Kubernetes-v1.12.0基于kubeadm部署

1.主机规划

#master节点(etcd/apiserver/scheduler/controller manager)
master.example.com
eth0:  192.168.0.135
eth1:  192.168.1.53

#node1
node1.example.com
eth0: 192.168.0.136
eth1: 192.168.1.54

#node2
node2.example.com
eth0: 192.168.0.137
eth1: 192.168.1.55

2.安装kubeadm

[root@master ~]# systemctl start docker
[root@master ~]# systemctl enable docker

yum install -y kubelet kubeadm kubectl kubernetes-cni
systemctl enable kubelet && systemctl start kubelet

3.下载镜像并更新tag

#coding:utf8
import os

S_registry = 'registry.cn-hangzhou.aliyuncs.com/bubblelin/'
D_registry = 'k8s.gcr.io/'

master_image = ['kube-apiserver:v1.12.0','kube-controller-manager:v1.12.0',
                'kube-scheduler:v1.12.0','kube-proxy:v1.12.0','pause:3.1',
                'etcd:3.2.24','coredns:1.2.2']

def PullImage(registry,images):
    print("一共%s个镜像" %(len(images),))
    index = 1
    for image in images:
        print("开始下载第[%d]个镜像 ---> [%s]" %(index,image))
        cmd = "docker pull " + registry + image
        os.system(cmd)
        print("done!")
        index +=1

def TagImage(sregistry,dregistry,images):
    print("一共%s个镜像" %(len(images),))
    index = 1
    for image in images:
        print("开始tag第[%d]个镜像 ---> [%s]  --->[%s]" %(index,sregistry+image,dregistry+image))
        cmd = "docker tag " + sregistry+image + " " +  dregistry + image
        os.system(cmd)
        print("done!")
        index +=1

if __name__ == '__main__':
    #PullImage(S_registry,master_image)
    TagImage(S_registry,D_registry,master_image)

4.初始化

[root@master ~]# kubeadm init --kubernetes-version=v1.12.0 --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=192.168.0.135
[init] using Kubernetes version: v1.12.0
[preflight] running pre-flight checks
	[WARNING Firewalld]: firewalld is active, please ensure ports [6443 10250] are open or your cluster may not function correctly
	[WARNING Service-Docker]: docker service is not enabled, please run 'systemctl enable docker.service'
[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 [master.example.com kubernetes kubernetes.default kubernetes.default.svc kubern
etes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.0.135][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 etcd/healthcheck-client 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 [master.example.com 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 [master.example.com localhost] and IPs [192.168.0.135 127.0.0.1 ::1]
[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 40.010009 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 master.example.com as master by adding the label "node-role.kubernetes.io/master=''"
[markmaster] Marking the node master.example.com 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 "master.example.com" as an annotation
[bootstraptoken] using token: 33x3h7.tejszerd0znwtjum
[bootstraptoken] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credential
s[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 192.168.0.135:6443 --token 33x3h7.tejszerd0znwtjum --discovery-token-ca-cert-hash sha256:2d790600988cf71dda1a5f2ea2e798918acf5
4584ff3ffe1dca006ec8a4c80a6

5.验证

[root@master ~]# export KUBECONFIG=/etc/kubernetes/admin.conf
[root@master ~]# kubectl get nodes
NAME                 STATUS     ROLES    AGE   VERSION
master.example.com   NotReady   master   11m   v1.12.3
[root@master ~]# kubectl get pods --all-namespaces
NAMESPACE     NAME                                         READY   STATUS    RESTARTS   AGE
kube-system   coredns-576cbf47c7-6mvtt                     /     Pending             11m
kube-system   coredns-576cbf47c7-djzgn                     /     Pending             11m
kube-system   etcd-master.example.com                      /     Running             10m
kube-system   kube-apiserver-master.example.com            /     Running             11m
kube-system   kube-controller-manager-master.example.com   /     Running             10m
kube-system   kube-proxy-wj62f                             /     Running             11m
kube-system   kube-scheduler-master.example.com            /     Running             11m

6.网络配置

wget https://raw.githubusercontent.com/coreos/flannel/v0.10.0/Documentation/kube-flannel.yml

docker pull registry.cn-hangzhou.aliyuncs.com/kubernetes1112images/flannel:v0.10.0-amd64

docker tag registry.cn-hangzhou.aliyuncs.com/kubernetes_containers/flannel:v0.10.0-amd64 quay.io/coreos/flannel:v0.10.0-amd64

