Kubernetes集群搭建:基于Kubeadm

Kubernetes集群搭建:基于Kubeadm

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一,环境准备

* K8S版本为15.1

* Docker版本最高支持18.06.1

二,Docker环境构建及替换

1,清除原Docker环境,原版本为最新版

yum remove docker \
docker-client \
docker-client-latest \
docker-common \
docker-latest \
docker-latest-logrotate \
docker-logrotate \
docker-selinux \
docker-engine-selinux \
docker-engine

rm -rf /etc/systemd/system/docker.service.d

rm -rf /var/lib/docker

rm -rf /var/run/docker

2,如果清除后依旧包冲突错误

file /usr/share/man/man1/docker-manifest-annotate.1.gz from install of docker-ce-18.06.1.ce-3.el7.x86_64 conflicts with file from package docker-ce-cli-1:18.09.6-3.el7.x86_64

通过yum命令手动移除冲突包

yum erase docker-common-2:1.12.6-68.gitec8512b.el7.centos.x86_64

3,安装18.06.1版本Docker

yum install -y docker-ce-18.06.1.ce-3.el7

三,Kubernetes集群环境搭建

1,基础环境准备

a,机器节点准备,虚拟机搭建,内存不够,host名称只支持[-.]两个特殊符号

b,/etc/hosts文件设置

* 添加命令

cat >> /etc/hosts << EOF
192.168.91.136 master
192.168.91.137 node1
192.168.91.138 node2
EOF

* hosts文件配置如下

c,配置时间同步,使用chrony同步时间,配置master节点与网络NTP服务器同步时间,所有node节点与master节点同步时间

* 配置Master节点

// 安装chrony:
yum install -y chrony
// 注释默认ntp服务器
sed -i ‘s/^server/#&/’ /etc/chrony.conf
// 指定上游公共 ntp 服务器,并允许其他节点同步时间
cat >> /etc/chrony.conf << EOF
server 0.asia.pool.ntp.org iburst
server 1.asia.pool.ntp.org iburst
server 2.asia.pool.ntp.org iburst
server 3.asia.pool.ntp.org iburst
allow all
EOF
// 重启chronyd服务并设为开机启动:
systemctl enable chronyd && systemctl restart chronyd
// 开启网络时间同步功能
timedatectl set-ntp true

* 配置Node节点

// 安装chrony:
yum install -y chrony
// 注释默认服务器
sed -i ‘s/^server/#&/’ /etc/chrony.conf
// 指定内网 master节点为上游NTP服务器
echo server 192.168.91.128 iburst >> /etc/chrony.conf
// 重启服务并设为开机启动:
systemctl enable chronyd && systemctl restart chronyd

*所有节点执行chronyc sources命令,查看存在以^*开头的行,说明已经与服务器时间同步

d,设置网桥包经过iptalbes?RHEL / CentOS 7上的一些用户报告了由于iptables被绕过而导致流量路由不正确的问题。创建/etc/sysctl.d/k8s.conf文件,添加如下内容

// 添加文件内容
cat <<EOF > /etc/sysctl.d/k8s.conf
vm.swappiness = 0
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
EOF
// 使配置生效
modprobe br_netfilter
sysctl -p /etc/sysctl.d/k8s.conf

e,kube-proxy开启ipvs的前提条件?由于ipvs已经加入到了内核的主干,所以为kube-proxy开启ipvs的前提需要加载以下的内核模块: 在所有的Kubernetes节点执行以下脚本

// 添加内容
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

// 执行脚本
chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules && lsmod | grep -e ip_vs -e nf_conntrack_ipv4

f,上面脚本创建了/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。 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 ipset ipvsadm -y

g,安装kubeadm、kubelet、kubectl

// 配置kubernetes.repo的源, 由于官方源国内无法访问,这里使用阿里云yum源
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

// 在所有节点上安装指定版本 kubelet、kubeadm 和 kubectl
// 此处直接下载版本为1.15.1
yum install -y kubelet kubeadm kubectl

