<p>There's a kubernetes cluster that was created by kops 
and when running <code>kops validate</code> this is the output:</p>

<pre><code>    INSTANCE GROUPS
NAME            ROLE    MACHINETYPE MIN MAX SUBNETS
master-us-east-1a   Master  m4.xlarge   1   1   us-east-1a
nodes           Node    c4.2xlarge  1   75  us-east-1a

NODE STATUS
NAME                ROLE    READY
ip-172-20-59-93.ec2.internal    master  False

VALIDATION ERRORS
KIND    NAME                MESSAGE
Machine i-0a44bbdd18c86e846     machine "i-0a44bbdd18c86e846" has not yet joined cluster
Machine i-0d3302056f3dfeef0     machine "i-0d3302056f3dfeef0" has not yet joined cluster
Machine i-0d6199876b91962f4     machine "i-0d6199876b91962f4" has not yet joined cluster
Node    ip-172-20-59-93.ec2.internal    master "ip-172-20-59-93.ec2.internal" is not ready

Validation Failed
</code></pre>

<p>How I can recover this cluster? The s3 files for this cluster are available.</p>

<p>The etcd volumes show status as "in-use"</p>

<p><a href="https://i.stack.imgur.com/s26kT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/s26kT.png" alt="screenshot"></a></p>

<p>kops stores the state of your cluster in S3.</p>

<ol>
<li>Find the bucket where the state is stored</li>
<li>Set <code>export KOPS_STATE_STORE=s3://your-k8s-state-store</code></li>
<li>Run <code>kops update cluster</code></li>
<li>If that fails. </li>
<li>Terminate all your instances related to the cluster</li>
<li>Run <code>kops create cluster</code></li>
</ol>

<p>Note that the internal state of your cluster is not in S3 but in etcd. The answer here has more details about this topic and also how to backup/restore etcd: <a href="https://stackoverflow.com/questions/51408546/how-to-restore-kubernetes-cluster-using-kops">How to restore kubernetes cluster using kops?</a></p>
