Cluster

apiVersion: kubeadm.k8s.io/v1beta3
kind: ClusterConfiguration

https://github.com/kubernetes/kubernetes/blob/master/cmd/kubeadm/app/apis/kubeadm/v1beta3/types.go

// ClusterConfiguration contains cluster-wide configuration for a kubeadm cluster
type ClusterConfiguration struct {
	metav1.TypeMeta `json:",inline"`

	// Etcd holds configuration for etcd.
	// +optional
	Etcd Etcd `json:"etcd,omitempty"`

	// Networking holds configuration for the networking topology of the cluster.
	// +optional
	Networking Networking `json:"networking,omitempty"`

	// KubernetesVersion is the target version of the control plane.
	// +optional
	KubernetesVersion string `json:"kubernetesVersion,omitempty"`

	// ControlPlaneEndpoint sets a stable IP address or DNS name for the control plane; it
	// can be a valid IP address or a RFC-1123 DNS subdomain, both with optional TCP port.
	// In case the ControlPlaneEndpoint is not specified, the AdvertiseAddress + BindPort
	// are used; in case the ControlPlaneEndpoint is specified but without a TCP port,
	// the BindPort is used.
	// Possible usages are:
	// e.g. In a cluster with more than one control plane instances, this field should be
	// assigned the address of the external load balancer in front of the
	// control plane instances.
	// e.g.  in environments with enforced node recycling, the ControlPlaneEndpoint
	// could be used for assigning a stable DNS to the control plane.
	// +optional
	ControlPlaneEndpoint string `json:"controlPlaneEndpoint,omitempty"`

	// APIServer contains extra settings for the API server control plane component
	// +optional
	APIServer APIServer `json:"apiServer,omitempty"`

	// ControllerManager contains extra settings for the controller manager control plane component
	// +optional
	ControllerManager ControlPlaneComponent `json:"controllerManager,omitempty"`

	// Scheduler contains extra settings for the scheduler control plane component
	// +optional
	Scheduler ControlPlaneComponent `json:"scheduler,omitempty"`

	// DNS defines the options for the DNS add-on installed in the cluster.
	// +optional
	DNS DNS `json:"dns,omitempty"`

	// CertificatesDir specifies where to store or look for all required certificates.
	// +optional
	CertificatesDir string `json:"certificatesDir,omitempty"`

	// ImageRepository sets the container registry to pull images from.
	// If empty, `k8s.gcr.io` will be used by default; in case of kubernetes version is a CI build (kubernetes version starts with `ci/` or `ci-cross/`)
	// `gcr.io/k8s-staging-ci-images` will be used as a default for control plane components and for kube-proxy, while `k8s.gcr.io`
	// will be used for all the other images.
	// +optional
	ImageRepository string `json:"imageRepository,omitempty"`

	// FeatureGates enabled by the user.
	// +optional
	FeatureGates map[string]bool `json:"featureGates,omitempty"`

	// The cluster name
	// +optional
	ClusterName string `json:"clusterName,omitempty"`
}

// Etcd contains elements describing Etcd configuration.
type Etcd struct {

	// Local provides configuration knobs for configuring the local etcd instance
	// Local and External are mutually exclusive
	// +optional
	Local *LocalEtcd `json:"local,omitempty"`

	// External describes how to connect to an external etcd cluster
	// Local and External are mutually exclusive
	// +optional
	External *ExternalEtcd `json:"external,omitempty"`
}

// LocalEtcd describes that kubeadm should run an etcd cluster locally
type LocalEtcd struct {
	// ImageMeta allows to customize the container used for etcd
	ImageMeta `json:",inline"`

	// DataDir is the directory etcd will place its data.
	// Defaults to "/var/lib/etcd".
	DataDir string `json:"dataDir"`

	// ExtraArgs are extra arguments provided to the etcd binary
	// when run inside a static pod.
	// A key in this map is the flag name as it appears on the
	// command line except without leading dash(es).
	// +optional
	ExtraArgs map[string]string `json:"extraArgs,omitempty"`