// 启动kubelet服务
systemctl enable kubelet && systemctl start kubelet

2,Master环境搭建

a,安装废了后,重置节点

kubeadm reset

b,初始化Master节点,注意对address和version进行更改,version与kubeadm等版本一致

kubeadm init \
–apiserver-advertise-address=192.168.91.136 \
–image-repository registry.aliyuncs.com/google_containers \
–kubernetes-version v1.15.1 \
–pod-network-cidr=10.244.0.0/16

*apiserver-advertise-address:指明用 Master 的哪个 interface 与 Cluster 的其他节点通信。如果 Master 有多个 interface,建议明确指定,如果不指定,kubeadm 会自动选择有默认网关的 interface。

*pod-network-cidr:指定 Pod 网络的范围。Kubernetes 支持多种网络方案,而且不同网络方案对 –pod-network-cidr 有自己的要求,这里设置为 10.244.0.0/16 是因为我们将使用 flannel 网络方案,必须设置成这个 CIDR。

*image-repository:Kubenetes默认Registries地址是?k8s.gcr.io,在国内并不能访问gcr.io,在1.15版本中我们可以增加–image-repository参数,默认值是k8s.gcr.io,将其指定为阿里云镜像地址:registry.aliyuncs.com/google_containers。

*kubernetes-version=v1.15.1:关闭版本探测,因为它的默认值是stable-1,会导致从https://dl.k8s.io/release/stable-1.txt下载最新的版本号,我们可以将其指定为固定版本(最新版:v1.13.1)来跳过网络请求。

c,初始化过程,及说明

[[email protected] ~]# kubeadm init –apiserver-advertise-address=192.168.91.136 –image-repository registry.aliyuncs.com/google_containers –kubernetes-version v1.15.1 –pod-network-cidr=10.244.0.0/16
[init] Using Kubernetes version: v1.15.1
[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/
[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 “front-proxy-ca” certificate and key
[certs] Generating “front-proxy-client” certificate and key
[certs] Generating “etcd/ca” certificate and key
[certs] Generating “etcd/server” certificate and key
[certs] etcd/server serving cert is signed for DNS names [master localhost] and IPs [192.168.91.136 127.0.0.1 ::1]
[certs] Generating “etcd/peer” certificate and key
[certs] etcd/peer serving cert is signed for DNS names [master localhost] and IPs [192.168.91.136 127.0.0.1 ::1]
[certs] Generating “etcd/healthcheck-client” certificate and key
[certs] Generating “apiserver-etcd-client” certificate and key
[certs] Generating “ca” certificate and key
[certs] Generating “apiserver-kubelet-client” certificate and key
[certs] Generating “apiserver” certificate and key
[certs] apiserver serving cert is signed for DNS names [master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.91.136]
[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 25.517374 seconds
[upload-config] Storing the configuration used in ConfigMap “kubeadm-config” in the “kube-system” Namespace
[kubelet] Creating a ConfigMap “kubelet-config-1.15” in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see –upload-certs
[mark-control-plane] Marking the node master as control-plane by adding the label “node-role.kubernetes.io/master=””
[mark-control-plane] Marking the node master as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: qozff5.j2weqyh2uhcz4l7f
[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 192.168.91.136:6443 –token qozff5.j2weqyh2uhcz4l7f \
–discovery-token-ca-cert-hash sha256:f427679e26a28dec67 138e2806c4ec2c03827665dd1233b11e7f60cb3c260b60

*[preflight] kubeadm 执行初始化前的检查

*[kubelet-start] 生成kubelet的配置文件”/var/lib/kubelet/config.yaml”

