kubernetes-coreos-do

Walkthrough for setup Kubernetes on CoreOS on DigitalOcean.

Create Master Instance

1. Create a new droplet via DO interface, and choose following options
2. Droplet Hostname: master
3. Select Size: Any
4. Select Region: Any with private networking support
5. Available Settings: "Private Networking", "Enable User Data"
6. Put cloud-config to user data textarea
7. Select Image: CoreOS (stable)
8. Choose you SSH key
9. Press a "Create a Droplet" button

Prepare cloud-config for node (minion) Instance:

When the droplet will be created, login to system:

ssh core@%MASTER_DROPLET_EXTERNAL_IP%

Take and remember internal ip address (Note: if you use other cloud provider, network interface may be different from eth1, if is true, you also have to change it in all cloud-configs):

echo $(ip addr | grep inet | grep eth1 | grep global | awk '{print $2}' | sed -e 's/\/.*$//')

Replace all %MASTER_IP% placeholders in node cloud-config to the master ip.

Create node (minion) Instance

Create a new droplet via DO interface, and choose following options

1. Droplet Hostname: node-001
2. Select Size: Anyone you want
3. Select Region: Must be same as the master node
4. Available Settings: "Private Networking", "Enable User Data"
5. Put your changed cloud-config with MASTER IP to user data textarea
6. Select Image: CoreOS (stable)
7. Choose you SSH key
8. Press a "Create a Droplet" button

Completion

Login to your master instance:

ssh core@%MASTER_DROPLET_EXTERNAL_IP%

Download Kubectl:

sudo /usr/bin/wget -N -P /opt/bin https://storage.googleapis.com/kubernetes-release/release/v0.15.0/bin/linux/amd64/kubectl
sudo chmod +x /opt/bin/kubectl 

Check whether the all your nodes registered in Kubernetes

/opt/bin/kubectl get nodes