[AKS] improve tab completion for VM sizes

[mboersma]

Currently, hitting [TAB] for a --vm-size-type argument returns all VM sizes available for a location, as returned by the Compute Service. But AKS only supports a subset of those sizes, so the list can be misleading.

This changes the get_vm_size_completion_list completer function to return the intersection of the VM sizes allowed by the ACS SDK with those returned by the Compute Service.

$ az aks create --location eastus -s # [TAB]
$ az aks create --location eastus -s Standard_ # [TAB]
Display all 114 possibilities? (y or n)
Standard_A0             Standard_D12            Standard_D4_v2_Promo    Standard_DS2_v2         Standard_F16
Standard_A1             Standard_D12_v2         Standard_D4_v3          Standard_DS2_v2_Promo   Standard_F16s
Standard_A10            Standard_D12_v2_Promo   Standard_D4s_v3         Standard_DS3            Standard_F1s
Standard_A11            Standard_D13            Standard_D5_v2          Standard_DS3_v2         Standard_F2
Standard_A1_v2          Standard_D13_v2         Standard_D5_v2_Promo    Standard_DS3_v2_Promo   Standard_F2s
Standard_A2             Standard_D13_v2_Promo   Standard_D8_v3          Standard_DS4            Standard_F4
Standard_A2_v2          Standard_D14            Standard_D8s_v3         Standard_DS4_v2         Standard_F4s
Standard_A2m_v2         Standard_D14_v2         Standard_DS1            Standard_DS4_v2_Promo   Standard_F8
Standard_A3             Standard_D14_v2_Promo   Standard_DS11           Standard_DS5_v2         Standard_F8s
Standard_A4             Standard_D15_v2         Standard_DS11_v2        Standard_DS5_v2_Promo   Standard_H16
Standard_A4_v2          Standard_D16_v3         Standard_DS11_v2_Promo  Standard_E16_v3         Standard_H16m
Standard_A4m_v2         Standard_D16s_v3        Standard_DS12           Standard_E16s_v3        Standard_H16mr
Standard_A5             Standard_D1_v2          Standard_DS12_v2        Standard_E2_v3          Standard_H16r
Standard_A6             Standard_D2             Standard_DS12_v2_Promo  Standard_E2s_v3         Standard_H8
Standard_A7             Standard_D2_v2          Standard_DS13           Standard_E32_v3         Standard_H8m
Standard_A8             Standard_D2_v2_Promo    Standard_DS13_v2        Standard_E32s_v3        Standard_NC12
Standard_A8_v2          Standard_D2_v3          Standard_DS13_v2_Promo  Standard_E4_v3          Standard_NC24
Standard_A8m_v2         Standard_D2s_v3         Standard_DS14           Standard_E4s_v3         Standard_NC24r
Standard_A9             Standard_D3             Standard_DS14_v2        Standard_E64_v3         Standard_NC6
Standard_D1             Standard_D3_v2          Standard_DS14_v2_Promo  Standard_E64s_v3        Standard_NV12
Standard_D11            Standard_D3_v2_Promo    Standard_DS15_v2        Standard_E8_v3          Standard_NV24
Standard_D11_v2         Standard_D4             Standard_DS1_v2         Standard_E8s_v3         Standard_NV6
Standard_D11_v2_Promo   Standard_D4_v2          Standard_DS2            Standard_F1   
$ az aks create --location eastus -s Standard_

---

• The PR has modified HISTORY.rst describing any customer-facing, functional changes. Note that this does not include changes only to help content. (see Modifying change log).

[promptws]

View a preview at https://prompt.ws/r/Azure/azure-cli/5393
This is an experimental preview for @microsoft users.

[tjprescott]

One question.

[tjprescott]

If ContainerServiceVMSizeTypes is a static enum, why not just add it as an enum_type instead of doing an API call?

[mboersma]

You mean configure the argument in _params.py with something like get_enum_type(vm_size_types)? Seems like that should be added too. I was just trying to make minimal changes since this completer is shared by three arguments across az acs and az aks.

How does that interact with completer=get_vm_size_completion_list? The behavior in this PR is consistent with before--the list of VM sizes is dynamic, depending on a --location argument or the user's subscription locations.

[tjprescott]

Ah, okay, that makes sense.