127.0.0.1 ::1]
[certificates] Generated etcd/healthcheck-client certificate and key.
[certificates] valid certificates and keys now exist in "/etc/kubernetes/pki"
[certificates] Generated sa key and public key.
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/admin.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/kubelet.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/controller-manager.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/scheduler.conf"
[controlplane] wrote Static Pod manifest for component kube-apiserver to "/etc/kubernetes/manifests/kube-apiserver.yaml"
[controlplane] wrote Static Pod manifest for component kube-controller-manager to "/etc/kubernetes/manifests/kube-controller-manager.yaml"
[controlplane] wrote Static Pod manifest for component kube-scheduler to "/etc/kubernetes/manifests/kube-scheduler.yaml"
[etcd] Wrote Static Pod manifest for a local etcd instance to "/etc/kubernetes/manifests/etcd.yaml"
[init] waiting for the kubelet to boot up the control plane as Static Pods from directory "/etc/kubernetes/manifests"
[init] this might take a minute or longer if the control plane images have to be pulled
[apiclient] All control plane components are healthy after 34.506899 seconds
[uploadconfig] storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.12" in namespace kube-system with the configuration for the kubelets in the cluster
[markmaster] Marking the node kuber24 as master by adding the label "node-role.kubernetes.io/master=''"
[markmaster] Marking the node kuber24 as master by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[patchnode] Uploading the CRI Socket information "/var/run/dockershim.sock" to the Node API object "kuber24" as an annotation
[bootstraptoken] using token: gnq0ex.j4wqxy6o89f7tl1a
[bootstraptoken] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstraptoken] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstraptoken] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstraptoken] creating the "cluster-info" ConfigMap in the "kube-public" namespace
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy
Your Kubernetes master 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/
You can now join any number of machines by running the following on each node
as root:
kubeadm join 10.20.13.24:6443 --token gnq0ex.j4wqxy6o89f7tl1a --discovery-token-ca-cert-hash sha256:c59abe1944573cd9568c45e8d29cec6c9201348d707633c04fbb3ccb7036f851
看到上述信息kubernetes Master 节点已经初始化成功。 初始化后的信息十分关键，建议保存起来
启发： 通过kubeadm的输出可以看出kubernetes的MASTER的核心安装步骤和配置文件的位置。
#配置kubectl
export KUBECONFIG=/etc/kubernetes/admin.conf
# 获取节点信息
kubectl get nodes
# 查看所有namespace的pods情况
kubectl get pods --all-namespaces
运行日志如下：
[root@kuber24 kubeadm-install]# export KUBECONFIG=/etc/kubernetes/admin.conf
[root@kuber24 kubeadm-install]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
kuber24 NotReady master 49m v1.12.1
[root@kuber24 kubeadm-install]# kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system coredns-576cbf47c7-75gcc 0/1 Pending 0 48m
kube-system coredns-576cbf47c7-v242w 0/1 Pending 0 48m
kube-system etcd-kuber24 1/1 Running 0 48m
kube-system kube-apiserver-kuber24 1/1 Running 0 48m
kube-system kube-controller-manager-kuber24 1/1 Running 0 48m
kube-system kube-proxy-nd875 1/1 Running 0 48m
kube-system kube-scheduler-kuber24 1/1 Running 0 48m
[root@kuber24 kubeadm-install]#
