怎样使用Kubeadm安装Kubernetes1.5版本，针对这个问题，这篇文章详细介绍了相对应的分析和解答，希望可以帮助更多想解决这个问题的小伙伴找到更简单易行的方法。
使用Kubeadm安装Kubernetes1.5版本
1、系统版本：ubuntu16.04
root@master:~# docker version
Client:
Version: 1.12.1
API version: 1.24
Go version: go1.6.2
Git commit: 23cf638
Built: Tue, 27 Sep 2016 12:25:38 +1300
OS/Arch: linux/amd64
Server:
Version: 1.12.1
API version: 1.24
Go version: go1.6.2
Git commit: 23cf638
Built: Tue, 27 Sep 2016 12:25:38 +1300
OS/Arch: linux/amd64
1、部署前提条件
每台主机上面至少1G内存。
所有主机之间网络可达。
2、部署：
在主机上安装kubelet和kubeadm
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
我是用的是
http://119.29.98.145:8070/zhi/apt-key.gpg
主机master上操作如下：
curl -s http://119.29.98.145:8070/zhi/apt-key.gpg | apt-key add -
cat <<EOF >/etc/apt/sources.list.d/kubernetes.list
deb http://apt.kubernetes.io/ kubernetes-xenial main
EOF
apt-get update
apt-get install -y docker.io
apt-get install -y kubelet kubeadm kubectl kubernetes-cni
下载后的kube组件并未自动运行起来。在 /lib/systemd/system下面我们能看到kubelet.service
root@master:~# ls /lib/systemd/system |grep kube
kubelet.service
kubelet的版本：
root@master:~# kubelet --version
Kubernetes v1.5.1
k8s的核心组件都有了，接下来我们就要boostrap kubernetes cluster了。
3、初始化集群
理论上通过kubeadm使用init和join命令即可建立一个集群，这init就是在master节点对集群进行初始化。和k8s 1.4之前的部署方式不同的是，
kubeadm安装的k8s核心组件都是以容器的形式运行于master node上的。因此在kubeadm init之前，最好给master node上的docker engine挂上加速器代理，
因为kubeadm要从gcr.io/google_containers repository中pull许多核心组件的images
在Kubeadm的文档中，Pod Network的安装是作为一个单独的步骤的。kubeadm init并没有为你选择一个默认的Pod network进行安装。
我们将首选Flannel 作为我们的Pod network，这不仅是因为我们的上一个集群用的就是flannel，而且表现稳定。
更是由于Flannel就是coreos为k8s打造的专属overlay network add-ons。甚至于flannel repository的readme.md都这样写着：“flannel is a network fabric for containers, designed for Kubernetes”。
如果我们要使用Flannel，那么在执行init时，按照kubeadm文档要求，我们必须给init命令带上option：–pod-network-cidr=10.244.0.0/16。
4、执行kubeadm init
执行kubeadm init命令：
root@master:~# kubeadm init --pod-network-cidr=10.244.0.0/16
[kubeadm] WARNING: kubeadm is in alpha, please do not use it for production clusters.
[preflight] Running pre-flight checks
[preflight] Starting the kubelet service
[init] Using Kubernetes version: v1.5.1
[tokens] Generated token: "2909ca.c0b0772a8817f9e3"
[certificates] Generated Certificate Authority key and certificate.
[certificates] Generated API Server key and certificate
[certificates] Generated Service Account signing keys
[certificates] Created keys and certificates in "/etc/kubernetes/pki"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/kubelet.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/admin.conf"
[apiclient] Created API client, waiting for the control plane to become ready
[apiclient] All control plane components are healthy after 14.761716 seconds
[apiclient] Waiting for at least one node to register and become ready
[apiclient] First node is ready after 1.003312 seconds
[apiclient] Creating a test deployment
[apiclient] Test deployment succeeded
[token-discovery] Created the kube-discovery deployment, waiting for it to become ready
[token-discovery] kube-discovery is ready after 1.002402 seconds
[addons] Created essential addon: kube-proxy
[addons] Created essential addon: kube-dns
Your Kubernetes master has initialized successfully!
