IPAM process is held by 3 main resources: Networks, Subnets and IPs. There is also a supplicant Network Counter resource that handles unique network IP accounting and acquisition.
All resources are sharing similar concepts in status representation.
Every resource has a state
, that may have Processing
, Finished
or Failed
value.
If resource has a Failed
state, Message
should contain an explanation why it wasn't processed correctly.
If resource has been processed successfully, i.e. precessing has been Finished
, Reserved
field will have a
corresponding operation result, ID for Network, CIDR for Subnet or IP addres for IP.
Network is a top level resource that identifies unique address space. It means that 2 different Networks may have clashing address zones, and, on the other hand, it is not possible to have matching addresses at the same subnet.
Main responsibilities of the Network resource are to handle address space integrity, account child subnets and supply networks with valid unique IDs corresponding to network technology.
Network is able to handle both IPv4 and IPv6 address spaces simultaneously.
A proper Network CR should be formed following the rules below.
apiVersion: ipam.metal.ironcore.dev/v1alpha1
kind: Network
metadata:
name: network-sample
spec:
# Description is a free text description for network
# Optional
# String
description: sample
# ID is a network identifier
# Optional, will be generated if not set
# Numeric string
# Valid values for VXLAN: from 100 to 2^24 (3 byte value)
# Valid values for GENEVE: from 100 to 2^24 (3 byte value)
# Valid values for MPLS: from 16 to +inf (composite of 20 bit labels)
id: "1000"
# Type is a type of technology used to organize network
# Optional, but required if ID is set
# String (enum)
# Valid values: VXLAN, GENEVE, MPLS
type: GENEVE
When network is in use, kubectl
is able to show its type, reserved ID and total amount of addresses in child subnets.
[user@localhost ~]$ kubectl get networks
NAME TYPE RESERVED IPV4 CAPACITY IPV6 CAPACITY DESCRIPTION STATE MESSAGE
network-sample MPLS 16 16777216 18446744073709551616 mpls net Finished
If there is a need to have more precise date on ranges' availability for the selected network, Network request status may be inspected. It contains a list of address ranges booked by subnets.
[user@localhost ~]$ kubectl describe network mpls-network-sample
Name: network-sample
Namespace: default
API Version: ipam.metal.ironcore.dev/v1alpha1
Kind: Network
Status:
ipv4Capacity: 16777216
ipv4Ranges:
10.0.0.0/8
ipv6Capacity: 18446744073709551616
ipv6Ranges:
fd34:5d8f:e75e:f3a2::/64
Reserved: 16
State: Finished
...
If an exact ID should be picked for the Network, a counter for the corresponding network technology may be checked.
[user@localhost ~]$ kubectl get networkcounters
NAME AGE
k8s-geneve-network-counter 6d
k8s-mpls-network-counter 6d
k8s-vxlan-network-counter 6d
Counter itself maintains ranges of vacant inclusive ID intervals. If interval has an Exact
field set, as in example,
it means that it has only one value in the interval. Interval may also have an open border, i.e. no Begin
or End
value; it means that there is no limitation on min/max value.
If Vacant
collection is empty, then there are no intervals left.
[user@localhost ~]$ kubectl describe networkcounter k8s-vxlan-network-counter
Name: k8s-vxlan-network-counter
Namespace: default
API Version: ipam.metal.ironcore.dev/v1alpha1
Kind: NetworkCounter
Spec:
Vacant:
Exact: 100
Begin: 102
End: 16777215
Examples:
- empty network;
- network with VXLAN ID request;
- network with GENEVE ID request;
- network with MPLS ID request.
Subnets are representing an IP address ranges in a CIDR format.
Subnets may be split into 2 categories by their relations:
- Top level Subnets. These Subnets don't have a parent Subnet, they may define any unoccupied CIDR in the Network. To allocate a top level Subnet, it should specify CIDR explicitly.
- Child Subnets. These Subnets have other Subnet as a parent, and their address range and region scope should be within the scope of a parent. For child Subnets it is also possible to specify required address ranges by capacity or netmask prefix bits (bits occupied by ones). In that case a first smallest subnet matching the criteria mey be picked.
Subnets may be also categorized by their regional affiliation:
- Multiregional - Subnet that has more than one Region specified.
- Regional - Subnet that has one region and multiple availability zones.
- Local - Subnet with one region and one availability zone.
