Creating a Kubernetes cluster using Kops requires a top-level domain or a sub domain and setting up Route 53 hosted zones. This domain allows the worker nodes to discover the master and the master to discover all the etcd servers. This is also needed for kubectl to be able to talk directly with the master. This worked well but an additional hassle for the developers.

Kops 1.6.2 adds an experimental support for gossip-based, uses Weave Mesh, discovery of nodes. This makes the process of setting up Kubernetes cluster using Kops DNS-free, and much more simplified.

Let’s take a look!

1. Install or upgrade kops:
   
   brew upgrade kops

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   brew upgrade kops

2. Check the version:
   
   ~ $ kops version Version 1.6.2

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   ~ $ kops version Version 1.6.2

3. Create an S3 bucket as “state store”:
   
   aws s3api create-bucket --bucket kubernetes-arungupta-me export KOPS_STATE_STORE=s3://kubernetes-arungupta-me

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   aws s3api create-bucket --bucket kubernetes-arungupta-me export KOPS_STATE_STORE=s3://kubernetes-arungupta-me

4. Create a Kubernetes cluster:
   
   kops create cluster cluster.k8s.local --zones us-east-1a --yes

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   kops create cluster cluster.k8s.local --zones us-east-1a --yes

   It shows the output as:
   
   I0622 16:52:07.494558 83656 create_cluster.go:655] Inferred --cloud=aws from zone "us-east-1a" I0622 16:52:07.495012 83656 create_cluster.go:841] Using SSH public key: /Users/argu/.ssh/id_rsa.pub I0622 16:52:08.540445 83656 subnets.go:183] Assigned CIDR 172.20.32.0/19 to subnet us-east-1a I0622 16:52:16.327523 83656 apply_cluster.go:396] Gossip DNS: skipping DNS validation I0622 16:52:25.539755 83656 executor.go:91] Tasks: 0 done / 67 total; 32 can run I0622 16:52:29.843320 83656 vfs_castore.go:422] Issuing new certificate: "kubecfg" I0622 16:52:30.108046 83656 vfs_castore.go:422] Issuing new certificate: "kubelet" I0622 16:52:30.139629 83656 vfs_castore.go:422] Issuing new certificate: "kube-scheduler" I0622 16:52:31.072229 83656 vfs_castore.go:422] Issuing new certificate: "kube-proxy" I0622 16:52:31.082560 83656 vfs_castore.go:422] Issuing new certificate: "kube-controller-manager" I0622 16:52:31.579158 83656 vfs_castore.go:422] Issuing new certificate: "kops" I0622 16:52:32.742807 83656 executor.go:91] Tasks: 32 done / 67 total; 13 can run I0622 16:52:43.057189 83656 executor.go:91] Tasks: 45 done / 67 total; 18 can run I0622 16:52:50.047375 83656 executor.go:91] Tasks: 63 done / 67 total; 3 can run I0622 16:53:02.047610 83656 vfs_castore.go:422] Issuing new certificate: "master" I0622 16:53:03.027007 83656 executor.go:91] Tasks: 66 done / 67 total; 1 can run I0622 16:53:04.197637 83656 executor.go:91] Tasks: 67 done / 67 total; 0 can run I0622 16:53:04.884362 83656 update_cluster.go:229] Exporting kubecfg for cluster Kops has set your kubectl context to cluster.k8s.local Cluster is starting. It should be ready in a few minutes. Suggestions: * validate cluster: kops validate cluster * list nodes: kubectl get nodes --show-labels * ssh to the master: ssh -i ~/.ssh/id_rsa admin@api.cluster.k8s.local The admin user is specific to Debian. If not using Debian please use the appropriate user based on your OS. * read about installing addons: https://github.com/kubernetes/kops/blob/master/docs/addons.md

