ipallocator

Documentation

Overview

package ipallocator manages allocation of IP addresses from a network range. Modified from https://github.com/kubernetes/kubernetes/blob/v1.17.9/pkg/registry/core/service/ipallocator/allocator.go

Index

• Variables
• func GetIndexedIP(subnet *net.IPNet, index int) (net.IP, error)
• func RangeSize(subnet *net.IPNet) int64
• type ErrNotInRange
  • func (e *ErrNotInRange) Error() string
• type Range
  • func NewAllocatorCIDRRange(cidr *net.IPNet) *Range
  • func (r *Range) Allocate(ip net.IP) error
  • func (r *Range) AllocateNext() (net.IP, error)
  • func (r *Range) CIDR() net.IPNet
  • func (r *Range) Free() int
  • func (r *Range) Has(ip net.IP) bool
  • func (r *Range) Release(ip net.IP) error
  • func (r *Range) Used() int

Variables

var (
	// ErrFull indicates a range is full error
	ErrFull = errors.New("range is full")
	// ErrAllocated indicates an IP already allocated error
	ErrAllocated = errors.New("provided IP is already allocated")
	// ErrMismatchedNetwork indicates a mismatched network error
	ErrMismatchedNetwork = errors.New("the provided network does not match the current range")
)

Functions

func GetIndexedIP

func GetIndexedIP(subnet *net.IPNet, index int) (net.IP, error)

GetIndexedIP returns a net.IP that is subnet.IP + index in the contiguous IP space.

func RangeSize

func RangeSize(subnet *net.IPNet) int64

RangeSize returns the size of a range in valid addresses.

Types

type ErrNotInRange

type ErrNotInRange struct {
	ValidRange string
}

func (*ErrNotInRange) Error

func (e *ErrNotInRange) Error() string

type Range

type Range struct {
	// contains filtered or unexported fields
}

Range is a contiguous block of IPs that can be allocated atomically.

The internal structure of the range is:

For CIDR 10.0.0.0/24
254 addresses usable out of 256 total (minus base and broadcast IPs)
  The number of usable addresses is r.max

CIDR base IP          CIDR broadcast IP
10.0.0.0                     10.0.0.255
|                                     |
0 1 2 3 4 5 ...         ... 253 254 255
  |                              |
r.base                     r.base + r.max
  |                              |
offset #0 of r.allocated   last offset of r.allocated

func NewAllocatorCIDRRange

func NewAllocatorCIDRRange(cidr *net.IPNet) *Range

NewAllocatorCIDRRange creates a Range over a net.IPNet backed by in-memory store.

func (*Range) Allocate

func (r *Range) Allocate(ip net.IP) error

Allocate attempts to reserve the provided IP. ErrNotInRange or ErrAllocated will be returned if the IP is not valid for this range or has already been reserved. ErrFull will be returned if there are no addresses left.

func (*Range) AllocateNext

func (r *Range) AllocateNext() (net.IP, error)

AllocateNext reserves one of the IPs from the pool. ErrFull may be returned if there are no addresses left.

func (*Range) CIDR

func (r *Range) CIDR() net.IPNet

CIDR returns the CIDR covered by the range.

func (*Range) Free

func (r *Range) Free() int

Free returns the count of IP addresses left in the range.

func (*Range) Has

func (r *Range) Has(ip net.IP) bool

Has returns true if the provided IP is already allocated and a call to Allocate(ip) would fail with ErrAllocated.

func (*Range) Release

func (r *Range) Release(ip net.IP) error

Release releases the IP back to the pool. Releasing an unallocated IP or an IP out of the range is a no-op and returns no error.

func (*Range) Used

func (r *Range) Used() int

Used returns the count of IP addresses used in the range.