You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
http://kubernetes.io/docs/admin/addons/
You can now join any number of machines by running the following on each node:
kubeadm join --token=2909ca.c0b0772a8817f9e3 xxx.xxx.xxx.xxx (ip记下)
init成功后的master node有啥变化？k8s的核心组件均正常启动：
root@master:~# ps -ef |grep kube
root 23817 1 2 14:07 ? 00:00:35 /usr/bin/kubelet --kubeconfig=/etc/kubernetes/kubelet.conf --require-kubeconfig=true --pod-manifest-path=/etc/kubernetes/manifests --allow-privileged=true --network-plugin=cni --cni-conf-dir=/etc/cni/net.d --cni-bin-dir=/opt/cni/bin --cluster-dns=10.96.0.10 --cluster-domain=cluster.local
root 23921 23900 0 14:07 ? 00:00:01 kube-scheduler --address=127.0.0.1 --leader-elect --master=127.0.0.1:8080
root 24055 24036 0 14:07 ? 00:00:10 kube-apiserver --insecure-bind-address=127.0.0.1 --admission-control=NamespaceLifecycle,LimitRanger,ServiceAccount,PersistentVolumeLabel,DefaultStorageClass,ResourceQuota --service-cluster-ip-range=10.96.0.0/12 --service-account-key-file=/etc/kubernetes/pki/apiserver-key.pem --client-ca-file=/etc/kubernetes/pki/ca.pem --tls-cert-file=/etc/kubernetes/pki/apiserver.pem --tls-private-key-file=/etc/kubernetes/pki/apiserver-key.pem --token-auth-file=/etc/kubernetes/pki/tokens.csv --secure-port=6443 --allow-privileged --advertise-address=master的ip --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --anonymous-auth=false --etcd-servers=http://127.0.0.1:2379
root 24084 24070 0 14:07 ? 00:00:11 kube-controller-manager --address=127.0.0.1 --leader-elect --master=127.0.0.1:8080 --cluster-name=kubernetes --root-ca-file=/etc/kubernetes/pki/ca.pem --service-account-private-key-file=/etc/kubernetes/pki/apiserver-key.pem --cluster-signing-cert-file=/etc/kubernetes/pki/ca.pem --cluster-signing-key-file=/etc/kubernetes/pki/ca-key.pem --insecure-experimental-approve-all-kubelet-csrs-for-group=system:kubelet-bootstrap --allocate-node-cidrs=true --cluster-cidr=10.244.0.0/16
root 24242 24227 0 14:07 ? 00:00:00 /usr/local/bin/kube-discovery
root 24308 24293 1 14:07 ? 00:00:15 kube-proxy --kubeconfig=/run/kubeconfig
root 29457 29441 0 14:09 ? 00:00:00 /opt/bin/flanneld --ip-masq --kube-subnet-mgr
root 29498 29481 0 14:09 ? 00:00:00 /bin/sh -c set -e -x; cp -f /etc/kube-flannel/cni-conf.json /etc/cni/net.d/10-flannel.conf; while true; do sleep 3600; done
root 30372 30357 0 14:10 ? 00:00:01 /exechealthz --cmd=nslookup kubernetes.default.svc.cluster.local 127.0.0.1 >/dev/null --url=/healthz-dnsmasq --cmd=nslookup kubernetes.default.svc.cluster.local 127.0.0.1:10053 >/dev/null --url=/healthz-kubedns --port=8080 --quiet
root 30682 30667 0 14:10 ? 00:00:01 /kube-dns --domain=cluster.local --dns-port=10053 --config-map=kube-dns --v=2
