title: kubeadm: master node never ready
body: <p>I'm following <a href="https://medium.com/@SystemMining/setup-kubenetes-cluster-on-ubuntu-16-04-with-kubeadm-336f4061d929" rel="noreferrer">a blog post</a> to setup a kubernetes cluster with kubeadm. So I have a Virtualbox created with bridge network and simply followed the instructions.</p>
  
  <p>I initially just did <code>kubeadm init</code> and it didn't work (master NotReady). So I figured maybe an older version might work better.</p>
  
  <p>So I did</p>
  
  <pre><code>kubeadm init --kubernetes-version v1.6.2
  </code></pre>
  
  <p>It finished quite quickly. But <code>kubeadm get nodes</code> always returns:</p>
  
  <pre><code>master    NotReady   4m        v1.6.3
  </code></pre>
  
  <p>I checked the docker images that was downloaded and they're like this:</p>
  
  <pre><code>gcr.io/google_containers/kube-proxy-amd64                v1.6.2              7a1b61b8f5d4        4 weeks ago         109.2 MB
  gcr.io/google_containers/kube-controller-manager-amd64   v1.6.2              c7ad09fe3b82        4 weeks ago         132.7 MB
  gcr.io/google_containers/kube-apiserver-amd64            v1.6.2              e14b1d5ee474        4 weeks ago         150.5 MB
  gcr.io/google_containers/kube-scheduler-amd64            v1.6.2              b55f2a2481b9        4 weeks ago         76.76 MB
  gcr.io/google_containers/etcd-amd64                      3.0.17              243830dae7dd        12 weeks ago        168.9 MB
  gcr.io/google_containers/pause-amd64                     3.0                 99e59f495ffa        12 months ago       746.9 kB
  </code></pre>
  
  <p>and output of <code>docker ps</code> shows that the following containers are using <code>pause</code></p>
  
  <pre><code>k8s_POD_kube-scheduler-master_kube-system_e4c05f51e4e89758e2fb58eb9c457e66_2
  k8s_POD_kube-controller-manager-master_kube-system_14cceb4cae4afafe5d2872cedc46b03f_2
  k8s_POD_etcd-master_kube-system_7075157cfd4524dbe0951e00a8e3129e_2
  k8s_POD_kube-apiserver-master_kube-system_bd46883c0ce86694060fb2924470cfa7_2
  </code></pre>
  
  <p>I'm a bit confused:</p>
  
  <ol>
  <li><p>Under what situation would the master node get into <code>Ready</code> state?</p></li>
  <li><p>Why the difference between the version I asked (and the docker images tag) and the version reported by <code>kubeadm</code>?</p></li>
  </ol>