Add StaticIPAllocation in Subnet spec

[heypnus]

The NSX operator will allow the customer to specify the property
subnetAdvancedConfig.staticIpAllocation.enabled for VPC Subnet in the Subnet CR.

If staticIPAllocation is not set explicitly in the Subnet CR, the static
IP pool allocation will be automatically enabled when the DHCP mode is DHCPDeactivated
or not set and disabled when the DHCP mode is DHCPServer or DHCPRelay. The NSX operator
will update the spec.subnetAdvancedConfig.staticIpAllocation.enabled with true of false.

The static IP pool allocation and DHCP mode cannot both be enabled simultaneously
in Subnet.

Testing done:

1. create Subnet with the following spec, the NSX Subnet can be created with
   subnet_dhcp_config.mode=DHCP_DEACTIVATED and advanced_config.static_ip_allocation.enabled=false.

spec:
  accessMode: Private
  advancedConfig:
    staticIPAllocation:
      enabled: false

2. create Subnet with the following spec, the NSX Subnet can be created with
   subnet_dhcp_config.mode=DHCP_DEACTIVATED and advanced_config.static_ip_allocation.enabled=true.

spec:
  accessMode: Private
  advancedConfig:
    staticIPAllocation:
      enabled: true

3. create Subnet with the following spec, the NSX Subnet can be created with
   .subnet_dhcp_config.mode=DHCP_SERVER and static_ip_allocation.enabled=false.

spec:
  accessMode: Private
  subnetDHCPConfig:
    mode: DHCPServer

check the Subnet CR, its spec is updated to

spec:
  accessMode: Private
  advancedConfig:
    connectivityState: Connected
    enableVLANExtension: false
    staticIPAllocation:
      enabled: false
  ipv4SubnetSize: 32
  subnetDHCPConfig:
    mode: DHCPServer
  vpcName: Project Quality:ns-sunq-01_76261cd3-26a7-4e96-97d5-3886c66f0fa1

4. create Subnet with the following spec, the NSX Subnet can be created with
   subnet_dhcp_config.mode=DHCP_DEACTIVATED and static_ip_allocation.enabled=true.

spec:
  accessMode: Private

check the Subnet CR, its spec is updated to

spec:
  accessMode: Private
  advancedConfig:
    connectivityState: Connected
    enableVLANExtension: false
    staticIPAllocation:
      enabled: true
  ipv4SubnetSize: 32
  subnetDHCPConfig: {}
  vpcName: Project Quality:ns-sunq-01_76261cd3-26a7-4e96-97d5-3886c66f0fa1

5. create Subnet with the following spec

spec:
  accessMode: Private
  advancedConfig:
    staticIPAllocation:
      enabled: true
  subnetDHCPConfig:
    mode: DHCPServer

the kubectl reports the following error:
The Subnet "subnet-debug-05" is invalid: spec: Invalid value: "object": Static IP pool allocation and Subnet DHCP configuration cannot both be enabled simultaneously in Subnet

[jianjuns]

Please change "subnet" to "Subnet" in the commit message and description.

[jianjuns]

What is the use case of exposing StaticIPAllocation in Subnet CRD? We need to support a case that a Subnet has neither DHCP or NSX IPAM enabled? @dantingl @lxiaopei

[dantingl]

What is the use case of exposing StaticIPAllocation in Subnet CRD? We need to support a case that a Subnet has neither DHCP or NSX IPAM enabled? @dantingl @lxiaopei

VKS has a requirement to not allocate IP for SubentPort, we plan to add StaticIPAllocation in Subnet CRD, so all ports would not get IP if StaticIPAllocation is false for DHCP_Deactivated Subnet.

[heypnus]

Please change "subnet" to "Subnet" in the commit message and description.

done

[jianjuns]

VKS has a requirement to not allocate IP for SubentPort, we plan to add StaticIPAllocation in Subnet CRD, so all ports would not get IP if StaticIPAllocation is false for DHCP_Deactivated Subnet.

I see. In NSX API, if StaticIPAllocation is false on a Subnet, a SubnetPort cannot request IP allocation from NSX IPAM? @dantingl

[heypnus]

VKS has a requirement to not allocate IP for SubentPort, we plan to add StaticIPAllocation in Subnet CRD, so all ports would not get IP if StaticIPAllocation is false for DHCP_Deactivated Subnet.

I see. In NSX API, if StaticIPAllocation is false on a Subnet, a SubnetPort cannot request IP allocation from NSX IPAM? @dantingl

Yes. For the NSX API behavior for the IP allocation request, I ever posted the verification results in the design doc, if the StaticIPAllocation is disabled, all port creation request with allocate_addresses=BOTH/IP_POOL failed (e.g. Apr 22, 2025, 3:20:00 PM : LogicalSwitch 8ab0b3d5-c7b1-4d19-8712-5e82b8d87b73 does not have IpPoolId needed by LogicalPort address allocation type Both.). For the VKS use case, you can refer to the testing done case 8 in commit message. The 3 port kinds(DHCP, IPAM, no IP) maps to case 6, 7, 8, I posted the port status for the reviewer to compare.

[dantingl]

LGTM

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 73.05%. Comparing base (1265b52) to head (ea62c01).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1119      +/-   ##
==========================================
+ Coverage   73.03%   73.05%   +0.01%     
==========================================
  Files         137      137              
  Lines       21668    21680      +12     
==========================================
+ Hits        15826    15838      +12     
  Misses       4847     4847              
  Partials      995      995              

Flag	Coverage Δ
unit-tests	73.05% <100.00%> (+0.01%)	⬆️

Files with missing lines	Coverage Δ
pkg/controllers/subnet/subnet_controller.go	68.63% <100.00%> (+0.29%)	⬆️
pkg/nsx/services/subnet/builder.go	88.88% <100.00%> (+0.13%)	⬆️
pkg/nsx/services/subnetport/builder.go	85.35% <100.00%> (+0.18%)	⬆️
pkg/nsx/services/subnetport/subnetport.go	86.12% <100.00%> (+0.61%)	⬆️
pkg/util/utils.go	83.12% <100.00%> (+0.43%)	⬆️

... and 1 file with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[heypnus]

/e2e

[dantingl]

Do we need to check whether subnetCR.Spec.AdvancedConfig is nil or not?

[heypnus]

We don't need because its data structure is not a pointer. In the other word, if I change this line to if subnetCR.Spec.AdvancedConfig != nil && subnetCR.Spec.AdvancedConfig.StaticIPAllocation.Enabled == nil {, the golang will report error invalid operation: subnetCR.Spec.AdvancedConfig != nil (mismatched types "github.com/vmware-tanzu/nsx-operator/pkg/apis/vpc/v1alpha1".SubnetAdvancedConfig and untyped nil)
And the test cases 3 and 4 already covered the case that AdvancedConfig is not set.