root 48755 1796 0 14:31 pts/0 00:00:00 grep --color=auto kube
而且以多cotainer的形式启动
root@master:~# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
c4209b1077d2 gcr.io/google_containers/kubedns-amd64:1.9 "/kube-dns --domain=c" 22 minutes ago Up 22 minutes k8s_kube-dns.61e5a20f_kube-dns-2924299975-txh2v_kube-system_f5364cd5-d631-11e6-9d86-0050569c3e9b_fc02f762
0908d6398b0b gcr.io/google_containers/exechealthz-amd64:1.2 "/exechealthz '--cmd=" 22 minutes ago Up 22 minutes k8s_healthz.9d343f54_kube-dns-2924299975-txh2v_kube-system_f5364cd5-d631-11e6-9d86-0050569c3e9b_0ee806f6
0e35e96ca4ac gcr.io/google_containers/dnsmasq-metrics-amd64:1.0 "/dnsmasq-metrics --v" 22 minutes ago Up 22 minutes k8s_dnsmasq-metrics.2bb05ef7_kube-dns-2924299975-txh2v_kube-system_f5364cd5-d631-11e6-9d86-0050569c3e9b_436b9370
3921b4e59aca gcr.io/google_containers/kube-dnsmasq-amd64:1.4 "/usr/sbin/dnsmasq --" 22 minutes ago Up 22 minutes k8s_dnsmasq.f7e18a01_kube-dns-2924299975-txh2v_kube-system_f5364cd5-d631-11e6-9d86-0050569c3e9b_06c5efa7
18513413ba60 gcr.io/google_containers/pause-amd64:3.0 "/pause" 22 minutes ago Up 22 minutes k8s_POD.d8dbe16c_kube-dns-2924299975-txh2v_kube-system_f5364cd5-d631-11e6-9d86-0050569c3e9b_9de0a18d
45132c8d6d3d quay.io/coreos/flannel-git:v0.6.1-28-g5dde68d-amd64 "/bin/sh -c 'set -e -" 23 minutes ago Up 23 minutes k8s_install-cni.fc218cef_kube-flannel-ds-0fnxc_kube-system_22034e49-d632-11e6-9d86-0050569c3e9b_88dffd75
4c2a2e46c808 quay.io/coreos/flannel-git:v0.6.1-28-g5dde68d-amd64 "/opt/bin/flanneld --" 23 minutes ago Up 23 minutes k8s_kube-flannel.5fdd90ba_kube-flannel-ds-0fnxc_kube-system_22034e49-d632-11e6-9d86-0050569c3e9b_2706c3cb
ad08c8dd177c gcr.io/google_containers/pause-amd64:3.0 "/pause" 23 minutes ago Up 23 minutes k8s_POD.d8dbe16c_kube-flannel-ds-0fnxc_kube-system_22034e49-d632-11e6-9d86-0050569c3e9b_279d8436
847f00759977 gcr.io/google_containers/kube-proxy-amd64:v1.5.1 "kube-proxy --kubecon" 24 minutes ago Up 24 minutes k8s_kube-proxy.2f62b4e5_kube-proxy-9c0bf_kube-system_f5326252-d631-11e6-9d86-0050569c3e9b_c1f31904
f8da0f38f3e1 gcr.io/google_containers/pause-amd64:3.0 "/pause" 24 minutes ago Up 24 minutes k8s_POD.d8dbe16c_kube-proxy-9c0bf_kube-system_f5326252-d631-11e6-9d86-0050569c3e9b_c340d947
c1efa29640d1 gcr.io/google_containers/kube-discovery-amd64:1.0 "/usr/local/bin/kube-" 24 minutes ago Up 24 minutes k8s_kube-discovery.6907cb07_kube-discovery-1769846148-4rsq9_kube-system_f49933be-d631-11e6-9d86-0050569c3e9b_c4827da2
4c6a646d0b2e gcr.io/google_containers/pause-amd64:3.0 "/pause" 24 minutes ago Up 24 minutes k8s_POD.d8dbe16c_kube-discovery-1769846148-4rsq9_kube-system_f49933be-d631-11e6-9d86-0050569c3e9b_8823b66a
