Auto fill ippool

[starbops]

IMPORTANT: Please do not create a Pull Request without creating an issue first.

Problem:

To successfully create the IPPool object, users must specify the pool range, i.e., the start and end IPs, and the DHCP server's IP. The reason why this is bad when it comes to user experience is that:

• Most of the time, users just want the whole subnet to be allocatable.
• Users don't give a dime about what the DHCP server's IP is.

Solution:

Implement a mutator to automatically add the missing fields (serverIP, start, and end). Also, if the serverIP or router is within the range consisting of start and end, mark it as RESERVED and make it not allocatable.

Related Issue:

harvester/harvester#5045

Test plan:

1. Install harvester-vm-dhcp-controller on the Harvester cluster

   helm upgrade --install harvester-vm-dhcp-controller ./chart --namespace=harvester-system
   

2. Create Cluster Network (ClusterNetwork), Network Config (VlanConfig), and VM Network (NAD) default/test-net

3. Create an IPPool object associated with the above-created VM Network

   cat <<EOF | kubectl apply -f -
   apiVersion: network.harvesterhci.io/v1alpha1
   kind: IPPool
   metadata:
     namespace: default
     name: test-net
   spec:
     networkName: default/test-net
     ipv4Config:
       cidr: 192.168.0.0/24
   

4. Check the IPPool's spec and status section, the following fields should be filled:

   • .spec.ipv4Config.serverIP
   • .spec.ipv4Config.pool.start
   • .spec.ipv4Config.pool.end

   For example:

   apiVersion: network.harvesterhci.io/v1alpha1
   kind: IPPool
   metadata:
     ...
     name: test-net
     namespace: default
   spec:
     ipv4Config:
       cidr: 192.168.0.0/24
       pool:
         end: 192.168.0.254
         start: 192.168.0.1
       serverIP: 192.168.0.1
     networkName: default/test-net
   status:
     agentPodRef:
       name: default-test-net-agent
       namespace: harvester-system
     conditions:
     - lastUpdateTime: "2024-01-29T13:00:23Z"
       status: "True"
       type: Registered
     - lastUpdateTime: "2024-01-29T13:00:23Z"
       status: "True"
       type: CacheReady
     - lastUpdateTime: "2024-01-29T13:00:37Z"
       status: "True"
       type: AgentReady
     - lastUpdateTime: "2024-01-29T13:00:23Z"
       status: "False"
       type: Stopped
     ipv4:
       allocated:
         192.168.0.1: RESERVED
       available: 253
       used: 0
     lastUpdate: "2024-01-29T13:00:23Z"
   

   Note that because the serverIP is within the pool range (from start to end), the IP must be marked as RESERVED under the .status.ipv4.allocated field.

[starbops]

Code conflicts are resolved.

[ibrokethecloud]

we update serverIP in this method, and currently the method signature makes this hard to ready. we should may be return a *string, and use nil/not nil to identify if it has been updated?

[ibrokethecloud]

we should change the method signature to make the pool object return more specific

[starbops]

@ibrokethecloud I've updated the method signatures to make them more explicit. PTAL, thanks!

[ibrokethecloud]

lgtm. thanks.

[bk201]

lgtm!