我是Kubernetes的新手，所以我的一些问题可能是基本的。
我的设置：2个VM（运行Ubuntu 16.04.2）
Kubernetes版本：主节点（kube4local）和从节点（kube5local）上的1.7.1 我的步骤：1。 在主节点和从节点上，安装了所需的kubernetes（kubelet kubeadm kubectl kubernetes-cni）包和docker（docker.io）包。 在主节点上：1。
vagrant@kube4local:~$ sudo kubeadm init
[kubeadm] WARNING: kubeadm is in beta, please do not use it for production clusters.
[init] Using Kubernetes version: v1.7.1
[init] Using Authorization modes: [Node RBAC]
[preflight] Running pre-flight checks
[preflight] WARNING: docker version is greater than the most recently validated version. Docker version: 17.06.0-ce. Max validated version: 1.12
[certificates] Generated CA certificate and key.
[certificates] Generated API server certificate and key.
[certificates] API Server serving cert is signed for DNS names [kube4local kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 10.0.2.15]
[certificates] Generated API server kubelet client certificate and key.
[certificates] Generated service account token signing key and public key.
[certificates] Generated front-proxy CA certificate and key.
[certificates] Generated front-proxy client certificate and key.
[certificates] Valid certificates and keys now exist in "/etc/kubernetes/pki"
[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"
[apiclient] Created API client, waiting for the control plane to become ready
[apiclient] All control plane components are healthy after 1051.552012 seconds
[token] Using token: 3c68b6.8c3f8d5a0a29a3ac
[apiconfig] Created RBAC rules
[addons] Applied essential addon: kube-proxy
[addons] Applied essential addon: kube-dns
Your Kubernetes master has initialized successfully!
To start using your cluster, you need to run (as a regular user):
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
http://kubernetes.io/docs/admin/addons/
You can now join any number of machines by running the following on each node
as root:
kubeadm join --token 3c68b6.8c3f8d5a0a29a3ac 10.0.2.15:6443
vagrant@kube4local:~$ mkdir -p $HOME/.kube
vagrant@kube4local:~$ sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
vagrant@kube4local:~$ sudo chown $(id -u):$(id -g) $HOME/.kube/config
vagrant@kube4local:~$ sudo kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"
serviceaccount "weave-net" created
clusterrole "weave-net" created
clusterrolebinding "weave-net" created
daemonset "weave-net" created
在从节点上：
注意：我能够进行基本的ping测试，并且在VM1中运行的主节点和在VM2中运行的从节点之间的ssh，scp命令工作正常。
执行join命令。 从节点中输出join命令：
vagrant@kube5local:~$ sudo kubeadm join --token 3c68b6.8c3f8d5a0a29a3ac 10.0.2.15:6443
[kubeadm] WARNING: kubeadm is in beta, please do not use it for production clusters.
[preflight] Running pre-flight checks
[preflight] WARNING: docker version is greater than the most recently validated version. Docker version: 17.06.0-ce. Max validated version: 1.12
[preflight] WARNING: hostname "" could not be reached
[preflight] WARNING: hostname "" lookup : no such host
[preflight] Some fatal errors occurred:
hostname "" a DNS-1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')
[preflight] If you know what you are doing, you can skip pre-flight checks with `--skip-preflight-checks`
为什么我收到此错误，我的/ etc / hosts更正：
[preflight] WARNING: hostname "" could not be reached
[preflight] WARNING: hostname "" lookup : no such host
在主节点上输出状态命令：
vagrant@kube4local:~$ sudo kubectl cluster-info
Kubernetes master is running at https://10.0.2.15:6443
vagrant@kube4local:~$ sudo kubectl get nodes
NAME STATUS AGE VERSION
kube4local Ready 26m v1.7.1
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
在主节点（kube4local）上输出ifconfig：
vagrant@kube4local:~$ ifconfig
docker0 Link encap:Ethernet HWaddr 02:42:3a:c4:00:50
inet addr:172.17.0.1 Bcast:0.0.0.0 Mask:255.255.0.0
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
enp0s3 Link encap:Ethernet HWaddr 08:00:27:19:2c:a4
inet addr:10.0.2.15 Bcast:10.0.2.255 Mask:255.255.255.0
inet6 addr: fe80::a00:27ff:fe19:2ca4/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:260314 errors:0 dropped:0 overruns:0 frame:0
TX packets:58921 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:334293914 (334.2 MB) TX bytes:3918136 (3.9 MB)
enp0s8 Link encap:Ethernet HWaddr 08:00:27:b8:ef:b6
inet addr:192.168.56.104 Bcast:192.168.56.255 Mask:255.255.255.0
inet6 addr: fe80::a00:27ff:feb8:efb6/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:247 errors:0 dropped:0 overruns:0 frame:0
TX packets:154 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:36412 (36.4 KB) TX bytes:25999 (25.9 KB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:19922 errors:0 dropped:0 overruns:0 frame:0
TX packets:19922 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:1996565 (1.9 MB) TX bytes:1996565 (1.9 MB)
主节点（kube4local）上的/ etc / hosts输出：
vagrant@kube4local:~$ cat /etc/hosts
192.168.56.104 kube4local kube4local
192.168.56.105 kube5local kube5local
127.0.1.1 vagrant.vm vagrant
::1 localhost ip6-localhost ip6-loopback
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
从节点（kube5local）输出ifconfig：
vagrant@kube5local:~$ ifconfig
docker0 Link encap:Ethernet HWaddr 02:42:bb:37:ab:35
inet addr:172.17.0.1 Bcast:0.0.0.0 Mask:255.255.0.0
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
enp0s3 Link encap:Ethernet HWaddr 08:00:27:19:2c:a4
inet addr:10.0.2.15 Bcast:10.0.2.255 Mask:255.255.255.0
inet6 addr: fe80::a00:27ff:fe19:2ca4/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:163514 errors:0 dropped:0 overruns:0 frame:0
TX packets:39792 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:207478954 (207.4 MB) TX bytes:2660902 (2.6 MB)
enp0s8 Link encap:Ethernet HWaddr 08:00:27:6a:f0:51
inet addr:192.168.56.105 Bcast:192.168.56.255 Mask:255.255.255.0
inet6 addr: fe80::a00:27ff:fe6a:f051/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:195 errors:0 dropped:0 overruns:0 frame:0
TX packets:151 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:30463 (30.4 KB) TX bytes:26737 (26.7 KB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
从节点（kube4local）上的/ etc / hosts输出：
vagrant@kube5local:~$ cat /etc/hosts
192.168.56.104 kube4local kube4local
192.168.56.105 kube5local kube5local
127.0.1.1 vagrant.vm vagrant
::1 localhost ip6-localhost ip6-loopback
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
答案 0 :(得分：1)
Nat这是版本v1.7.1中的错误。您可以使用v1.7.0版本或跳过飞行前检查。
kubeadm join --skip-preflight-checks
您可以参考此主题以获取更多详细信息。
kubernets v1.7.1 kubeadm join hostname "" could not be reached error