*[certificates] 生成相关的各种token和证书

*[certificates] 生成相关的各种token和证书

*[kubeconfig] 生成 KubeConfig 文件,kubelet 需要这个文件与 Master 通信

*[control-plane] 安装 Master 组件,会从指定的 Registry 下载组件的 Docker 镜像。

*[bootstraptoken] 生成token记录下来,后边使用kubeadm join往集群中添加节点时会用到

*[addons] 安装附加组件 kube-proxy 和 kube-dns。

*Kubernetes Master 初始化成功,提示如何配置常规用户使用kubectl访问集群。

*提示如何安装 Pod 网络。

*提示如何注册其他节点到 Cluster。

* join命令必须记住,后续需要使用join对应的token添加node节点

d,配置 kubectl:kubectl 是管理 Kubernetes Cluster 的命令行工具,前面我们已经在所有的节点安装了 kubectl。Master 初始化完成后需要做一些配置工作,然后 kubectl 就能使用了。需要这些配置命令的原因是:Kubernetes 集群默认需要加密方式访问。所以,这几条命令,就是将刚刚部署生成的 Kubernetes 集群的安全配置文件,保存到当前用户的.kube 目录下,kubectl 默认会使用这个目录下的授权信息访问 Kubernetes 集群。 如果不这么做的话,我们每次都需要通过 export KUBECONFIG 环境变量告诉 kubectl 这个安全配置文件的位置。 配置完成后centos用户就可以使用 kubectl 命令管理集群了。(此演示直接在root账号运行)

// 追加sudo权限,并配置sudo免密
sed -i ‘/^root/a\centos ALL=(ALL) NOPASSWD:ALL’ /etc/sudoers

// 保存集群安全配置文件到当前用户.kube目录
mkdir -p $HOME/.kube
cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
chown $(id -u):$(id -g) $HOME/.kube/config

// 启用 kubectl 命令自动补全功能(注销重新登录生效)
echo “source <(kubectl completion bash)” >> ~/.bashrc

e,配置好Master节点后,查看集群状态,确定每一个组件都处于healthy状态

kubectl get cs

f,确定组件都处于healthy状态后,查看节点状态

kubectl get nodes

g,只有一个Master节点,且节点处于NotReady状态。使用 kubectl describe 命令来查看这个节点(Node)对象的详细信息、状态和事件(Event)

kubectl describe node master

h,通过 kubectl describe 指令的输出,我们可以看到 NodeNotReady 的原因在于,我们尚未部署任何网络插件,kube-proxy等组件还处于starting状态。 另外,我们还可以通过 kubectl 检查这个节点上各个系统 Pod 的状态,其中,kube-system 是 Kubernetes 项目预留的系统 Pod 的工作空间(Namepsace,注意它并不是 Linux Namespace,它只是 Kubernetes 划分不同工作空间的单位),可以看到,CoreDNS依赖于网络的 Pod 都处于 Pending 状态,即调度失败。这当然是符合预期的:因为这个 Master 节点的网络尚未就绪

kubectl get pod -n kube-system -o wide

i,部署网络插件?要让 Kubernetes Cluster 能够工作,必须安装 Pod 网络,否则 Pod 之间无法通信。 Kubernetes 支持多种网络方案,这里我们使用 flannel 执行如下命令部署 flannel: kubectl apply -f kube-flannel.yml

* 上传 kube-flannel.yml 文件,文件内容如下


kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
name: flannel
rules:
– apiGroups:
– “”
resources:
– pods
verbs:
– get
– apiGroups:
– “”
resources:
– nodes
verbs:
– list
– watch
– apiGroups:
– “”
resources:
– nodes/status
verbs:
– patch

kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
name: flannel
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: flannel
subjects:
– kind: ServiceAccount
name: flannel
namespace: kube-system

apiVersion: v1
kind: ServiceAccount
metadata:
name: flannel
namespace: kube-system

kind: ConfigMap
apiVersion: v1
metadata:
name: kube-flannel-cfg
namespace: kube-system
labels:
tier: node
app: flannel
data:
cni-conf.json: |
{
“name”: “cbr0”,
“plugins”: [
{
“type”: “flannel”,
“delegate”: {
“hairpinMode”: true,
“isDefaultGateway”: true
}
},
{
“type”: “portmap”,
“capabilities”: {
“portMappings”: true
}
}
]
}
net-conf.json: |
{
“Network”: “10.244.0.0/16”,
“Backend”: {
“Type”: “vxlan”
}
}

apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
name: kube-flannel-ds-amd64
namespace: kube-system
labels:
tier: node
app: flannel
spec:
template:
metadata:
labels:
tier: node
app: flannel
spec:
hostNetwork: true
nodeSelector:
beta.kubernetes.io/arch: amd64
tolerations:
– operator: Exists
effect: NoSchedule
serviceAccountName: flannel
initContainers:
– name: install-cni
image: quay.io/coreos/flannel:v0.10.0-amd64
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: quay.io/coreos/flannel:v0.10.0-amd64
command:
– /opt/bin/flanneld
args:
– –ip-masq
– –kube-subnet-mgr
resources:
requests:
cpu: “100m”
memory: “50Mi”
limits:
cpu: “100m”
memory: “50Mi”
securityContext:
privileged: true
env:
– name: POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
– name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
volumeMounts:
– name: run
mountPath: /run
– name: flannel-cfg
mountPath: /etc/kube-flannel/
volumes:
– name: run
hostPath:
path: /run
– name: cni
hostPath:
path: /etc/cni/net.d
– name: flannel-cfg
configMap:
name: kube-flannel-cfg

apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
name: kube-flannel-ds-arm64
namespace: kube-system
labels:
tier: node
app: flannel
spec:
template:
metadata:
labels:
tier: node
app: flannel
spec:
hostNetwork: true
nodeSelector:
beta.kubernetes.io/arch: arm64
tolerations:
– operator: Exists
effect: NoSchedule
serviceAccountName: flannel
initContainers:
– name: install-cni
image: quay.io/coreos/flannel:v0.10.0-arm64
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: quay.io/coreos/flannel:v0.10.0-arm64
command:
– /opt/bin/flanneld
args:
– –ip-masq
– –kube-subnet-mgr
resources:
requests:
cpu: “100m”
memory: “50Mi”
limits:
cpu: “100m”
memory: “50Mi”
securityContext:
privileged: true
env:
– name: POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
– name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
volumeMounts:
– name: run
mountPath: /run
– name: flannel-cfg
mountPath: /etc/kube-flannel/
volumes:
– name: run
hostPath:
path: /run
– name: cni
hostPath:
path: /etc/cni/net.d
– name: flannel-cfg
configMap:
name: kube-flannel-cfg

apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
name: kube-flannel-ds-arm
namespace: kube-system
labels:
tier: node
app: flannel
spec:
template:
metadata:
labels:
tier: node
app: flannel
spec:
hostNetwork: true
nodeSelector:
beta.kubernetes.io/arch: arm
tolerations:
– operator: Exists
effect: NoSchedule
serviceAccountName: flannel
initContainers:
– name: install-cni
image: quay.io/coreos/flannel:v0.10.0-arm
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: quay.io/coreos/flannel:v0.10.0-arm
command:
– /opt/bin/flanneld
args:
– –ip-masq
– –kube-subnet-mgr
resources:
requests:
cpu: “100m”
memory: “50Mi”
limits:
cpu: “100m”
memory: “50Mi”
securityContext:
privileged: true
env:
– name: POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
– name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
volumeMounts:
– name: run
mountPath: /run
– name: flannel-cfg
mountPath: /etc/kube-flannel/
volumes:
– name: run
hostPath:
path: /run
– name: cni
hostPath:
path: /etc/cni/net.d
– name: flannel-cfg
configMap:
name: kube-flannel-cfg

apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
name: kube-flannel-ds-ppc64le
namespace: kube-system
labels:
tier: node
app: flannel
spec:
template:
metadata:
labels:
tier: node
app: flannel
spec:
hostNetwork: true
nodeSelector:
beta.kubernetes.io/arch: ppc64le
tolerations:
– operator: Exists
effect: NoSchedule
serviceAccountName: flannel
initContainers:
– name: install-cni
image: quay.io/coreos/flannel:v0.10.0-ppc64le
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: quay.io/coreos/flannel:v0.10.0-ppc64le
command:
– /opt/bin/flanneld
args:
– –ip-masq
– –kube-subnet-mgr
resources:
requests:
cpu: “100m”
memory: “50Mi”
limits:
cpu: “100m”
memory: “50Mi”
securityContext:
privileged: true
env:
– name: POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
– name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
volumeMounts:
– name: run
mountPath: /run
– name: flannel-cfg
mountPath: /etc/kube-flannel/
volumes:
– name: run
hostPath:
path: /run
– name: cni
hostPath:
path: /etc/cni/net.d
– name: flannel-cfg
configMap:
name: kube-flannel-cfg

apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
name: kube-flannel-ds-s390x
namespace: kube-system
labels:
tier: node
app: flannel
spec:
template:
metadata:
labels:
tier: node
app: flannel
spec:
hostNetwork: true
nodeSelector:
beta.kubernetes.io/arch: s390x
tolerations:
– operator: Exists
effect: NoSchedule
serviceAccountName: flannel
initContainers:
– name: install-cni
image: quay.io/coreos/flannel:v0.10.0-s390x
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: quay.io/coreos/flannel:v0.10.0-s390x
command:
– /opt/bin/flanneld
args:
– –ip-masq
– –kube-subnet-mgr
resources:
requests:
cpu: “100m”
memory: “50Mi”
limits:
cpu: “100m”
memory: “50Mi”
securityContext:
privileged: true
env:
– name: POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
– name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
volumeMounts:
– name: run
mountPath: /run
– name: flannel-cfg
mountPath: /etc/kube-flannel/
volumes:
– name: run
hostPath:
path: /run
– name: cni
hostPath:
path: /etc/cni/net.d
– name: flannel-cfg
configMap:
name: kube-flannel-cfg

* 执行文件

kubectl apply -f kube-flannel.yml

j,安装成功flannel网络插件后,重新查看POD状态。圈出来的部分,可能会存在短暂的init状态,稍等即可

*pod状态为Pending、ContainerCreating、ImagePullBackOff 都表明 Pod 没有就绪,Running 才是就绪状态,如果pod状态异常,可以通过命令拉取异常信息

// kube-flannel-ds-amd64-d2r8p 表示pod名称
kubectl describe pod kube-flannel-ds-amd64-d2r8p –namespace=kube-system

k,重新查看节点状态,节点状态从notReady转为ready,Master节点部署完成,在默认情况下,Kubernetes 的 Master 节点是不能运行用户 Pod 的。

3,Worker环境搭建

a,执行init时候提示的join语句,显示下列信息说明添加成功

kubeadm join 192.168.91.136:6443 –token qozff5. j2weqyh2uhcz4l7f \
–discovery-token-ca-cert-hash sha256:f427679e26a28dec67138 e2806c4ec2c03827665dd1233b11e7f60cb3c260b60

b,如果忘了记住join信息,可以通过语句重新生成

kubeadm token create –print-join-command

c,重复上一步添加node2节点,添加后,在master节点查看节点及pod。如果存在NotReady节点,可以稍等会,等pod全部启动,或者查看pod状态,对不是Running状态的pod进行具体分析!(pod状态为Pending、ContainerCreating、ImagePullBackOff 都表明 Pod 没有就绪)

d,集群至此,全部搭建完成

四,集群验证

1,首先验证kube-apiserver, kube-controller-manager, kube-scheduler, pod network 是否正常:?部署一个 Nginx Deployment,包含2个Pod?

a,创建

// 创建deployment nginx
[[email protected] admin]# kubectl create deployment nginx –image=nginx:alpine
deployment.apps/nginx created
// 设置为两个副本
[[email protected] admin]# kubectl scale deployment nginx –replicas=2
deployment.extensions/nginx scaled

b,查看

[[email protected] admin]# kubectl get pods -l app=nginx -o wide

2,再验证一下kube-proxy是否正常:以 NodePort 方式对外提供服务

// 以NodePort运行,并开放80端口
[[email protected] admin]# kubectl expose deployment nginx –port=80 –type=NodePort
service/nginx exposed
// 查看详情
[[email protected] admin]# kubectl get services nginx
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
nginx NodePort 10.98.47.23 <none> 80:30018/TCP 5s

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