Installing Kubernetes On-premises/Cloud Providers with Kubespray
Overview
This quickstart helps to install a Kubernetes cluster hosted on GCE, Azure, OpenStack, AWS, or Baremetal with Kubespray.
Kubespray is a composition of Ansible playbooks, inventory, provisioning tools, and domain knowledge for generic OS/Kubernetes clusters configuration management tasks. Kubespray provides:
- a highly available cluster
- composable attributes
- support for most popular Linux distributions (CoreOS, Debian Jessie, Ubuntu 16.04, CentOS/RHEL 7, Fedora/CentOS Atomic)
- continuous integration tests
To choose a tool which best fits your use case, read this comparison to kubeadm and kops.
Creating a cluster
(1/5) Meet the underlay requirements
Provision servers with the following requirements:
Ansible v2.4(or newer)Jinja 2.9(or newer)python-netaddrinstalled on the machine that running Ansible commands- Target servers must have access to the Internet in order to pull docker images
- Target servers are configured to allow IPv4 forwarding
- Target servers have SSH connectivity ( tcp/22 ) directly to your nodes or through a bastion host/ssh jump box
- Target servers have a privileged user
- Your SSH key must be copied to all the servers that are part of your inventory
- Firewall rules configured properly to allow Ansible and Kubernetes components to communicate
- If using a cloud provider, you must have the appropriate credentials available and exported as environment variables
Kubespray provides the following utilities to help provision your environment:
(2/5) Compose an inventory file
After you provision your servers, create an inventory file for Ansible. You can do this manually or via a dynamic inventory script. For more information, see “Building your own inventory”.
(3/5) Plan your cluster deployment
Kubespray provides the ability to customize many aspects of the deployment:
- CNI (networking) plugins
- DNS configuration
- Choice of control plane: native/binary or containerized with docker or rkt)
- Component versions
- Calico route reflectors
- Component runtime options
- Certificate generation methods
Kubespray customizations can be made to a variable file. If you are just getting started with Kubespray, consider using the Kubespray defaults to deploy your cluster and explore Kubernetes.
(4/5) Deploy a Cluster
Next, deploy your cluster:
Cluster deployment using ansible-playbook.
ansible-playbook -i your/inventory/hosts.ini cluster.yml -b -v \
--private-key=~/.ssh/private_key
Large deployments (100+ nodes) may require specific adjustments for best results.
(5/5) Verify the deployment
Kubespray provides a way to verify inter-pod connectivity and DNS resolve with Netchecker. Netchecker ensures the netchecker-agents pods can resolve DNS requests and ping each over within the default namespace. Those pods mimic similar behavior of the rest of the workloads and serve as cluster health indicators.
Cluster operations
Kubespray provides additional playbooks to manage your cluster: scale and upgrade.
Scale your cluster
You can add worker nodes from your cluster by running the scale playbook. For more information, see “Adding nodes”. You can remove worker nodes from your cluster by running the remove-node playbook. For more information, see “Remove nodes”.
Upgrade your cluster
You can upgrade your cluster by running the upgrade-cluster playbook. For more information, see “Upgrades”.
What’s next
Check out planned work on Kubespray’s roadmap.
Cleanup
You can reset your nodes and wipe out all components installed with Kubespray via the reset playbook.
Caution: When running the reset playbook, be sure not to accidentally target your production cluster!
Feedback
- Slack Channel: #kubespray
- GitHub Issues