从上述结果可以看到，kubermetes的coredns还是处于Pending状态，需要配置网络。
Master 节点网络设置
修改系统设置，创建 flannel 网络。
sysctl net.bridge.bridge-nf-call-iptables=1
启动flannel（如果服务器有多块网卡，或者需要更改网络信息，请先看完本小结内容）
kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/v0.10.0/Documentation/kube-flannel.yml
flannel 默认会使用主机的第一张网卡，如果你有多张网卡，需要通过配置单独指定。修改/添加kube-flannel.yml 中的kube-flannel-ds(kind:DaemonSet):spec.template.spec.containers[0].args[3]部分：
containers:
- name: kube-flannel
image: quay.io/coreos/flannel:v0.10.0-amd64
command:
- /opt/bin/flanneld
args:
- --ip-masq
- --kube-subnet-mgr
- --iface=enp0s3 #指定内网网卡,网卡名根据实际情况填
需要修改flannel 的网络配置，可以修改ConfigMap的net-conf.json字段：
net-conf.json: |
{
"Network": "10.1.0.0/16", # 此处根据实际情况修改flannel的网络范围,需要与kubeadm配置的--pod-network-cidr参数保持一致
"Backend": {
"Type": "vxlan"
}
}如果flannel镜像下载出现问题，使用docker pull rancher/coreos-flannel:v0.10.0镜像，修改kube-flannel.yml的如下位置，来更新flannel pod使用的镜像：
initContainers:
- name: install-cni
image: rancher/coreos-flannel:v0.10.0 #第一处
command:
- cp
args:
- -f
- /etc/kube-flannel/cni-conf.json
- /etc/cni/net.d/10-flannel.conflist
volumeMounts:
- name: cni
mountPath: /etc/cni/net.d
- name: flannel-cfg
mountPath: /etc/kube-flannel/
containers:
- name: kube-flannel
image: rancher/coreos-flannel:v0.10.0 #第二处
command:
- /opt/bin/flanneld
args:
- --ip-masq
- --kube-subnet-mgr
- --iface=enp2s0f0
配置更新好后，创建flannel：
kubectl apply -f kube-flannel.yml
k8s kube-flannel启动输出：
[root@kuber24 kubeadm-install]# 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
flannel 网络添加过程中的问题
再次查看所有namespace下的pods状态：
kubectl get pods --all-namespaces
我的还是Pending状态，如下：
[root@kuber24 kubeadm-install]# kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system coredns-576cbf47c7-75gcc 0/1 Pending 0 132m
kube-system coredns-576cbf47c7-v242w 0/1 Pending 0 132m
kube-system etcd-kuber24 1/1 Running 2 132m
kube-system kube-apiserver-kuber24 1/1 Running 1 132m
kube-system kube-controller-manager-kuber24 1/1 Running 2 132m
kube-system kube-proxy-nd875 1/1 Running 2 132m
kube-system kube-scheduler-kuber24 1/1 Running 2 132m
[root@kuber24 kubeadm-install]#
查看flannel的DaemonSet资源情况：
kubectl get daemonset --all-namespaces
发现flannel的Desired 数量是0。
[root@kuber24 kubeadm-install]# kubectl get daemonset --all-namespaces
NAMESPACE NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE
kube-system kube-flannel-ds 0 0 0 0 0 beta.kubernetes.io/arch=amd64 53m
kube-system kube-proxy 1 1 1 1 1 133m
为什么Desired 数量是0呢？因为DaemonSet的运行是每个节点运行一个Pod，理论上应该有多少节点，Desired就是几。想到kubernetes中资源调度都是使用选择器Selector确定资源的，那么可能是Selector不是满足的。flannel的node selector是：
nodeSelector:
beta.kubernetes.io/arch: amd64
极有可能本节点定义中无beta.kubernetes.io/arch: amd64标签。
使用命令查看node的详细信息：
kubectl get nodes
kubectl describe node kuber24
结果输出如下：
[root@kuber24 kubeadm-install]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
kuber24 NotReady master 138m v1.12.1
[root@kuber24 kubeadm-install]# kubectl describe node kuber24
Name: kuber24
Roles: master
Labels: beta.kubernetes.io/arch=amd64
beta.kubernetes.io/os=linux
kubernetes.io/hostname=kuber24
node-role.kubernetes.io/master=
Annotations: kubeadm.alpha.kubernetes.io/cri-socket: /var/run/dockershim.sock
node.alpha.kubernetes.io/ttl: 0
volumes.kubernetes.io/controller-managed-attach-detach: true
CreationTimestamp: Thu, 18 Oct 2018 18:48:52 +0800
Taints: node-role.kubernetes.io/master:NoSchedule
node.kubernetes.io/not-ready:NoSchedule
Unschedulable: false
Conditions:
