Deploy a Production Ready Kubernetes Cluster

Ansible

Python dependencies

pip install netaddr
pip install jmespath

Usage

# provison cluster
ansible-playbook -i ./inventory/visoftsolutions/inventory.ini  --become cluster.yml

# reset cluster
ansible-playbook -i ./inventory/visoftsolutions/inventory.ini  --become reset.yml

Configuration

In order to modify cluster provision setup go to:

cd ./inventory/visoftsolutions/

# vim inventory.ini
# checkout group_vars/all & group_vars/k8s_cluster

Documents

• Requirements
• Kubespray vs ...
• Getting started
• Setting up your first cluster
• Ansible inventory and tags
• Integration with existing ansible repo
• Deployment data variables
• DNS stack
• HA mode
• Network plugins
• Vagrant install
• Flatcar Container Linux bootstrap
• Fedora CoreOS bootstrap
• Debian Jessie setup
• openSUSE setup
• Downloaded artifacts
• Cloud providers
• OpenStack
• AWS
• Azure
• vSphere
• Equinix Metal
• Large deployments
• Adding/replacing a node
• Upgrades basics
• Air-Gap installation
• NTP
• Hardening
• Mirror
• Roadmap

Supported Linux Distributions

• Flatcar Container Linux by Kinvolk
• Debian Bookworm, Bullseye, Buster
• Ubuntu 20.04, 22.04
• CentOS/RHEL 7, 8, 9
• Fedora 37, 38
• Fedora CoreOS (see fcos Note)
• openSUSE Leap 15.x/Tumbleweed
• Oracle Linux 7, 8, 9
• Alma Linux 8, 9
• Rocky Linux 8, 9
• Kylin Linux Advanced Server V10 (experimental: see kylin linux notes)
• Amazon Linux 2 (experimental: see amazon linux notes)
• UOS Linux (experimental: see uos linux notes)
• openEuler (experimental: see openEuler notes)

Note: Upstart/SysV init based OS types are not supported.

Supported Components

• Core
  • kubernetes v1.28.2
  • etcd v3.5.7
  • docker v20.10 (see note)
  • containerd v1.7.6
  • cri-o v1.27 (experimental: see CRI-O Note. Only on fedora, ubuntu and centos based OS)
• Network Plugin
  • cni-plugins v1.2.0
  • calico v3.26.1
  • cilium v1.13.4
  • flannel v0.22.0
  • kube-ovn v1.11.5
  • kube-router v1.5.1
  • multus v3.8
  • weave v2.8.1
  • kube-vip v0.5.12
• Application
  • cert-manager v1.11.1
  • coredns v1.10.1
  • ingress-nginx v1.8.1
  • krew v0.4.4
  • argocd v2.8.0
  • helm v3.12.3
  • metallb v0.13.9
  • registry v2.8.1
• Storage Plugin
  • cephfs-provisioner v2.1.0-k8s1.11
  • rbd-provisioner v2.1.1-k8s1.11
  • aws-ebs-csi-plugin v0.5.0
  • azure-csi-plugin v1.10.0
  • cinder-csi-plugin v1.22.0
  • gcp-pd-csi-plugin v1.9.2
  • local-path-provisioner v0.0.24
  • local-volume-provisioner v2.5.0

Container Runtime Notes

• Supported Docker versions are 18.09, 19.03, 20.10, 23.0 and 24.0. The recommended Docker version is 20.10 (except on Debian bookworm which without supporting for 20.10 and below any more). Kubelet might break on docker's non-standard version numbering (it no longer uses semantic versioning). To ensure auto-updates don't break your cluster look into e.g. the YUM versionlock plugin or apt pin).
• The cri-o version should be aligned with the respective kubernetes version (i.e. kube_version=1.20.x, crio_version=1.20)

Requirements

• Minimum required version of Kubernetes is v1.26
• Ansible v2.14+, Jinja 2.11+ and python-netaddr is installed on the machine that will run Ansible commands
• The target servers must have access to the Internet in order to pull docker images. Otherwise, additional configuration is required (See Offline Environment)
• The target servers are configured to allow IPv4 forwarding.
• If using IPv6 for pods and services, the target servers are configured to allow IPv6 forwarding.
• The firewalls are not managed, you'll need to implement your own rules the way you used to. in order to avoid any issue during deployment you should disable your firewall.
• If kubespray is run from non-root user account, correct privilege escalation method should be configured in the target servers. Then the ansible_become flag or command parameters --become or -b should be specified.

Hardware: These limits are safeguarded by Kubespray. Actual requirements for your workload can differ. For a sizing guide go to the Building Large Clusters guide.

• Master
  • Memory: 1500 MB
• Node
  • Memory: 1024 MB

Network Plugins

You can choose among ten network plugins. (default: calico, except Vagrant uses flannel)

• flannel: gre/vxlan (layer 2) networking.

• Calico is a networking and network policy provider. Calico supports a flexible set of networking options designed to give you the most efficient networking across a range of situations, including non-overlay and overlay networks, with or without BGP. Calico uses the same engine to enforce network policy for hosts, pods, and (if using Istio and Envoy) applications at the service mesh layer.

• cilium: layer 3/4 networking (as well as layer 7 to protect and secure application protocols), supports dynamic insertion of BPF bytecode into the Linux kernel to implement security services, networking and visibility logic.

• weave: Weave is a lightweight container overlay network that doesn't require an external K/V database cluster. (Please refer to weave troubleshooting documentation).

• kube-ovn: Kube-OVN integrates the OVN-based Network Virtualization with Kubernetes. It offers an advanced Container Network Fabric for Enterprises.

• kube-router: Kube-router is a L3 CNI for Kubernetes networking aiming to provide operational simplicity and high performance: it uses IPVS to provide Kube Services Proxy (if setup to replace kube-proxy), iptables for network policies, and BGP for ods L3 networking (with optionally BGP peering with out-of-cluster BGP peers). It can also optionally advertise routes to Kubernetes cluster Pods CIDRs, ClusterIPs, ExternalIPs and LoadBalancerIPs.

• macvlan: Macvlan is a Linux network driver. Pods have their own unique Mac and Ip address, connected directly the physical (layer 2) network.

• multus: Multus is a meta CNI plugin that provides multiple network interface support to pods. For each interface Multus delegates CNI calls to secondary CNI plugins such as Calico, macvlan, etc.

• custom_cni : You can specify some manifests that will be applied to the clusters to bring you own CNI and use non-supported ones by Kubespray. See tests/files/custom_cni/README.md and tests/files/custom_cni/values.yamlfor an example with a CNI provided by a Helm Chart.

The network plugin to use is defined by the variable kube_network_plugin. There is also an option to leverage built-in cloud provider networking instead. See also Network checker.

Ingress Plugins

• nginx: the NGINX Ingress Controller.

• metallb: the MetalLB bare-metal service LoadBalancer provider.

Community docs and resources

• kubernetes.io/docs/setup/production-environment/tools/kubespray/
• kubespray, monitoring and logging by @gregbkr
• Deploy Kubernetes w/ Ansible & Terraform by @rsmitty
• Deploy a Kubernetes Cluster with Kubespray (video)

Tools and projects on top of Kubespray

• Digital Rebar Provision
• Terraform Contrib
• Kubean

CI Tests

CI/end-to-end tests sponsored by: CNCF, Equinix Metal, OVHcloud, ELASTX.

See the test matrix for details.