Here is an explanation on how to setup the Subnet.
apiVersion: ipam.metal.ironcore.dev/v1alpha1
kind: Subnet
metadata:
name: subnet-sample
spec:
# CIDR describes an IP range for the subnet
# Required for top level subnets
# Optional for child subnets
# String
# Only and at least one of cidr, prefixBits, capacity should be set
# If parent subnet is set, should be within address range of parent subnet
cidr: "10.0.0.0/16"
# PrefixBits is an amount of ones (occupied bits) in netmask
# Optional
# Can not be set for top level subnet
# Number
# Only and at least one of cidr, prefixBits, capacity should be set
# Valid values: 0-128
# Usage will result in reservation of CIDR in address range of parent subnet
# First smallest vacant CIDR in parent address range will be picked for range withdrawal
prefixBits: 16
# Capacity is an amount of addresses required
# Optional
# Can not be set for top level subnet
# Numeric string
# Only and at least one of cidr, prefixBits, capacity should be set
# Valid values: from 1 to 2^128
# Usage will result in reservation of CIDR in address range of parent subnet
# Capacity will be ceiled to next power of 2, if it is not power of 2 itself
# First smallest vacant CIDR in parent address range will be picked for range withdrawal
capacity: "100"
# ParentSubnet refers to the parent network at the same namespace
# Optional
# Object
# Should refer an existing subnet resource
parentSubnet:
name: "ipv4-parent-cidr-subnet-sample"
# Network refers to the parent network at the same namespace
# Required
# Object
# Should refer an existing network resource
network:
name: network-sample
# Regions is a list of regions subnet is attached to
# Required
# Set of objects (uniqueness is defined by name)
# If parent subnet is set, should be a subset of parent's region set, including AZ sets in matching regions
regions:
# Name is a unique name of the region for subnet tree
# Required
# String
# Should meet DNS label rules
- name: euw
# AvailabilityZones is a list of availability zones subnet is attached to
# Required
# Set of strings
# If parent subnet is set, should be a subset of parent's az set in matching region
availabilityZones:
- a
- b
# Consumer is a reference to k8s resource IP would be bound to
# Optional
# Object with string fields
consumer:
apiVersion: ipam.metal.ironcore.dev/v1alpha1
kind: SampleReource
name: sample-resorce-name
Apart of the data specified in manifest, Subnet's status also contains its address capacity (count) and capacity left, that is total capacity, minus capacity of child Subnets and individual IPs allocated on that Subnet.
[user@localhost ~]$ kubectl get subnets
NAME PARENT SUBNET PARENT NETWORK RESERVED ADDRESS TYPE LOCALITY PREFIX BITS CAPACITY CAPACITY LEFT STATE MESSAGE
ipv4-child-bits-subnet-sample ipv4-parent-cidr-subnet-sample network-sample 10.1.0.0/16 IPv4 Regional 16 65536 65536 Finished
ipv4-child-capacity-subnet-sample ipv4-parent-cidr-subnet-sample network-sample 10.2.0.0/25 IPv4 Regional 25 128 128 Finished
ipv4-child-cidr-subnet-sample ipv4-parent-cidr-subnet-sample network-sample 10.0.0.0/16 IPv4 Regional 16 65536 65532 Finished
ipv4-parent-cidr-subnet-sample network-sample 10.0.0.0/8 IPv4 Regional 8 16777216 16646016 Finished
ipv6-child-bits-subnet-sample ipv6-parent-cidr-subnet-sample network-sample fd34:5d8f:e75e:f3a2:1000::/88 IPv6 Regional 88 1099511627776 1099511627776 Finished
ipv6-child-capacity-subnet-sample ipv6-parent-cidr-subnet-sample network-sample fd34:5d8f:e75e:f3a2:1000:100::/95 IPv6 Regional 95 8589934592 8589934592 Finished
ipv6-child-cidr-subnet-sample ipv6-parent-cidr-subnet-sample network-sample fd34:5d8f:e75e:f3a2::/68 IPv6 Regional 68 1152921504606846976 1152921504606846973 Finished
ipv6-parent-cidr-subnet-sample network-sample fd34:5d8f:e75e:f3a2::/64 IPv6 Regional 64 18446744073709551616 17293821461001142272 Finished
Vacant ranges left may be also checked with describe
method of kubectl
.
