[WIP] subnetProvider

[helen-frank]

• LivenessProbe
• List
• ZonalSubnetsForLaunch
• UpdateInflightIPs

Dependencies: #11

type Provider interface {
	LivenessProbe(*http.Request) error
	List(context.Context, *v1.EC2NodeClass) ([]*ec2.Subnet, error)
	ZonalSubnetsForLaunch(context.Context, *v1.EC2NodeClass, []*cloudprovider.InstanceType, string) (map[string]*Subnet, error)
	UpdateInflightIPs(*ec2.CreateFleetInput, *ec2.CreateFleetOutput, []*cloudprovider.InstanceType, []*Subnet, string)
}

[daimaxiaxie]

This is somewhat different from AliCloud. The available IP addresses are related to the switch.

This might be better.

type Provider interface {
	LivenessProbe(*http.Request) error
	List(context.Context, *v1alpha1.ECSNodeClass) ([]*vpc.DescribeVSwitchesResponseBodyVSwitchesVSwitch, error)
	ZonalSubnetsForLaunch(context.Context, *v1alpha1.ECSNodeClass, []*cloudprovider.InstanceType, string) (map[string]*VSwitch, error)
	UpdateInflightIPs(*ecs.CreateAutoProvisioningGroupRequest, *ecs.DescribeInstancesResponseBodyInstances, []*cloudprovider.InstanceType, []*VSwitch, string)
}

Why not use ecs.CreateAutoProvisioningGroupResponse in UpdateInflightIPs?

• The information in CreateAutoProvisioningGroupResponse is too little, which not only does not meet the requirements of SubnetProvider, but also does not meet the requirements of InstanceProvider.

[daimaxiaxie]

I am a little confused about the name of Alibaba Cloud's VSwitch. It shows different names in different places. So I'm not sure which one is easier for users to understand.
Solicitation for naming:

1. vSwitchSelectorTerms

spec:
  vSwitchSelectorTerms:
    - id: vsw-abc
    - tags: 
        - k: v

2. vswitchSelectorTerms

spec:
  vswitchSelectorTerms:
    - id: vsw-abc
    - tags: 
        - k: v

3. VSwitchSelectorTerms

spec:
  VSwitchSelectorTerms:
    - id: vsw-abc

4. switchSelectorTerms

spec:
  switchSelectorTerms:
    - id: vsw-abc

5. other

@jwcesign @helen-frank @IrisIris