	// ServerCertSANs sets extra Subject Alternative Names for the etcd server signing cert.
	// +optional
	ServerCertSANs []string `json:"serverCertSANs,omitempty"`
	// PeerCertSANs sets extra Subject Alternative Names for the etcd peer signing cert.
	// +optional
	PeerCertSANs []string `json:"peerCertSANs,omitempty"`
}

// ExternalEtcd describes an external etcd cluster.
// Kubeadm has no knowledge of where certificate files live and they must be supplied.
type ExternalEtcd struct {
	// Endpoints of etcd members. Required for ExternalEtcd.
	Endpoints []string `json:"endpoints"`

	// CAFile is an SSL Certificate Authority file used to secure etcd communication.
	// Required if using a TLS connection.
	CAFile string `json:"caFile"`

	// CertFile is an SSL certification file used to secure etcd communication.
	// Required if using a TLS connection.
	CertFile string `json:"certFile"`

	// KeyFile is an SSL key file used to secure etcd communication.
	// Required if using a TLS connection.
	KeyFile string `json:"keyFile"`
}

// Networking contains elements describing cluster's networking configuration
type Networking struct {
	// ServiceSubnet is the subnet used by k8s services. Defaults to "10.96.0.0/12".
	// +optional
	ServiceSubnet string `json:"serviceSubnet,omitempty"`
	// PodSubnet is the subnet used by pods.
	// +optional
	PodSubnet string `json:"podSubnet,omitempty"`
	// DNSDomain is the dns domain used by k8s services. Defaults to "cluster.local".
	// +optional
	DNSDomain string `json:"dnsDomain,omitempty"`
}

// APIServer holds settings necessary for API server deployments in the cluster
type APIServer struct {
	ControlPlaneComponent `json:",inline"`

	// CertSANs sets extra Subject Alternative Names for the API Server signing cert.
	// +optional
	CertSANs []string `json:"certSANs,omitempty"`

	// TimeoutForControlPlane controls the timeout that we use for API server to appear
	// +optional
	TimeoutForControlPlane *metav1.Duration `json:"timeoutForControlPlane,omitempty"`
}

// ControlPlaneComponent holds settings common to control plane component of the cluster
type ControlPlaneComponent struct {
	// ExtraArgs is an extra set of flags to pass to the control plane component.
	// A key in this map is the flag name as it appears on the
	// command line except without leading dash(es).
	// TODO: This is temporary and ideally we would like to switch all components to
	// use ComponentConfig + ConfigMaps.
	// +optional
	ExtraArgs map[string]string `json:"extraArgs,omitempty"`

	// ExtraVolumes is an extra set of host volumes, mounted to the control plane component.
	// +optional
	ExtraVolumes []HostPathMount `json:"extraVolumes,omitempty"`
}

// DNS defines the DNS addon that should be used in the cluster
type DNS struct {
	// ImageMeta allows to customize the image used for the DNS component
	ImageMeta `json:",inline"`
}

// HostPathMount contains elements describing volumes that are mounted from the
// host.
type HostPathMount struct {
	// Name of the volume inside the pod template.
	Name string `json:"name"`
	// HostPath is the path in the host that will be mounted inside
	// the pod.
	HostPath string `json:"hostPath"`
	// MountPath is the path inside the pod where hostPath will be mounted.
	MountPath string `json:"mountPath"`
	// ReadOnly controls write access to the volume
	// +optional
	ReadOnly bool `json:"readOnly,omitempty"`
	// PathType is the type of the HostPath.
	// +optional
	PathType corev1.HostPathType `json:"pathType,omitempty"`
}

// ImageMeta allows to customize the image used for components that are not
// originated from the Kubernetes/Kubernetes release process
type ImageMeta struct {
	// ImageRepository sets the container registry to pull images from.
	// if not set, the ImageRepository defined in ClusterConfiguration will be used instead.
	// +optional
	ImageRepository string `json:"imageRepository,omitempty"`

	// ImageTag allows to specify a tag for the image.
	// In case this value is set, kubeadm does not change automatically the version of the above components during upgrades.
	// +optional
	ImageTag string `json:"imageTag,omitempty"`

	//TODO: evaluate if we need also a ImageName based on user feedbacks
}