How to install Canonical Kubernetes with a custom bootstrap configuration

When creating a Canonical Kubernetes cluster that differs from the default configuration you can choose to use a custom bootstrap configuration. The CLI’s interactive mode or a custom bootstrap configuration file allow you to modify the configuration of the first node of your cluster.

Configuration options

Please consult the reference page for all of the available configuration options and their defaults.

Note

Most of these configuration options are set during the initial bootstrapping and cannot be modified afterward. Runtime changes may be unsupported and could require deploying a new cluster. Refer to the reference page to determine if an option allows later modifications.

Interactive mode

The interactive mode allows for the selection of the built-in features, the pod CIDR and the Service CIDR.

To bootstrap interactively, run:

sudo k8s bootstrap --timeout 10m --interactive

Here is an example custom configuration:

Which features would you like to enable? (network, dns, gateway, ingress, local-storage, load-balancer) [network, dns, gateway, local-storage]: network,ingress,dns
Please set the Pod CIDR: [10.1.0.0/16]: 10.1.0.0/16,fd01::/108
Please set the Service CIDR: [10.152.183.0/24]: 10.152.183.0/24,fd98::/108

The expected output shows your node’s ip that will differ from this example:

Bootstrapping the cluster. This may take a few seconds, please wait.
Bootstrapped a new Kubernetes cluster with node address "192.122.3.111:6400".
The node will be 'Ready' to host workloads after the CNI is deployed successfully.

Bootstrap configuration file

If your deployment requires a more fine-tuned configuration, use the bootstrap configuration file.

Note

When using the custom configuration file on bootstrap, all features including network, dns, gateway, ingress, load-balancer and local-storage are disabled by default.

For this example, create a custom bootstrap configuration file that enables the network feature:

cat <<EOF > bootstrap.yaml
cluster-config:
  network:
    enabled: true
EOF

Then, apply the bootstrap configuration file:

sudo k8s bootstrap --file /path/to/bootstrap.yaml

To verify any changes to the built-in features run:

sudo k8s status