azure_config_network_range_getter.go

package ipam

import (
	"context"
	"net"
	"reflect"

	"github.com/giantswarm/microerror"
)

const (
	// minAllocatedVNetMaskBits is the maximum size of guest subnet i.e.
	// smaller number here -> larger subnet per guest cluster. For now anything
	// under 16 doesn't make sense in here.
	minAllocatedVNetMaskBits = 16
)

type AzureConfigNetworkRangeGetterConfig struct {
	InstallationNetworkRange            net.IPNet
	TenantClusterVirtualNetworkMaskBits int
}

// AzureConfigNetworkRangeGetter is NetworkRangeGetter implementation for
// AzureConfig.
type AzureConfigNetworkRangeGetter struct {
	installationNetworkRange        net.IPNet
	tenantClusterVirtualNetworkMask net.IPMask
}

func NewAzureConfigNetworkRangeGetter(config AzureConfigNetworkRangeGetterConfig) (*AzureConfigNetworkRangeGetter, error) {
	if reflect.DeepEqual(config.InstallationNetworkRange, net.IPNet{}) {
		return nil, microerror.Maskf(invalidConfigError, "%T.InstallationNetworkRange must not be empty", config)
	}
	if config.TenantClusterVirtualNetworkMaskBits < minAllocatedVNetMaskBits {
		return nil, microerror.Maskf(invalidConfigError, "%T.TenantClusterVirtualNetworkMaskBits (%d) must not be smaller than %d", config, config.TenantClusterVirtualNetworkMaskBits, minAllocatedVNetMaskBits)
	}

	g := AzureConfigNetworkRangeGetter{
		installationNetworkRange:        config.InstallationNetworkRange,
		tenantClusterVirtualNetworkMask: net.CIDRMask(config.TenantClusterVirtualNetworkMaskBits, 32),
	}

	return &g, nil
}

// GetParentNetworkRange gets the predefined installation network range, since the tenant cluster
// virtual network is getting its IP range from all available address ranges in the installation.
func (g *AzureConfigNetworkRangeGetter) GetParentNetworkRange(_ context.Context, _ interface{}) (net.IPNet, error) {
	return g.installationNetworkRange, nil
}

// GetRequiredIPMask returns an IP mask for tenant cluster virtual network.
func (g *AzureConfigNetworkRangeGetter) GetRequiredIPMask() net.IPMask {
	return g.tenantClusterVirtualNetworkMask
}