func KubeadmConfig()

in kinder/pkg/cluster/manager/actions/kubeadm-config.go [59:135]
54 lines of code
9 McCabe index (conditional complexity)

func KubeadmConfig(c *status.Cluster, kubeadmConfigVersion string, copyCertsMode CopyCertsMode, discoveryMode DiscoveryMode, featureGate string, nodes ...*status.Node) error {
	cp1 := c.BootstrapControlPlane()

	// get installed kubernetes version from the node image
	kubeVersion, err := cp1.KubeVersion()
	if err != nil {
		return errors.Wrap(err, "failed to get kubernetes version from node")
	}

	// gets the IP of the bootstrap control plane node
	controlPlaneIP, controlPlaneIPV6, err := c.BootstrapControlPlane().IP()
	if err != nil {
		return errors.Wrapf(err, "failed to get IP for node: %s", c.BootstrapControlPlane().Name())
	}

	// get the control plane endpoint, in case the cluster has an external load balancer in
	// front of the control-plane nodes
	controlPlaneEndpoint, controlPlaneEndpointIPv6, ControlPlanePort, err := getControlPlaneAddress(c)
	if err != nil {
		return err
	}

	// configure the right protocol addresses
	if c.Settings.IPFamily == status.IPv6Family {
		controlPlaneIP = controlPlaneIPV6
		controlPlaneEndpoint = controlPlaneEndpointIPv6
	}

	featureGateName := ""
	featureGateValue := ""
	// We remove the leading and trailing double or single quotes because the
	// feature-gate could be set as
	// --kubeadm-feature-gate="RootlessControlPlane=true" or
	// --kubeadm-feature-gate='RootlessControlPlane=true', so the value
	// of featureGate string would be "\"RootlessControlPlane=true"\" or "RootlessControlPlane=true'" respectively.
	// Once we trim the value double or single quotes the value will be "RootlessControlPlane=true".
	trimmedFeatureGate := strings.Trim(featureGate, "\"'")
	if len(trimmedFeatureGate) > 0 {
		split := strings.Split(trimmedFeatureGate, "=")
		if len(split) != 2 {
			return errors.New("feature gate must be formatted as 'key=value'")
		}
		featureGateName = split[0]
		featureGateValue = split[1]
	}

	// create configData with all the configurations supported by the kubeadm config template implemented in kind
	configData := kubeadm.ConfigData{
		ClusterName:          c.Name(),
		KubernetesVersion:    kubeVersion,
		ControlPlaneEndpoint: fmt.Sprintf("%s:%d", controlPlaneEndpoint, ControlPlanePort),
		APIBindPort:          constants.APIServerPort,
		APIServerAddress:     controlPlaneIP,
		Token:                constants.Token,
		PodSubnet:            "192.168.0.0/16", // default for kindnet
		ControlPlane:         true,
		IPv6:                 c.Settings.IPFamily == status.IPv6Family,
		FeatureGateName:      featureGateName,
		FeatureGateValue:     featureGateValue,
	}

	// create configOptions with all the kinder flags that impact on the kubeadm config generation
	configOptions := kubeadmConfigOptions{
		configVersion: kubeadmConfigVersion,
		copyCertsMode: copyCertsMode,
		discoveryMode: discoveryMode,
	}

	// writs the kubeadm config file on all the K8s nodes.
	for _, node := range nodes {
		if err := writeKubeadmConfig(c, node, configData, configOptions); err != nil {
			return err
		}
	}

	return nil
}