ece79181f177 gcr.io/google_containers/pause-amd64:3.0 "/pause" 24 minutes ago Up 24 minutes k8s_dummy.702d1bd5_dummy-2088944543-r2mw3_kube-system_f38f3ede-d631-11e6-9d86-0050569c3e9b_ade728ba
9c3364c623df gcr.io/google_containers/pause-amd64:3.0 "/pause" 24 minutes ago Up 24 minutes k8s_POD.d8dbe16c_dummy-2088944543-r2mw3_kube-system_f38f3ede-d631-11e6-9d86-0050569c3e9b_838c58b5
a64a3363a82b gcr.io/google_containers/kube-controller-manager-amd64:v1.5.1 "kube-controller-mana" 25 minutes ago Up 25 minutes k8s_kube-controller-manager.84edb2e5_kube-controller-manager-master_kube-system_7b7c15f8228e3413d3b0d0bad799b1ea_697ef6ee
27625502c298 gcr.io/google_containers/kube-apiserver-amd64:v1.5.1 "kube-apiserver --ins" 25 minutes ago Up 25 minutes k8s_kube-apiserver.5942f3e3_kube-apiserver-master_kube-system_aeb59dd32f3217b366540250d2c35d8c_38a83844
5b2cc5cb9ac1 gcr.io/google_containers/pause-amd64:3.0 "/pause" 25 minutes ago Up 25 minutes k8s_POD.d8dbe16c_kube-controller-manager-master_kube-system_7b7c15f8228e3413d3b0d0bad799b1ea_2f88a796
e12ef7b3c1f0 gcr.io/google_containers/etcd-amd64:3.0.14-kubeadm "etcd --listen-client" 25 minutes ago Up 25 minutes k8s_etcd.c323986f_etcd-master_kube-system_3a26566bb004c61cd05382212e3f978f_ef6eb513
84a731cbce18 gcr.io/google_containers/pause-amd64:3.0 "/pause" 25 minutes ago Up 25 minutes k8s_POD.d8dbe16c_kube-apiserver-master_kube-system_aeb59dd32f3217b366540250d2c35d8c_a3a2ea4e
612b021457a1 gcr.io/google_containers/kube-scheduler-amd64:v1.5.1 "kube-scheduler --add" 25 minutes ago Up 25 minutes k8s_kube-scheduler.bb7d750_kube-scheduler-master_kube-system_0545c2e223307b5ab8c74b0ffed56ac7_a49fab86
ac0d8698f79f gcr.io/google_containers/pause-amd64:3.0 "/pause" 25 minutes ago Up 25 minutes k8s_POD.d8dbe16c_etcd-master_kube-system_3a26566bb004c61cd05382212e3f978f_9a6b7925
2a16a2217bf3 gcr.io/google_containers/pause-amd64:3.0 "/pause" 25 minutes ago Up 25 minutes k8s_POD.d8dbe16c_kube-scheduler-master_kube-system_0545c2e223307b5ab8c74b0ffed56ac7_d2b51317
kube-apiserver的IP是host ip，从而推断容器使用的是host网络，这从其对应的pause容器的network属性就可以看出：
root@master:~# docker ps |grep apiserver
27625502c298 gcr.io/google_containers/kube-apiserver-amd64:v1.5.1 "kube-apiserver --ins" 26 minutes ago Up 26 minutes k8s_kube-apiserver.5942f3e3_kubeapiserver-master_kube-system_aeb59dd32f3217b366540250d2c35d8c_38a83844
84a731cbce18 gcr.io/google_containers/pause-amd64:3.0 "/pause" 26 minutes ago Up 26 minutes k8s_POD.d8dbe16c_kube-apiserver-master_kube-system_aeb59dd32f3217b366540250d2c35d8c_a3a2ea4e
问题一、
如果kubeadm init执行过程中途出现了什么问题，比如前期忘记挂加速器导致init hang住，你可能会ctrl+c退出init执行。重新配置后，再执行kubeadm init，这时你可能会遇到下面kubeadm的输出：
# kubeadm init --pod-network-cidr=10.244.0.0/16
[kubeadm] WARNING: kubeadm is in alpha, please do not use it for production clusters.