[user@localhost ~]$ kubectl describe subnet ipv4-parent-cidr-subnet-sample
Name: ipv4-parent-cidr-subnet-sample
Namespace: default
API Version: ipam.metal.ironcore.dev/v1alpha1
Kind: Subnet
Status:
Capacity: 16777216
Capacity Left: 16646016
Locality: Regional
Prefix Bits: 8
Reserved: 10.0.0.0/8
State: Finished
Type: IPv4
Vacant:
10.2.0.128/25
10.2.1.0/24
10.2.2.0/23
10.2.4.0/22
10.2.8.0/21
10.2.16.0/20
10.2.32.0/19
10.2.64.0/18
10.2.128.0/17
10.3.0.0/16
10.4.0.0/14
10.8.0.0/13
10.16.0.0/12
10.32.0.0/11
10.64.0.0/10
10.128.0.0/9
Examples:
- IPv4 parent (top level) subnet;
- IPv4 child subnet with CIDR set explicitly;
- IPv4 child subnet with CIDR requested by network prefix bits;
- IPv4 child subnet with CIDR requested by address capacity;
- IPv6 parent (top level) subnet;
- IPv6 child subnet with CIDR set explicitly;
- IPv6 child subnet with CIDR requested by network prefix bits;
- IPv6 child subnet with CIDR requested by address capacity;
IPs are basically individual addresses, and the may be also represented in a form of /32 or /128 CIDRs for IPv4 and IPv6 correspondingly.
IPs are always booked on specified Subnet as CIDRs, reducing their capacity.
IPs may or may not point to resource they are assigned to.
apiVersion: ipam.metal.ironcore.dev/v1alpha1
kind: Ip
metadata:
name: ip-sample
spec:
# Subnet is a reference to subnet where IP should be reserved
# Required
# Object
# Should refer to an existing subnet at the same namespace
subnet:
name: ipv4-child-cidr-subnet-sample
# Consumer is a reference to k8s resource IP would be bound to
# Optional
# Object with string fields
consumer:
apiVersion: ipam.metal.ironcore.dev/v1alpha1
kind: SampleReource
name: sample-resorce-name
# IP
# Optional
# String
# If not specified, IP from the first smallest vacant CIDR of referred subnet would be picked
ip: 10.0.0.2
Sample output for the kubectl
.
[user@localhost ~]$ kubectl get ips
NAME IP SUBNET RESOURCE GROUP RESOURCE KIND RESOURCE NAME STATE MESSAGE
ipv4-ip-ip-sample 10.0.0.1 ipv4-child-cidr-subnet-sample Finished
ipv4-ip-sample 10.0.0.3 ipv4-child-cidr-subnet-sample Finished
ipv4-resource-and-ip-ip-sample 10.0.0.2 ipv4-child-cidr-subnet-sample ipam.metal.ironcore.dev/v1alpha1 NetworkCounter referred-networkcounter-sample Finished
ipv4-resource-ip-sample 10.0.0.0 ipv4-child-cidr-subnet-sample ipam.metal.ironcore.dev/v1alpha1 NetworkCounter referred-networkcounter-sample Finished
ipv6-ip-ip-sample fd34:5d8f:e75e:f3a2::1 ipv6-child-cidr-subnet-sample Finished
ipv6-ip-sample fd34:5d8f:e75e:f3a2::3 ipv6-child-cidr-subnet-sample Finished
ipv6-resource-and-ip-ip-sample fd34:5d8f:e75e:f3a2::2 ipv6-child-cidr-subnet-sample ipam.metal.ironcore.dev/v1alpha1 NetworkCounter referred-networkcounter-sample Finished
ipv6-resource-ip-sample fd34:5d8f:e75e:f3a2:: ipv6-child-cidr-subnet-sample ipam.metal.ironcore.dev/v1alpha1 NetworkCounter referred-networkcounter-sample Finished
IPs status is pretty simple and does not provide any additional info.
Name: ipv4-ip-ip-sample
Namespace: default
API Version: ipam.metal.ironcore.dev/v1alpha1
Kind: Ip
Status:
Reserved: 10.0.0.1
State: Finished
...
Examples:
- IPv4 IP request;
- IPv4 IP request with reference to related resource;
- IPv4 IP request with IP set explicitly;
- IPv4 IP request with reference to related resource and IP set explicitly;
- IPv6 IP request;
- IPv6 IP request with reference to related resource;
- IPv6 IP request with IP set explicitly;
- IPv6 IP request with reference to related resource and IP set explicitly;