Type Status LastHeartbeatTime LastTransitionTime Reason Message
---- ------ ----------------- ------------------ ------ -------
OutOfDisk False Thu, 18 Oct 2018 21:07:09 +0800 Thu, 18 Oct 2018 18:48:48 +0800 KubeletHasSufficientDisk kubelet has sufficient disk space available
MemoryPressure False Thu, 18 Oct 2018 21:07:09 +0800 Thu, 18 Oct 2018 18:48:48 +0800 KubeletHasSufficientMemory kubelet has sufficient memory available
DiskPressure False Thu, 18 Oct 2018 21:07:09 +0800 Thu, 18 Oct 2018 18:48:48 +0800 KubeletHasNoDiskPressure kubelet has no disk pressure
PIDPressure False Thu, 18 Oct 2018 21:07:09 +0800 Thu, 18 Oct 2018 18:48:48 +0800 KubeletHasSufficientPID kubelet has sufficient PID available
Ready False Thu, 18 Oct 2018 21:07:09 +0800 Thu, 18 Oct 2018 18:48:48 +0800 KubeletNotReady runtime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:docker: network plugin is not ready: cni config uninitialized
Addresses:
InternalIP: 10.20.13.24
Hostname: kuber24
Capacity:
attachable-volumes-azure-disk: 16
cpu: 16
ephemeral-storage: 51175Mi
hugepages-1Gi: 0
hugepages-2Mi: 0
memory: 32775684Ki
pods: 110
Allocatable:
attachable-volumes-azure-disk: 16
cpu: 16
ephemeral-storage: 48294789041
hugepages-1Gi: 0
hugepages-2Mi: 0
memory: 32673284Ki
pods: 110
System Info:
Machine ID: f5d4a7c028db41a29816c49b10a07950
System UUID: 49434D53-0200-9029-2500-29902500A3D7
Boot ID: 8330549a-cfbf-49fa-a944-a4747cb90ad5
Kernel Version: 3.10.0-862.11.6.el7.x86_64
OS Image: CentOS Linux 7 (Core)
Operating System: linux
Architecture: amd64
Container Runtime Version: docker://1.13.1
Kubelet Version: v1.12.1
Kube-Proxy Version: v1.12.1
PodCIDR: 10.1.0.0/24
Non-terminated Pods: (5 in total)
Namespace Name CPU Requests CPU Limits Memory Requests Memory Limits
--------- ---- ------------ ---------- --------------- -------------
kube-system etcd-kuber24 0 (0%) 0 (0%) 0 (0%) 0 (0%)
kube-system kube-apiserver-kuber24 250m (1%) 0 (0%) 0 (0%) 0 (0%)
kube-system kube-controller-manager-kuber24 200m (1%) 0 (0%) 0 (0%) 0 (0%)
kube-system kube-proxy-nd875 0 (0%) 0 (0%) 0 (0%) 0 (0%)
kube-system kube-scheduler-kuber24 100m (0%) 0 (0%) 0 (0%) 0 (0%)
Allocated resources:
(Total limits may be over 100 percent, i.e., overcommitted.)
Resource Requests Limits
-------- -------- ------
cpu 550m (3%) 0 (0%)
memory 0 (0%) 0 (0%)
attachable-volumes-azure-disk 0 0
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Warning ContainerGCFailed 16m (x7 over 22m) kubelet, kuber24 rpc error: code = Unknown desc = Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
Normal Starting 15m kube-proxy, kuber24 Starting kube-proxy.
发现此Node的labels中包含此label。那还可能是什么原因呢？
一番搜索后，发现：https://serverfault.com/questions/933428/kubernetes-flannel-daemonset-not-starting-clean-ubuntu-16-and-18
原因是：创建flannel pod的配置文件中，daemonset的tolerations限制的过于严格，导致flannel pod不能被正常调度，通过将tolerations限制放宽，使得flannel pod可以正常调度。关于toleration的更多细节参考：kubernetes toleration说明
通过查看上述node的详细描述信息，发现node有两个taint，分别是：
node-role.kubernetes.io/master:NoSchedule
node.kubernetes.io/not-ready:NoSchedule
而此时kube-flannel的toleration是：
tolerations:
- key: node-role.kubernetes.io/master
operator: Exists
effect: NoSchedule
这个tolerations仅能容忍node-role.kubernetes.io/master:NoSchedule，不能容忍node.kubernetes.io/not-ready:NoSchedule所以flannel pod不能被正常的调度。
使用
kubectl patch daemonset kube-flannel-ds \
--namespace=kube-system \