[preflight] Running pre-flight checks
[preflight] Some fatal errors occurred:
Port 10250 is in use
/etc/kubernetes/manifests is not empty
/etc/kubernetes/pki is not empty
/var/lib/kubelet is not empty
/etc/kubernetes/admin.conf already exists
/etc/kubernetes/kubelet.conf already exists
[preflight] If you know what you are doing, you can skip pre-flight checks with `--skip-preflight-checks`
kubeadm会自动检查当前环境是否有上次命令执行的“残留”。如果有，必须清理后再行执行init。我们可以通过”kubeadm reset”来清理环境，以备重来。
# kubeadm reset
[preflight] Running pre-flight checks
[reset] Draining node: "iz25beglnhtz"
[reset] Removing node: "iz25beglnhtz"
[reset] Stopping the kubelet service
[reset] Unmounting mounted directories in "/var/lib/kubelet"
[reset] Removing kubernetes-managed containers
[reset] Deleting contents of stateful directories: [/var/lib/kubelet /etc/cni/net.d /var/lib/etcd]
[reset] Deleting contents of config directories: [/etc/kubernetes/manifests /etc/kubernetes/pki]
[reset] Deleting files: [/etc/kubernetes/admin.conf /etc/kubernetes/kubelet.conf]
5、要使用Flannel网络，因此我们需要执行如下安装命令：
#kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
configmap "kube-flannel-cfg" created
daemonset "kube-flannel-ds" created
需要稍等几秒钟，我们再来看master node上的cluster信息：
root@master:~# ps -ef |grep kube |grep flannel
root 29457 29441 0 14:09 ? 00:00:00 /opt/bin/flanneld --ip-masq --kube-subnet-mgr
root 29498 29481 0 14:09 ? 00:00:00 /bin/sh -c set -e -x; cp -f /etc/kube-flannel/cni-conf.json /etc/cni/net.d/10-flannel.conf; while true; do sleep 3600; done
root@master:~# kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system dummy-2088944543-r2mw3 1/1 Running 0 30m
kube-system etcd-master 1/1 Running 0 31m
kube-system kube-apiserver-master 1/1 Running 0 31m
kube-system kube-controller-manager-master 1/1 Running 0 31m
kube-system kube-discovery-1769846148-4rsq9 1/1 Running 0 30m
kube-system kube-dns-2924299975-txh2v 4/4 Running 0 30m
kube-system kube-flannel-ds-0fnxc 2/2 Running 0 29m
kube-system kube-flannel-ds-lpgpv 2/2 Running 0 23m
kube-system kube-flannel-ds-s05nr 2/2 Running 0 18m
kube-system kube-proxy-9c0bf 1/1 Running 0 30m
kube-system kube-proxy-t8hxr 1/1 Running 0 18m
kube-system kube-proxy-zd0v2 1/1 Running 0 23m
kube-system kube-scheduler-master 1/1 Running 0 31m
至少集群的核心组件已经全部run起来了。看起来似乎是成功了。
接下来开始node下的操作
6、minion node：join the cluster
这里我们用到了kubeadm的第二个命令：kubeadm join。
在minion node上执行（注意：这里要保证master node的9898端口在防火墙是打开的）：
前提node下需要有上面安装的kube组建
7、安装kubelet和kubeadm
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
我是用的是
http://119.29.98.145:8070/zhi/apt-key.gpg
主机master上操作如下：
curl -s http://119.29.98.145:8070/zhi/apt-key.gpg | apt-key add -
cat <<EOF >/etc/apt/sources.list.d/kubernetes.list
deb http://apt.kubernetes.io/ kubernetes-xenial main
EOF
apt-get update
apt-get install -y docker.io
apt-get install -y kubelet kubeadm kubectl kubernetes-cni
记住master的token
root@node01:~# kubeadm join --token=2909ca.c0b0772a8817f9e3 xxx.xxx.xxx.xxx(ip)
8、在master node上查看当前cluster状态：
root@master:~# kubectl get node
NAME STATUS AGE
master Ready,master 59m
node01 Ready 51m
node02 Ready 46m
关于怎样使用Kubeadm安装Kubernetes1.5版本问题的解答就分享到这里了，希望以上内容可以对大家有一定的帮助，如果你还有很多疑惑没有解开，可以关注天达云行业资讯频道了解更多相关知识。