Templating

Values Templating

KKP treats each valuesBlock string value or values map in an application installation resource as a Go template, so it is possible to inject user-cluster related information into applications at runtime. Please refer to the Go documentation for the exact templating syntax.

KKP injects an instance of the TemplateData struct into each template. The following Go snippet shows the available information:

// TemplateData is the root context injected into each application values.
type TemplateData struct {
	Cluster ClusterData
}

// ClusterData contains data related to the user cluster
// the application is rendered for.
type ClusterData struct {
	Name string
	// HumanReadableName is the user-specified cluster name.
	HumanReadableName string
	// OwnerEmail is the owner's e-mail address.
	OwnerEmail string
	// ClusterAddress stores access and address information of a cluster.
	Address kubermaticv1.ClusterAddress
	// Version is the exact current cluster version.
	Version string
	// MajorMinorVersion is a shortcut for common testing on "Major.Minor" on the
	// current cluster version.
	MajorMinorVersion string
	// AutoscalerVersion is the tag which should be used for the cluster autoscaler
	AutoscalerVersion string
}

// ClusterAddress stores access and address information of a cluster.
type ClusterAddress struct {
	// URL under which the Apiserver is available
	// +optional
	URL string `json:"url"`
	// Port is the port the API server listens on
	// +optional
	Port int32 `json:"port"`
	// ExternalName is the DNS name for this cluster
	// +optional
	ExternalName string `json:"externalName"`
	// InternalName is the seed cluster internal absolute DNS name to the API server
	// +optional
	InternalName string `json:"internalURL"`
	// AdminToken is the token for the kubeconfig, the user can download
	// +optional
	AdminToken string `json:"adminToken"`
	// IP is the external IP under which the apiserver is available
	// +optional
	IP string `json:"ip"`
	// APIServerExternalAddress is the external address of the API server (IP or DNS name)
	// This field is populated only when the API server service is of type LoadBalancer. If set, this address will be used in the
	// kubeconfig for the user cluster that can be downloaded from the KKP UI.
	// +optional
	APIServerExternalAddress string `json:"apiServerExternalAddress,omitempty"`
}