--patch='{"spec":{"template":{"spec":{"tolerations":[{"key": "node-role.kubernetes.io/master", "operator": "Exists", "effect": "NoSchedule"},{"effect":"NoSchedule","operator":"Exists"}]}}}}'上述方法添加了一个无key的toleration，表示该toleration 容忍任意key。
解决问题。
再次获取pods信息，如下：
[root@kuber24 ~]# kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system coredns-576cbf47c7-75gcc 1/1 Running 0 15h
kube-system coredns-576cbf47c7-v242w 1/1 Running 0 15h
kube-system etcd-kuber24 1/1 Running 2 15h
kube-system kube-apiserver-kuber24 1/1 Running 1 15h
kube-system kube-controller-manager-kuber24 1/1 Running 2 15h
kube-system kube-flannel-ds-gwcj5 1/1 Running 0 12h
kube-system kube-proxy-nd875 1/1 Running 2 15h
kube-system kube-scheduler-kuber24 1/1 Running 2 15h
安装Node节点
安装node节点前，需要先执行环境准备章节的所有步骤。
使用之前的ansible playbook 即可，注意playbook的hosts配置。
准备docker镜像
#!/bin/bash
images=(kube-proxy-amd64:v1.12.1 pause-amd64:3.1)
for imageName in ${images[@]} ; do
docker pull mirrorgooglecontainers/$imageName
if [[ $imageName =~ "amd64" ]]; then
docker tag mirrorgooglecontainers/$imageName "k8s.gcr.io/${imageName//-amd64/}"
else
docker tag mirrorgooglecontainers/$imageName k8s.gcr.io/$imageName
fi
# docker rmi mirrorgooglecontainers/$imageName
done加入集群
依据kubeadm init的初始化后的结果提示，运行命令：
kubeadm join 10.20.13.24:6443 --token gnq0ex.j4wqxy6o89f7tl1a --discovery-token-ca-cert-hash sha256:c59abe1944573cd9568c45e8d29cec6c9201348d707633c04fbb3ccb7036f851
⚠️注意：
此处依据前面的kubeadm init的输出提示来操作。
master 节点默认已经加入到集群了，不用做此操作。
查看节点状态，可能会为：
[root@kuber24 playbooks]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
kuber24 Ready master 23h v1.12.1
kuber25 NotReady 14s v1.12.1
kuber26 NotReady 14s v1.12.1
kuber27 NotReady 13s v1.12.1
等待一段时间后（此时在创建flannel网络），会自动变为READY：
[root@kuber24 playbooks]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
kuber24 Ready master 23h v1.12.1
kuber25 Ready 3m41s v1.12.1
kuber26 Ready 3m41s v1.12.1
kuber27 Ready 3m40s v1.12.1
查看此时的集群PODS情况：
[root@kuber24 playbooks]# kubectl get pods --all-namespaces -o wide
NAMESPACE NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE
kube-system coredns-576cbf47c7-75gcc 1/1 Running 0 23h 10.1.0.3 kuber24
kube-system coredns-576cbf47c7-v242w 1/1 Running 0 23h 10.1.0.2 kuber24
kube-system etcd-kuber24 1/1 Running 2 23h 10.20.13.24 kuber24
kube-system kube-apiserver-kuber24 1/1 Running 1 23h 10.20.13.24 kuber24
kube-system kube-controller-manager-kuber24 1/1 Running 2 23h 10.20.13.24 kuber24
kube-system kube-flannel-ds-6hqc4 1/1 Running 0 5m36s 10.20.13.25 kuber25
kube-system kube-flannel-ds-bs4b7 1/1 Running 0 5m35s 10.20.13.27 kuber27
kube-system kube-flannel-ds-gwcj5 1/1 Running 0 20h 10.20.13.24 kuber24
kube-system kube-flannel-ds-tmsbc 1/1 Running 0 5m36s 10.20.13.26 kuber26
kube-system kube-proxy-fqm89 1/1 Running 0 5m35s 10.20.13.27 kuber27
kube-system kube-proxy-nd875 1/1 Running 2 23h 10.20.13.24 kuber24
kube-system kube-proxy-qsf9z 1/1 Running 0 5m36s 10.20.13.25 kuber25
kube-system kube-proxy-ww8x7 1/1 Running 0 5m36s 10.20.13.26 kuber26
kube-system kube-scheduler-kuber24 1/1 Running 2 23h 10.20.13.24 kuber24
问题总结
flannel pod desired=0
参考本文档的：flannel 网络添加过程中的问题 小结。
时间同步问题
错误信息：
[discovery] Failed to request cluster info, will try again: [Get https://192.168.0.101:6443/api/v1/namespaces/kube-public/configmaps/cluster-info: x509: certificate has expired or is not yet valid]
解决：
ntpdate ntp1.aliyun.com
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