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   I0622 16:52:07.494558   83656 create_cluster.go:655] Inferred --cloud=aws from zone "us-east-1a" I0622 16:52:07.495012   83656 create_cluster.go:841] Using SSH public key: /Users/argu/.ssh/id_rsa.pub I0622 16:52:08.540445   83656 subnets.go:183] Assigned CIDR 172.20.32.0/19 to subnet us-east-1a I0622 16:52:16.327523   83656 apply_cluster.go:396] Gossip DNS: skipping DNS validation I0622 16:52:25.539755   83656 executor.go:91] Tasks: 0 done / 67 total; 32 can run I0622 16:52:29.843320   83656 vfs_castore.go:422] Issuing new certificate: "kubecfg" I0622 16:52:30.108046   83656 vfs_castore.go:422] Issuing new certificate: "kubelet" I0622 16:52:30.139629   83656 vfs_castore.go:422] Issuing new certificate: "kube-scheduler" I0622 16:52:31.072229   83656 vfs_castore.go:422] Issuing new certificate: "kube-proxy" I0622 16:52:31.082560   83656 vfs_castore.go:422] Issuing new certificate: "kube-controller-manager" I0622 16:52:31.579158   83656 vfs_castore.go:422] Issuing new certificate: "kops" I0622 16:52:32.742807   83656 executor.go:91] Tasks: 32 done / 67 total; 13 can run I0622 16:52:43.057189   83656 executor.go:91] Tasks: 45 done / 67 total; 18 can run I0622 16:52:50.047375   83656 executor.go:91] Tasks: 63 done / 67 total; 3 can run I0622 16:53:02.047610   83656 vfs_castore.go:422] Issuing new certificate: "master" I0622 16:53:03.027007   83656 executor.go:91] Tasks: 66 done / 67 total; 1 can run I0622 16:53:04.197637   83656 executor.go:91] Tasks: 67 done / 67 total; 0 can run I0622 16:53:04.884362   83656 update_cluster.go:229] Exporting kubecfg for cluster Kops has set your kubectl context to cluster.k8s.local   Cluster is starting.  It should be ready in a few minutes.   Suggestions: * validate cluster: kops validate cluster * list nodes: kubectl get nodes --show-labels * ssh to the master: ssh -i ~/.ssh/id_rsa admin@api.cluster.k8s.local The admin user is specific to Debian. If not using Debian please use the appropriate user based on your OS. * read about installing addons: https://github.com/kubernetes/kops/blob/master/docs/addons.md

   Wait for a few minutes for the cluster to be created.
5. Validate the cluster:
   
   ~ $ kops validate cluster Using cluster from kubectl context: cluster.k8s.local Validating cluster cluster.k8s.local INSTANCE GROUPS NAME ROLE MACHINETYPE MIN MAX SUBNETS master-us-east-1a Master m3.medium 1 1 us-east-1a nodes Node t2.medium 2 2 us-east-1a NODE STATUS NAME ROLE READY ip-172-20-36-52.ec2.internal node True ip-172-20-38-117.ec2.internal master True ip-172-20-49-179.ec2.internal node True Your cluster cluster.k8s.local is ready

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   ~ $ kops validate cluster Using cluster from kubectl context: cluster.k8s.local   Validating cluster cluster.k8s.local   INSTANCE GROUPS NAME            ROLE    MACHINETYPE    MIN    MAX    SUBNETS master-us-east-1a    Master    m3.medium    1    1    us-east-1a nodes            Node    t2.medium    2    2    us-east-1a   NODE STATUS NAME                ROLE    READY ip-172-20-36-52.ec2.internal    node    True ip-172-20-38-117.ec2.internal    master    True ip-172-20-49-179.ec2.internal    node    True   Your cluster cluster.k8s.local is ready

6. Get the list of nodes using kubectl:
   
   ~ $ kubectl get nodes NAME STATUS AGE VERSION ip-172-20-36-52.ec2.internal Ready,node 4h v1.6.2 ip-172-20-38-117.ec2.internal Ready,master 4h v1.6.2 ip-172-20-49-179.ec2.internal Ready,node 4h v1.6.2

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   ~ $ kubectl get nodes NAME                            STATUS         AGE       VERSION ip-172-20-36-52.ec2.internal    Ready,node     4h        v1.6.2 ip-172-20-38-117.ec2.internal   Ready,master   4h        v1.6.2 ip-172-20-49-179.ec2.internal   Ready,node     4h        v1.6.2

7. Deleting a cluster is pretty straight forward as well:
   
   kops delete cluster cluster.k8s.local --yes

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   kops delete cluster cluster.k8s.local --yes

That’s it!

github.com/arun-gupta/kubernetes-java-sample provide several examples of getting started with Kubernetes.

File issues at github.com/kubernetes/kops/issues.