[root@master ~]# vim kube-flannel.yml
      containers:
      - name: kube-flannel
        image: quay.io/coreos/flannel:v0.10.0-amd64
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        - --iface=ens33   #指定网卡

[root@master ~]# kubectl apply -f kube-flannel.yml

7.添加节点

下载镜像

#coding:utf8
import os

S_registry = 'registry.cn-hangzhou.aliyuncs.com/bubblelin/'
D_registry = 'k8s.gcr.io/'

node_image = [ 'kube-proxy:v1.12.0','pause:3.1',]

def PullImage(registry,images):
    print("一共%s个镜像" %(len(images),))
    index = 1
    for image in images:
        print("开始下载第[%d]个镜像 ---> [%s]" %(index,image))
        cmd = "docker pull " + registry + image
        os.system(cmd)
        print("done!")
        index +=1

def TagImage(sregistry,dregistry,images):
    print("一共%s个镜像" %(len(images),))
    index = 1
    for image in images:
        print("开始tag第[%d]个镜像 ---> [%s]  --->[%s]" %(index,sregistry+image,dregistry+image))
        cmd = "docker tag " + sregistry+image + " " +  dregistry + image
        os.system(cmd)
        print("done!")
        index +=1

if __name__ == '__main__':
    PullImage(S_registry,node_image)
    TagImage(S_registry,D_registry,node_image)

2.kubeadm添加

[root@node1 ~]# kubeadm join 192.168.0.135: --token 33x3h7.tejszerd0znwtjum --discovery-token-ca-cert-hash sha256:2d790600988cf71dda1a5f2
ea2e798918acf54584ff3ffe1dca006ec8a4c80a6[preflight] running pre-flight checks
    [WARNING RequiredIPVSKernelModulesAvailable]: the IPVS proxier will not be used, because the following required kernel modules are no
t loaded: [ip_vs_wrr ip_vs_sh ip_vs ip_vs_rr] or no builtin kernel ipvs support: map[ip_vs:{} ip_vs_rr:{} ip_vs_wrr:{} ip_vs_sh:{} nf_conntrack_ipv4:{}]you can solve this problem with following methods:
 . Run 'modprobe -- ' to load missing kernel modules;
. Provide the missing builtin kernel ipvs support

    [WARNING Service-Docker]: docker service is not enabled, please run 'systemctl enable docker.service'
[discovery] Trying to connect to API Server "192.168.0.135:6443"
[discovery] Created cluster-info discovery client, requesting info from "https://192.168.0.135:6443"
[discovery] Requesting info from "https://192.168.0.135:6443" again to validate TLS against the pinned public key
[discovery] Cluster info signature and contents are valid and TLS certificate validates against pinned roots, will use API Server "192.168.0.
:"[discovery] Successfully established connection with API Server "192.168.0.135:"
[kubelet] Downloading configuration for the kubelet from the "kubelet-config-1.12" ConfigMap in the kube-system namespace
[kubelet] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[preflight] Activating the kubelet service
[tlsbootstrap] Waiting for the kubelet to perform the TLS Bootstrap...
[patchnode] Uploading the CRI Socket information "/var/run/dockershim.sock" to the Node API object "node1.example.com" as an annotation

This node has joined the cluster:
* Certificate signing request was sent to apiserver 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.

8.FAQ

1.发现coredns出现问题，pod状态一直是pendding状态。

kubectl descripe pod xxxx -n kube-system

Warning  FailedScheduling  21m (x243 over 61m)   default-scheduler  0/1 nodes are available: 1 node(s) had taints that the pod didn't toler
ate.  Warning  FailedScheduling  4m47s (x61 over 14m)  default-scheduler  0/1 nodes are available: 1 node(s) had taints that the pod didn't toler
ate.

正常： 百度taints 污点，应为没有添加node节点导致。 默认不会给master节点分配pod。

[root@master ~]# kubectl describe node master.example.com |grep -E '(Roles|Taints)'
Roles:              master
Taints:             node-role.kubernetes.io/master:NoSchedule

2.防火墙问题

经过telnet 发现no route tohost  。 关闭防火墙即可。

info: dial tcp 192.168.0.135:6443: connect: no route to host][discovery] Failed to request cluster info, will try again: [Get https://192.168.0.135:6443/api/v1/namespaces/kube-public/configmaps/cluster-
info: dial tcp 192.168.0.135:6443: connect: no route to host]

参考链接：https://www.cnblogs.com/cocowool/p/kubeadm_install_kubernetes.html